WO2001077765A1

WO2001077765A1 - Method and system for remote analysis of control network

Info

Publication number: WO2001077765A1
Application number: PCT/US2000/009644
Authority: WO
Inventors: Jeffrey Ying
Original assignee: I/O Controls Corporation
Priority date: 2000-04-10
Filing date: 2000-04-10
Publication date: 2001-10-18

Abstract

A system and method for monitoring, diagnosing and/or testing a control network (199) using portable, wireless equipment includes computerized display device (194) connected to a wireless intermediary device (196) for allowing a wireless connection to be made to a control network (199). The wireless equipment may allow the operator (193) to force individual system components to output states, and provide for real time monitoring. The portable, wireless equipment is programmed with information pertaining to the connections and locations of the components in the control network (199), thereby simplifying diagnosis or testing by the operator (193).

Description

S P E C I F I C A T I O N

TITLE OF THE INVENTION

METHOD AND SYSTEM FOR PERFORMING REMOTE DIAGNOSTIC

ANALYSIS OF CONTROL NETWORK

BACKGROUND OF THE INVENTION

1) Field of the Invention

The field of the present invention relates to diagnostic and maintenance tools

for control networks.

2) Background

Electronic control systems are commonly used in a number of manufacturing,

transportation, and other applications, and are particularly useful to control

machinery, sensors, electronics, and other system components. Manufacturing or

vehicular systems, for example, may be outfitted with a variety of sensors and

electrical and/or mechanical parts that may need to be activated, deactivated,

monitored, enabled, disabled, adjusted or otherwise controlled when needed to

perform their predefined functions. Control of the various system components is

generally accomplished by providing suitable electronic signals to various actuators,

relays, switches, or other control points within the system. Control systems often

LA-138477.2 ^";'^{' '} require that processes be carried out in a prescribed order, or with a level of

responsiveness, that precludes sole reliance on manual control. Also, such systems

may employ sensors or other components that require continuous or periodic

monitoring or control, and therefore lend themselves to automated or semi-

automated control.

A variety of different network architectures for controlling electronic systems

have been developed or proposed. Examples of various control networks include

programmable logic controller (PLC) based multiplexed control systems in which a

single central processing unit (CPU) is used to control a number of input output (I/O)

modules or network nodes; network-controlled multiplexed control systems in which

a network of interconnected CPUs are used to control a number of I/O modules at

the various network nodes; and hierarchical, master-slave multi-bus control systems,

wherein CPU-driven network nodes are connected together at each bus level in a

loop configuration.

In most control networks, it is necessary to be able to diagnose operational

problems that may occur within the system. Operational problems may result from

wiring faults, component failures (either in the control network or in the components

being controlled by the control network), or logic flaws, among other reasons. Also,

it may be necessary to test the operation of the controls system from time to time,

such as when components are added or removed, or when functionality of the

control system is added or changed.

Traditionally, diagnosis and testing of a control network is carried out by

manual activation of switches, relays or actuators, and observing the results on the

LA-138477.2 input/output devices of the control system. Conventional meters (e.g., an Ohm-

meter) may be used to determine if electrical signals from the control network are

reaching the intended destination(s). Due to the different types of operational

problems that can occur (e.g., wiring fault vs. component failure), and the myriad of

possible places in which a fault or failure could occur, locating the source of an

operational problem can be an extremely slow and laborious process. With the

increasing complexity of control systems and the steadily growing number of

components used in such systems, diagnosis and testing become even more critical

and, in many respects, more difficult.

To conduct a complete manual test or diagnosis of a control system can be

very time consuming and tedious. The test personnel generally need to read

complicated circuit blueprints and locate each relay, switch, actuator or other

component that needs to be tested. Often, multiple relays, switches or actuators will

need to be activated, switched or otherwise positioned to test a particular system

component. In such a case, the test personnel needs to locate and set each such

relay, switch and/or actuator to its proper position, which can be a lengthy process.

In many control systems, simply locating the appropriate switches, relays or actuators

can be difficult, especially if the control system is complex and includes many

components. Also, particularly in the case of on-board control systems used in

vehicles (such as buses or rail cars), the switches, relays or actuators can be located

in inconvenient places and thus hard to find or set to reach manually.

Diagnosis and testing of a control network is sometimes carried out by

connecting a test computer (usually a laptop or other portable computerized device)

LA-138477.2 to a diagnostic and maintenance port of the control network. The test computer is

generally programmed to receive various types of information from the control

network to allow an operator to monitor the functioning of the control system. The

test computer may also be used to download new programming instructions to the

control network via the diagnostic and maintenance port.

An illustration of a test computer set-up for monitoring a control network is

illustrated in FIG. 1. As shown in FIG. 1 , a vehicle 101 (shown in phantom for

convenience of illustration) has a control network 1 10 (shown in solid, dark lines)

with various I/O modules dispersed throughout the vehicle 101. A test computer

103 connects by a cord 106 to a module 1 12 containing the diagnostic and

maintenance port. The test computer 103 is thereby able to monitor the functioning

of the control network 1 10.

FIGS. 2, 3 and 4 are diagrams of test computer set-ups for different control

networks as known in the art. FIG. 2 illustrates a hierarchical, master-slave control

network 120, having a master bus controller (MBC) 125 connected to a common bus

138, which connects various network nodes in a loop configuration. The network

nodes may include, for example, high-speed cell net controller (HCNC) modules 128

and digital input/output (DIO) modules 127, or other types of modules, all of which

generally operate in a slave mode with respect to the common bus 138. The control

network 120 may also include one or more secondary buses (not shown). Further

information about certain types of hierarchical, master-slave control networks may be

found in U.S. Patent 5,907,486 and Japanese Patent documents 10-326259 and 10-

333930, all of which are assigned to the assignee of the present invention and

LA-138477.2 hereby incorporated by reference as if set forth fully herein. The control network

120 may be physically connected to a test computer 123 from time to time through

an RS-485 compatible diagnostic and maintenance port 129, for the purpose of

testing and monitoring the functionality of the control network 120 as generally

described above.

FIG. 3 is a diagram of a PLC-based multiplexed control system 140, in which

a single main central processing unit (CPU) 146 is used to monitor and control a

number of network nodes 150. Each network node 150 typically includes a

programmable logic controller (PLC) which, in turn, monitors various input signals or

conditions (such as temperature, current, speed, pressure and the like) and generates

output signals to various output devices (such as actuators, relays or switches)

through input/output (I/O) modules 152, thus providing localized control at various

network node sites. The main control network CPU 146 communicates with the

PLCs of each of the network nodes 150 over a main system bus 147, and provides

top-level command and control. The main control network CPU 146 may be

physically connected to a test computer 149 from time to time through an RS-232

compatible diagnostic and maintenance port 148, for the purpose of testing and

monitoring the functionality of the control network 140 as previously described.

FIG. 4 is a diagram of a network-controlled multiplexed control system 160 in

which a network of interconnected CPUs 170 are used to control a number of I/O

modules 1 72. A main CPU 166 is connected to other dispersed CPUs 1 70 over a

control area network (CAN) bus or device net 167. The CAN bus or device net 167

may be physically connected to a test computer 169 from time to time through a

LA-138477.2 CAN bus or device net gateway 1 75, which connects to the CAN bus or device net

through a CAN bus or device net test port 168. Testing or monitoring of the

functionality of the control network 160 may thus be carried out, as previously

described.

While the use of a computer to monitor the functioning of a control system

has some advantages, present systems have limitations and drawbacks. For example,

the test computer generally must be kept close to the diagnostic and maintenance

port, due to the cord 106 (as shown in FIG. 1) connecting the test computer to the

diagnostic and maintenance port. This arrangement physically limits where the test

personnel can view relevant information. Thus, test personnel working at the back of

the vehicle 101 , for example, could not view the information being shown on the

test computer 103. Therefore, the test personnel would need to walk back and forth

between the test computer 103 and the pertinent locations of the vehicle 101 in

order to carry out an ongoing test or diagnostic procedure. Further, the test

personnel often need to refer to complicated circuit blueprints to interpret the

information on the test computer 103 and to locate the various locations of interest

within the control network 1 10 of the vehicle 101. Such blueprints are usually in

paper form and are cumbersome to deal with. Cross-referencing between the circuit

blueprints and the information on the test computer 103 takes extra time and effort

on the part of the test personnel, and may be the source of human error in

conducting a test or system diagnosis. Further, the types of testing, monitoring and

diagnosis that can be conducted using a test computer 103, at least as conventionally

practiced, are limited.

LA-138477.2 Some systems for wireless diagnosis or monitoring have been proposed in

contexts such as diagnostic analysis of an automobile or similar vehicle. Examples of

such wireless systems may be found in U.S. Patents 5,758,300 and 5,884,202.

Conventional wireless diagnostic and monitoring systems typically involve a portable

wireless unit that is specifically configured for a single type of application.

Therefore, such portable wireless units are useless for monitoring systems other than

the type for which they are specifically configured. Creating a custom portable

wireless unit for each type of control network can be expensive and time-consuming.

Also, despite being wireless, the type of information and test functionality they

provide is limited, and most, if not all, such wireless systems do not have the

functionality to operate in the context of a sophisticated control network.

Therefore, a need presently exists for a flexible, versatile and simple to use

test and diagnosis tool suitable for either simple or complex control network systems.

SUMMARY OF THE INVENTION

The invention in one aspect provides a system and method for monitoring,

diagnosing and/or testing a control network using portable, wireless equipment.

In one embodiment as disclosed herein, a portable, wireless intermediary

device connects to a diagnostic device which is programmed to allow for diagnosis

and testing of a control network. The diagnostic device preferably is embodied as a

personal digital assistant (PDA) preferably comprising, among other things, an on¬

board computer and a graphical screen display. The portable, wireless intermediary

device includes a line interface (either serial or parallel) to the diagnostic device, and

LA-138477.2 receives, formats and modulates the output of the diagnostic device for

communication over a wireless channel to a wireless interface unit connected to the

control network. The portable, wireless intermediary device thereby enables

wireless communication between the diagnostic device and the control network,

allowing testing, monitoring and/or diagnosis of the control network.

In one embodiment, the portable, wireless equipment is programmed to test,

monitor and/or diagnose a control network. The portable, wireless equipment

preferably comprises a graphical screen display for displaying images to the operator

useful for testing, monitoring and/or diagnosing the control network. The displayed

images may include an illustration of all or part of the control network within the

context of the facility (e.g., building, vehicle, plant, robot, machine or other facility),

to facilitate the operator's testing, monitoring and/or diagnosis of the control

network. The image of the facility may be presented on the graphical screen display

in phantom to allow the operator to easily view the components of the control

network being observed or tested.

In another embodiment, the portable, wireless equipment is programmed to

allow the operator to force individual system components to a desired output state.

By entering various inputs, the operator causes test commands to be conveyed

wirelessly from the portable, wireless equipment to the control network, whereupon

the test commands are relayed to the appropriate system component. If working

properly, the system component changes state to the desired output state. The

portable, wireless equipment is preferably programmed to receive feedback from the

control network over the wireless connection, and to display the states of the

LA-138477.2 relevant switches along the output path to the system component being tested or

observed. The portable, wireless equipment is programmed with information

pertaining to the connections and locations of the components in the control

network, thereby simplifying diagnosis or testing by the operator, and reducing or

eliminating the need for the operator to carry and interpret bulky, cumbersome

manuals and circuit blueprints.

In another embodiment, the portable, wireless equipment includes an

automated procedure for testing a line connection between a diagnostic device

carried by an operator and a portable, wireless intermediary device which facilitates

wireless communication to the control network. The portable, wireless equipment

may also include an automated procedure for testing the wireless connection

between the portable, wireless intermediary device and the control network.

Further embodiments, variations and enhancements are also described herein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating a control network diagnostic technique as

known in the prior art.

FIGS. 2, 3 and 4 are diagrams of different control networks as known in the

art.

FIG. 5 is a diagram illustrating a control network diagnostic technique in

accordance with a preferred embodiment as disclosed herein.

FIG. 6 is a top-level diagram of a remote diagnostic system in accordance with

a preferred embodiment as disclosed herein.

LA-138477.2 FIGS. 7, 8 and 9 are diagrams of the remote diagnostic system of FIG. 6 as

applied to various different types of control networks.

FIG. 10 is a diagram of a preferred wireless intermediary unit for connecting a

remote diagnostic device to a control network, as may be used, for example, in any

of the remote diagnostic systems depicted in FIGS. 6 through 9.

FIG. 12 is a diagram of a preferred handheld, computerized diagnostic device

embodied as a personal digital assistant.

FIG. 13 is an example of a screen image depicting a vehicle outline in relation

to control network nodes and other features.

FIG. 14 is an example of a screen image depicting various control network

components illustrated in a logic ladder format.

FIG. 15 is an example screen image of a main menu as may be used, for

example, in the computerized diagnostic device illustrated in FIG. 12..

FIG. 16 is an example of a logon screen as may be used, for example, in the

computerized diagnostic device illustrated in FIG. 12.

FIG. 1 7 is an example of a bus information input screen as may be used, for

example, in the computerized diagnostic device illustrated in FIG. 12.

FIG. 18 is an example of an input check select screen as may be used, for

example, in the computerized diagnostic device illustrated in FIG. 12.

FIG. 19 is an example of an output check select screen as may be used, for

example, in the computerized diagnostic device illustrated in FIG. 12.

FIG. 20 is an example of an RF test screen as may be used, for example, in the

computerized diagnostic device illustrated in FIG. 12.

LA-138477.2 FIG. 21 is an example of a system help screen as may be used, for example, in

the computerized diagnostic device illustrated in FIG. 12.

FIG. 22 is a software architecture diagram as may be used in the

computerized diagnostic device illustrated in FIG. 12.

FIG. 23 is an example of a logic ladder chart.

FIGS. 24, 25 and 26 are screen images illustrating activation of certain control

network components depicted graphically in a logic ladder format.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Various systems and methods for monitoring, diagnosing and/or testing a

control network using portable, wireless equipment will now be described in

connection with preferred embodiments of the invention.

FIG. 5 is a diagram illustrating concepts of control network diagnosis and/or

testing in accordance with a preferred embodiment as disclosed herein, as

exemplified by a control network system deployed in a mobile vehicle 190 (in this

example, a bus). As illustrated in FIG. 6, the vehicle 190 (shown in phantom) has a

control network 199 (shown in dark, solid lines within the vehicle 190) for

controlling circuitry and system components located throughout the vehicle 190,

much the same as the control network shown in FIG. 1. However, the control

network 199 shown in FIG. 5 also includes a wireless diagnostic and maintenance

linking device (e.g., an radio frequency (RF) driver) 192 for providing a wireless

connection to portable wireless equipment utilized by an operator 193. The wireless

equipment preferably includes a handheld, computerized diagnostic device 194,

LA-138477.2 such as a personal digital assistant (PDA) or similar device which is programmed to

provide testing and diagnostic functionality, and a wireless intermediary device 196.

The computerized diagnostic device 194 connects to the wireless intermediary unit

196 by a connector cord 195 or other suitable means. The wireless intermediary

unit 196 is configured to communicate with the wireless diagnostic and maintenance

linking device 192, thereby allowing wireless communication between the

computerized diagnostic device 194 and the control network 199. The operator 193

can thus, for example, perform at least all of the test and diagnosis operations that

could be performed by connecting a test computer to the control network 199, but

without being restricted as to mobility. The computerized diagnostic device 194 also

preferably includes further functionality as described herein.

FIG. 6 is a top-level block diagram of a remote diagnostic system 200 in

accordance with a preferred embodiment as disclosed herein. As illustrated in FIG.

6, the remote diagnostic system 200 comprises a portable, computerized diagnostic

device 201 (such as a personal digital assistant (PDA)) which is connected to a

wireless intermediary unit 205 for the purpose of allowing wireless communication

with a control network 218. The wireless intermediary unit 205 is configured to

communicate with a wireless diagnostic and maintenance linking device 21 5 which

provides wireless access to the control network 218.

The control network 218 may take the form of any type of network, and may

include, for example, a hierarchical master-slave control network such as depicted in

FIG. 2, a PLC-based control network as depicted in FIG. 3, a CAN bus or device net

control network as depicted in FIG. 4, or any other type of control network,

LA-138477.2 including control networks that are fairly simple or substantially more complex than

those depicted in FIGS. 2, 3 and 4. The wireless diagnostic and maintenance linking

device 215 may itself connect to an existing diagnostic and maintenance port (such

as ports 129, 148 and 168 illustrated in FIGS. 2, 3 and 4, respectively) of the control

network 218, thereby being compatible with control networks 218 which have a

built-in capability for connecting non-wirelessly to a test computer.

FIGS. 7, 8 and 9 are diagrams illustrating concepts of the remote diagnostic

system 200 shown in FIG. 6 as applied to various different types of control networks

218. In FIG. 7, for example, is shown a control network system 240 wherein a

handheld, computerized diagnostic device 241 (preferably embodied as a personal

digital assistant (PDA)) communicates with a hierarchical, master-slave control

network 254 over a wireless communication link. The computerized diagnostic

device 241 is connected to a wireless intermediary unit 243 (preferably embodied as

an RF driver) which preferably has, among other things, an antenna 244 for

facilitating wireless RF communication. The computerized diagnostic device 241

sends commands and other instructions in a digital format to the wireless

intermediary unit 243, which re-formats (if necessary) and modulates the data over

an RF communication link. The wireless diagnostic and maintenance linking device

247 (also preferably embodied as an RF driver) receives the modulated data from the

wireless intermediary unit 243, demodulates the received data and places it in a

format compatible with the control network 254. In the example of FIG. 7, the

control network 254 includes an RS-485 compatible diagnostic and maintenance

port 248, and so the wireless diagnostic and maintenance linking device 247 would

LA-138477.2 place the received information in a format compatible with the RS-485 protocol.

However, any other type of interface between the wireless diagnostic and

maintenance linking device 247 and the control network 254 may also be used.

In a similar fashion, the wireless diagnostic and maintenance linking device

247 receives information from the control network 254, re-formats the information (if

necessary) and modulates it for communication over an RF communication link

(which may be the same or different RF channel as utilized on the forward link). The

wireless intermediary device 243 receives the modulated data from the wireless

diagnostic and maintenance linking device 247, demodulates the received data and

places it in a format compatible with the computerized diagnostic unit 241.

The control network 254 shown in FIG. 7 may comprise any hierarchical,

master-slave network or loop configured network, and may have one or more

common buses, arranged in a single-tier (if one bus) or a multi-tier, hierarchical

architecture. Illustrative (but not exhaustive) examples of various types of control

network architectures that be included as part of the control network 254 are

illustrated and/or described in U.S. Patent 5,907,486, Japanese Patent documents 10-

326259 and 10-333930, and U.S. Patent Application Ser. Nos. 08/854,160 (entitled

"Backup Control Mechanism In A Distributed Control Network"), 08/853,893

(entitled "Fault Isolation and Recovery In A Distributed Control Network"),

08/853,989 (entitled "Multi-Tier Architecture for Control Network"), and 09/442,368

(entitled "Control Network with Matrix Architecture"), all of which are assigned to

the assignee of the present invention and hereby incorporated by reference as if set

forth fully herein.

LA-138477.2 FIG. 8 is a diagram of a similar control network system 260 wherein a

handheld, computerized diagnostic device 261 (preferably embodied as a personal

digital assistant (PDA)) communicates with a PLC-based control network 274 over a

wireless communication link. Similar to the control network system 240 shown in

FIG. 7, in FIG. 8 the computerized diagnostic device 261 is connected to a wireless

intermediary unit 263 (preferably embodied as an RF driver) which preferably has,

among other things, an antenna 264 for facilitating wireless RF communication. The

computerized diagnostic device 261 sends commands and other instructions in a

digital format to the wireless intermediary unit 263, which re-formats (if necessary)

and modulates the data over an RF communication link. A wireless diagnostic and

maintenance linking device 267 (also preferably embodied as an RF driver) receives

the modulated data from the wireless intermediary unit 263, demodulates the

received data and places it in a format compatible with the control network 274. In

the example of FIG. 8, the control network 274 includes an RS-232 compatible

diagnostic and maintenance port 268, and thus the wireless diagnostic and

maintenance linking device 267 would place the received information in a format

compatible with the RS-232 protocol. However, any other type of interface between

the wireless diagnostic and maintenance linking device 267 and the control network

274 may also be used.

A similar sequence of events occurs in the opposite direction to convey

information from the control network 274 to the wireless diagnostic device 261.

Thus, the wireless diagnostic and maintenance linking device 267 receives

information from the control network 274, re-formats the information (if necessary)

LA-138477.2 and modulates it for communication over an RF communication link (which may be

the same or different RF channel as utilized on the forward link). The wireless

intermediary device 263 receives the modulated data from the wireless diagnostic

and maintenance linking device 267, demodulates the received data and places it in

a format compatible with the computerized diagnostic unit 261.

FIG. 9 is a diagram of another control network system 280 wherein a

handheld, computerized diagnostic device 281 (preferably embodied as a personal

digital assistant (PDA)) communicates with a CAN bus (or device net) based control

network 294 over a wireless communication link. Similar to the control network

systems 240 and 260 shown in FIGS. 7 and 8, respectively, in FIG. 9 the

computerized diagnostic device 281 is connected to a wireless intermediary unit 283

(preferably embodied as an RF driver) which preferably has, among other things, an

antenna 284 for facilitating wireless RF communication. The computerized

diagnostic device 281 sends commands and other instructions in a digital format to

the wireless intermediary unit 283, which re-formats (if necessary) and modulates the

data over an RF communication link. A wireless diagnostic and maintenance linking

device 287 (also preferably embodied as an RF driver) receives the modulated data

from the wireless intermediary unit 283, demodulates the received data and places it

in a format compatible with the control network 294. In the example of FIG. 9, the

control network 294 includes a CAN bus or device net compatible diagnostic and

maintenance port 289 and a CAN bus or device net gateway 288, and thus the

wireless diagnostic and maintenance linking device 287 would place the received

information in a format compatible with the CAN bus or device net gateway 288.

LA-138477.2 However, any other type of interface between the wireless diagnostic and

maintenance linking device 287 and the control network 294 may also be used.

A similar sequence of events occurs in the opposite direction to convey

information from the control network 294 to the wireless diagnostic device 281 .

Thus, the wireless diagnostic and maintenance linking device 287 receives

information from the control network 294, re-formats the information (if necessary)

and modulates it for communication over an RF communication link (which may be

the same or different RF channel as utilized on the forward link). The wireless

intermediary device 283 receives the modulated data from the wireless diagnostic

and maintenance linking device 287, demodulates the received data and places it in

a format compatible with the computerized diagnostic unit 281 .

FIG. 10 is a diagram of a preferred wireless intermediary unit 300 for

connecting a remote diagnostic device to a control network, as may be used, for

example, in any of the remote diagnostic systems depicted in FIGS. 6 through 9 (for

example, as wireless intermediary unit 205, 243, 263 or 283). As illustrated in FIG.

10, the wireless intermediary unit 300 preferably comprises a communication

interface 310 which connects by a cord 31 1 to a portable computerized diagnostic

device (such as any of the computerized diagnostic devices 201 , 241, 261 or 281

shown in FIGS. 6, 7, 8 and 9, respectively). The nature of the communication

interface 310 depends upon the nature of the computerized diagnostic device, and

may be, for example, a serial interface (such as an RS-232 or Universal Serial Bus

(USB) interface), a parallel interface or fiber optic interface. The communication

interface 310 is connected to a microprocessor 315 (which includes any necessary

LA-138477.2 RAM, ROM or peripheral components), which in turn connects to a communications

module 325. The wireless intermediary unit 300 also preferably comprises a power

sub-system (unless it receives power from an external source, such as the

computerized diagnostic device), comprising a power supply 321 , a power converter

320 and a power management circuit 322.

In a preferred embodiment, the communications module 325 communicates

over radio frequencies, and thus is, in essence, an RF module. The communications

module 325 preferably comprises a transmitter 236 and a receiver 327, and is

preferably connected to an antenna 330. The receiver 327 may, for example, be a

double conversion superheterodyne variety.

In operation, the wireless intermediary unit 300 acts as a wireless interface

between a computerized diagnostic device and a control network. The wireless

intermediary unit 300 receives information (preferably in a digital format) from the

computerized diagnostic device over the communications interfaced 310, formats

the information for transmission, and modulates the information over a wireless

communication channel. The steps involved in formatting and modulating the

information from the computerized diagnostic unit depend upon the format in which

the information is received, the format in which the receiving device expects the

information, and the nature of the physical link (i.e., the wireless communication

channel). If the communications interface 310 to the computerized diagnostic

device comprises a parallel interface, for example, then the microprocessor 315 may

convert the incoming parallel data into serial data to facilitate transmission by the RF

module 325. In any event, the microprocessor 315 and/or RF module 325 may add

LA-138477.2 header bits, error correction and/or encoding to the message being transmitted. In

the opposite direction, the RF module 325 and/or microprocessor 315 may

demodulate, decode, error check and/or strip header bits from information received

over the wireless channel from the control network.

In a preferred embodiment, the communications interface 310 comprises an

RS-232 compatible interface, which has the advantage of allowing compatibility with

many personal digital assistant (PDA) devices. The microprocessor 315 and/or

communications interface 310 are preferably programmed so as to be compatible

with a Windows CE™ or LINUX compatible platforms as may be used in the

computerized diagnostic device to which the wireless intermediary device 300 is

connected.

The RF module 325 may employ frequency modulation (FM) techniques

and/or spread spectrum encoding and decoding of transmitted signals. The

frequency band may be any that is suitable, such as, for example, 400 MHz, 300

MHz, 900 MHz, or 2.4 GHz. The frequency band may be determined by inserting

the appropriate one of several RF module chips, or else may be made selectable by

the operator using switch settings. A voltage-controlled oscillator (VCO) responsive

to the switch settings may be used to generate the different frequencies.

Alternatively, the switch settings may affect both frequency settings and

communication protocols, so that the same wireless intermediary device 300 can be

used for different types of control networks using different wireless communication

interfaces. Each switch setting can correspond to a specific control network type,

and thus be associated with a specific frequency band and communication protocol.

LA-138477.2 The switch settings can be set manually through switches on the exterior of the

wireless intermediary device 300, or else may be selected through various

configuration options provided on the screen display of the computerized diagnostic

device.

In one embodiment, the power sub-system provides power to the

communication interface 310, microprocessor 315 and RF module 325. A power

supply 321 includes a battery (which can be alkaline or lithium (rechargeable), for

example) or other low voltage power source. In a preferred embodiment, the power

supply 321 comprises a 3.6 volt battery. A power converter 320 is provided to the

voltage level of the 3.6 volt battery to a 5 volt level suitable for the microprocessor

315 and RF module 325. The power management circuit 322, among other things,

determines whether the battery level is high, medium or low. This information may

be made available to the operator through one or more LEDs, a guage, or LCD

display, for example. As an alternative to an on-board power supply 321 , or in

addition thereto, power may also be brought into the wireless intermediary device

300 from an external source, such as the computerized diagnostic device.

The wireless intermediary unit 300 preferably includes a lightweight, durable

moisture-resistant housing or encasement that may be manufactured from any of a

variety of materials, including, for example, plastic or aluminum (or other lightweight

metal). The housing or encasement (not shown) of the wireless intermediary unit

300 preferably includes suitable means for allowing it to be physically carried by an

operator (thus facilitating its transportability), such as, for example, a belt clip, or

small hoops for allowing the fastening of a strap of similar means for securing the

LA-138477.2 wireless intermediary unit 300 to the body of the operator. Alternatively, the

operator may wear a belt having a pouch or pocket for placing the wireless

intermediary unit 300. Because it is generally advantageous for an operator to be

able to carry around the wireless intermediary unit 300, it is preferably small in size,

with on-board components integrated to the extent reasonably possible. It should be

possible to manufacture the necessary circuitry and components for the wireless

intermediary unit 300 in a size similar to that of conventionally available cellular or

pocket telephones, many of which contain microprocessors, RF circuitry and a local

power supply.

It should be noted that generally the wireless intermediary unit 300 will

connect to the computerized diagnostic device by a cord, cable, wire or other

physical means, but in some circumstances a wireless connection between the

wireless intermediary unit 300 and the computerized diagnostic device may be

desirable.

Referring once again to the top-level block diagram in FIG. 6, in accordance

with one or more embodiments as disclosed herein, the computerized diagnostic

device 201 is programmed to test, monitor and/or diagnose a control network 218 by

communicating to the control network 218 through the wireless intermediary device

205. The computerized diagnostic device 201 preferably comprises a graphical

screen display for displaying images, text and other information to the operator

useful for testing, monitoring and/or diagnosing the control network.

An example of operation of the computerized diagnostic device 201 may be

illustrated with respect to the control system 240 shown in FIG. 7, which, it will be

LA-138477.2 recalled, depicts a hierarchical, master-slave control network 254. In this particular

example, the master bus controller (MBC) 250 of the control network 254 normally

operates in a master mode with respect to the common bus 251 , while the other

network nodes 252, 255 normally operate in a slave mode with respect to the

common bus 251 . The master bus controller 250 preferably comprises a pair of

independent processors 350, 351 , a first processor 350 which connects to the

common bus 251, and a second processor 351 which connects to the diagnostic and

maintenance port 248, as illustrated in FIG. 1 1. The first processor 350 acts as a

master with respect to the common bus 251 , while the second processor 351 acts as

a slave (i.e., listener) with respect to the diagnostic and maintenance port connection.

Both processors 350, 351 are connected to a dual-port RAM 355, which stores,

among other things, a test mode status variable 356 indicating whether the master

bus controller 250 is in test mode or not. When a test, diagnosis or other analysis of

the control network 254 is desired, the operator initiates the appropriate commands

through the computerized diagnostic device (preferably using techniques described

later herein), causing a mode switch instruction to be relayed via the wireless

intermediary device 243 and wireless diagnostic and maintenance linking device

247 to the master bus controller 250. The mode switch instruction is received by the

second processor 351 , which interprets the instruction and, in response thereto,

switches the test mode status variable 356 to indicate that the master bus controller

250 is now in test mode. The first processor 350 polls the test mode status variable

356 periodically (e.g., once per millisecond), and, when it observes that the state of

the test mode status variable 356 has switched, enters the test mode.

LA-138477.2 Once the test mode is entered, the master bus controller 250 may operate

with reduced functionality as compared to its normal monitoring, command and

control duties, or may cease performing any monitoring, command and control

functions altogether, depending upon how it is programmed and the criticality of

those functions. The first processor 350 then continually checks for instructions sent

from the computerized diagnostic device 241, which are relayed to it by the second

processor 351 and stored in the dual-port RAM 355 in predefined locations. When

the first processor 350 receives an instruction when in the test mode, it carries it out

and awaits the next instruction. When the test operation is complete (or when the

wireless communication link is broken), the second processor 351 returns the test

mode status variable 356 to its original (i.e., non-test mode) state. The first processor

350, which continues to poll the test mode status variable 356 when in the test

mode, eventually observes that the test mode status variable 356 has returned to its

original state, and, in response thereto, resumes its normal monitoring, command

and control duties.

A variety of other techniques may be used to cause the master bus controller

250 to respond to instructions from the computerized diagnostic device 241 . For

example, the master bus controller 250 may comprise only a single processor, and

the wireless diagnostic and maintenance linking device 247 may have direct memory

access to a test mode status variable stored in the RAM of the master bus controller

250. Alternatively, the master bus controller 250 may receive an interrupt from the

wireless diagnostic and maintenance linking device, and may then check a

predefined instruction buffer to receive test instructions originating from the

LA-138477.2 computerized diagnostic device 241. A variety of other techniques may also be

used. Similar techniques may also be used to initiate test mode operations with any

other type of control network (including the control network systems 260 or 280

shown in FIGS. 8 and 9, respectively).

Further functions and features of the computerized diagnostic device 201 will

now be described, with particular reference to FIG. 12, which illustrates a preferred

such device 201 embodied as a personal digital assistant (PDA) 420, such as a

commercially available PalmPilot^® or other handheld computer device. While this

embodiment is described with respect to a PDA device, it will be understood by

those skilled in the art that any other type of device having the same functionality

may be substituted for the PDA device.

In a preferred embodiment, the personal digital assistant 420 is based on a

platform running Windows CE^®, LINUX, or another suitable operating system 424

capable of supporting the operations of a handheld graphical computing device. The

personal digital assistant 420 also preferably comprises a communication interface

428, which is used to communicate with the wireless intermediary unit 430 through,

for example, a direct wired connection 432 (but alternatively, through a wireless

connection 434 such as a radio frequency (RF) or infrared (IR) connection). The

personal digital assistant 420 also preferably includes a graphical screen display 422,

which may, for example, support a Graphical User Interface (GUI) for allowing user

interaction, and further includes one or more application programs 426 which

provide the programming instructions for executing a variety of the test and

diagnostic functions programmed into the personal digital assistant 420.

LA-138477.2 Some of the test and diagnostic functions that may be included are as follows.

The personal digital assistant 420 may allow the user to view various aspects of the

control network graphically on the screen display 422. The displayed images may

include, for example, illustrations of all or part of the control network within the

context of the controlled facility (e.g., a building, vehicle, plant, robot, machine or

other facility), so as to facilitate the user's testing, monitoring and/or diagnosis of the

control network. The image of the facility may be presented on the screen display

422 in a faint outline or phantom format, while the control network may appear in

solid, dark lines, thus allowing the user to easily distinguish the facility from the

components of the control network being observed or tested.

The personal digital assistant 420 may also provide the ability for an operator

to force individual components in the control network system to a desired output

state. By entering various inputs, the operator may cause test instructions to be

conveyed wirelessly from the personal digital assistant 420 to the control network

218, whereupon the test instructions are relayed to the appropriate individual

component(s) of the control network system. In the absence of any fault of

component failure, the component should change states to the desired output state in

response to receiving the proper instruction. The personal digital assistant 420 may

be programmed to receive feedback from the control network 218 over the wireless

connection, and to display (in a ladder format, e.g.) the states of the relevant

switches, actuators or relays along the signal path to the network component being

tested or observed. The personal digital assistant 420 may be programmed with

information pertaining to the locations of various network components in the control

LA-138477.2 network 218 and their connectivity, thereby simplifying diagnosis or testing by the

operator, and reducing or eliminating the need for the operator to carry and interpret

bulky, cumbersome manuals and circuit blueprints.

The personal digital assistant 420 may also provide an automated procedure

for testing the connection between it and the wireless intermediary device 205 (or

430 in FIG. 12), and another automated procedure for testing the wireless

connection between the wireless intermediary device 205 and the control network

218.

Details of the above functions, and additional test and diagnostic functions,

are provided below.

FIG. 22 is a diagram of a preferred software system architecture as may be

used in the computerized diagnostic device illustrated in FIG. 12. As illustrated in

FIG. 22, the software system architecture 600 comprises a security checking function

605, a main menu function 601 , and a security administration function 607, which

preferably (but need not) collectively comprise a software loop as illustrated. The

main menu function 607 calls any of a number of subsidiary functions, including a

network information function 610, a help function 612, a power function 613, a logo

function 614 and an RF test function 615. All of the foregoing functions 601, 605,

607, 610, 612, 613, 614 and 615 may be viewed as "network independent" in the

sense that they do not depend upon the nature of the control network being tested or

diagnosed. The network information function 610 in turn accesses a variety of

additional subsidiary functions, including a system check function 620, an input

check function 621 , a force output function 622, and a real-time monitoring function

LA-138477.2 623. These latter functions 620, 621 , 622 and 623 may be viewed as "network

dependent" in certain aspects because they may depend or can be optimized for

particular network configurations, types or implementations. Further details

regarding the software functions appearing in FIG. 22 will be described or become

apparent in the discussion of the test and diagnostic functions of the personal digital

assistant 420.

A diagnostic system menu screen 460, as illustrated in FIG. 15, preferably

allows a user to initiate various test and diagnostic functions relating to the control

network 218, as well as to perform various software system administrative functions.

The test and diagnosis application software may have pre-programmed security

functions designed to prevent unauthorized access to the diagnostic system main

menu 460. Examples of security features are described below.

In a preferred embodiment, the security checking function 605 of the personal

digital assistant 420 is invoked during initial user access, and also may be accessed

via user selection of a security function icon from a diagnostic system main menu

(see FIG. 15). The application program relating to the test and diagnosis features of

the personal digital assistant 420 may be launched according to any acceptable

procedure provided by the operating system 424, and is conveniently accomplished

by user selection of an icon relating to the control network test and diagnosis

application software. When a user initially launches the control network test and

diagnosis application software, or when the personal digital assistant 420 is powered

on with the diagnostic system main menu 460 running, a logon screen 480, as

illustrated in FIG. 16, is preferably displayed, prompting the user to enter a logon

LA-138477.2 identification (ID) string in a user ID field 482 and password in a password field 484

in order to gain operational access to the control network test and diagnosis

application software. The security checking function 605 then attempts to verify the

logon ID string and password. If the security checking function 605 is able to verify

the logon ID and password, the user is then allowed to access the screen displaying

the diagnostic system main menu 460, including the associated test and diagnostic

system functions. An example of a diagnostic system main menu is illustrated in FIG.

15. If the user's logon ID and password cannot be verified, the user is denied access

to the features provided by the test and diagnosis application software. Preferably,

the security checking function 605 also continuously monitors each individual user's

activity, and logs off any user who has been inactive for a predetermined period of

time. This automatic log-off timeout function reduces the likelihood that an

unauthorized person can access the test and diagnostic application software by using

a personal digital assistant 420 which has not been properly logged off.

A variety of icons 461 through 472 are shown in the exemplary diagnostic

system main menu 460 illustrated in FIG. 15. Rather than icons, textual strings may

be displayed, listing the various available functions. The icons 461 through 472,

however, are convenient from a user standpoint, and may be selected by, for

example, a wand device, user contact (if a touch screen), pressing an appropriate

keyboard key (for example, entering the first letter(s) of the desired function, or using

the arrow keys to the appropriate icon and pressing enter), vocalizing the desired

input (if a microphone and speech recognition software are provided), or by any

other selection means provided within the functionality of the personal digital

LA-138477.2 assistant 420. The precise manner of selecting the various icons or functions of the

test and diagnosis application software is not important to the overall operation of the

invention in its various embodiments as described herein.

A user may invoke various security functions by selecting the Security icon

469 from the system main menu 460, shown in FIG. 15. If a user has privileges

associated with a system administrator, then selecting the Security icon 469 from the

main menu 460 may enable the user to perform various system administration

functions, such as, for example, adding a new user ID and password, deleting a user

ID, or modifying an existing user's password 484. If the user logs on using a

standard user logon ID (as opposed to a system administrator user ID), selecting the

Security icon 469 from the main menu 460 may enable the user to perform certain

system administrative functions unique to that individual, such as, for example,

modifying his or her existing password 484.

The diagnostic system main menu 460 illustrated in FIG. 1 5 is particularly

tailored, in this example, to the transit vehicle industry, but may be tailored to any

industry, or else may be made generic. In this particular embodiment, however, a

bus (i.e., transit vehicle) information icon 461 is provided as part of the diagnostic

system main menu 460. Alternatively, the bus information icon 461 may be

replaced by a control network information icon, to make its functionality more

generic. A primary purpose of the bus information icon 461 is to allow the user to

identify which transit vehicle (i.e., bus) type will be tested and/or diagnosed, and,

further, which specific transit vehicle within that transit vehicle type will be tested

and/or diagnosed.

LA-138477.2 When the user selects the bus information icon 461 from the diagnostic

system main menu 460, a bus information input screen 490 is preferably displayed,

as illustrated in FIG. 17. The user may then enter a transit vehicle type (or control

network type, more generically) in a transit vehicle type field 492, and a transit

vehicle identification (ID) number (or control network ID, more generically) in a

transit vehicle ID field 494, which identifies the particular vehicle (or other structure

or facility) to be serviced. The transit vehicle type 492 may be entered by the user

(using a numeric keypad in connection with a wand, for example), or alternatively

may be selected from a drop down menu (invoked by selecting a drop down menu

button 496) listing available transit vehicle types. For any given transit vehicle type,

many individual transit vehicles may exist. Entry of a unique transit vehicle ID in the

transit vehicle ID field 494 identifies the specific vehicle to be serviced. The network

information function 610 (see FIG. 22) preferably manages the foregoing transit

vehicle or control network information functions. It preferably responds to the entry

or modification of the transit vehicle ID by verifying that the specified vehicle exists

(i.e., is recognized by the test and diagnosis application software) and that a

communications connection to that vehicle can be established.

In a preferred embodiment, when the user has selected the specific transit

vehicle ID and it has been recognized by the network information function 610, the

personal digital assistant 420 attempts to communicate with the control network 218

of the selected transit vehicle through establishment of a wireless connection by the

wireless intermediary unit 205 (or 430, as depicted in FIG. 12). If the control

network 218 of the specified transit vehicle does not respond to the wireless

LA-138477.2 intermediary unit 205 (or 430), then an error message may be displayed on the

screen image of the personal digital assistant 420, indicating a communications link

failure. Such a failure may be caused by a variety of circumstances, including, for

example, that 1) the specified transit vehicle is not within range of the wireless

intermediary unit 205 (possibly because an incorrect transit vehicle ID is entered), or

2) the communications link itself failed due to mechanical malfunction.

If the specified transit vehicle (or control network) type and transit vehicle (or

control network) ID are verified by the network information function 610, and,

optionally, if a communications link is established to the control network 218, the

network information function 610 may then ensure that the relevant transit vehicle

(or control network) information is available to the personal digital assistant 420. For

example, the network information function 610 may examine a data storage

component (such as an internal ROM/PROM/EEPROM chip or memory card, a CD-

ROM, an insertable memory cartridge, or a disk, to name a few examples) to

determine whether the relevant transit vehicle (or control network) information is

available. The data storage component may store information relating to a single

transit vehicle (or control network), or multiple transit vehicles (or control networks).

If the information pertaining to the selected transit vehicle (or control network) is not

found on the data storage component, then the network information function 610

may cause a message to be displayed on the display screen 422 requesting the user

to insert or otherwise provide the necessary data storage component (i.e., "Please

insert the memory cartridge for the Alpha bus"). Alternatively, the user may

download such information from a host computer (not shown). As yet another

LA-138477.2 alternative, the personal digital assistant 420 may attempt to automatically download

the control network information from a remote host computer. To this end, the

personal digital assistant 420 may be configured with its own wireless

communication interface through which it makes a connection to a remote host

computer at which the relevant control network information is stored. As a variation

of this technique, the wireless intermediary device 205 (or 430) may be provided

with means for establishing a separate wireless communication link to a remote host

computer at which the relevant control network information is stored.

Assuming the transit vehicle (or control network) information is available to

the personal digital assistant 420, the personal digital assistant 420 returns to the

main menu function 601 and displays the diagnostic system main menu 460 for the

user to select desired diagnostic functions to be performed on the vehicle.

Once the control network (e.g., transit vehicle) type and specific ID are

selected, the user may thereafter perform a variety of test or diagnostic activities

utilizing the personal digital assistant 420. In a preferred embodiment, selection of a

system check icon 462 allows the user to graphically observe a diagram of the

control network 218, preferably within the context of the associated transit vehicle or

other facility (e.g., building, plant, robot, etc.). In a preferred embodiment, in

response to selection of the system check icon 462, and as illustrated in FIG. 14,

some or all of the network nodes 442 of the control network 218 are graphically

displayed on screen display 422 of the personal digital assistant 420 in dark, solid

lines, superimposed on a three-dimensional (3-D) transparent or phantom outline

image 440 of the transit vehicle (or other structure or facility which houses the

LA-138477.2 control network 218). Each of the network nodes 442 in the control network may be

numbered or otherwise designated with a unique identifier (e.g., A1 , A2, B1 and so

on) for identification by the user. Graphical display in this manner assists the user in

identifying and locating various network nodes of the control network 218, by

showing their relative positions within the image 440 of the transit vehicle (or other

facility).

The graphical information relating to the image 440 and the network nodes

442 is preferably stored on (or downloaded to) a data storage component within the

personal digital assistant 420. As noted previously, this information may be stored in

ROM, PROM, EEPROM, CD-ROM, memory cartridge, or any other data storage

means accessible to the personal digital assistant 420. In a preferred embodiment,

sufficient graphical information is provided such that the image 440 of the transit

vehicle (or other facility) is fully rotatable, thus allowing the user to change the view

to correspond to wherever the user happens to be positioned in relation to the

vehicle. The user may be allowed, in some applications, to zoom in or out of the

screen image. Likewise, alternative view might be provided, such as an internal view

versus an external view, and the user may be provided with means to select a

particular view.

Selection of the system check icon 462 by the user may also result in a

diagnostic test being initiated by the system check function 620 (see FIG. 22) of the

application software running on the personal digital assistant 420. For example, each

of the network nodes 442 in the control network may be systematically tested by the

control network, according to an instruction relayed from the personal digital

LA-138477.2 assistant 420 to the control network 218 over the wireless communication channel

via the wireless intermediary device 205. This diagnostic test may run in a

continuous loop until terminated by the user by hitting, for example, an Exit button

443. Control nodes 442 identified as malfunctioning during this diagnostic analysis

may be illustrated on the screen display 422 in a distinguishable manner from

properly functioning control nodes 442. This can be accomplished in various ways,

such as by shading the malfunctioning control nodes 442 in a color different than the

normally operating control nodes 442, or by causing the malfunctioning control

nodes 442 to blink on the graphical display 422, or by any other visual or graphical

means. Detection of a malfunctioning control node 442 during system check may

also result in display of an error message on the personal digital assistant 420 alerting

the user of the problem. Once a malfunctioning control node 442 is serviced or

replaced, the displayed error message is cleared, and the nature of the network node

image returns to its original display state.

While the image 440 of the transit vehicle or other facility is preferably

displayed transparently and in 3-D, in various applications this type of graphical

display may not be necessary or desired. Therefore, the image 440 being displayed

may be a schematic diagram, or a two-dimensional image, if desired.

As further illustrated in FIG. 13, the image display software utilized in

connection with the check system function 620 also preferably allows a text layer

(such as "A1 ", "A2", "B1 ", etc.) to be superimposed on the image 440 appearing on

the screen display 422. The text overlay may be used to provide identifying

LA-138477.2 information for the various network nodes 442, or to provide other information to the

user.

Other additional functions preferably provided by the application software

run on the personal digital assistant 420 will now be described. Returning to FIG.

15, user selection of the Input Check icon 463 on the system main menu 460 causes

the display of an input check select screen 500 (as illustrated in FIG. 18) on the

screen display 422. The input check select screen 500 may comprise one or more

pages associated with each network node, listing all of the testable input switches,

actuators, relays, or other components associated with the network node. In a

preferred embodiment, a drop down menu 504 is available at the activation of a

drop down menu button 502, that lists all of the available network nodes of the

control network 218. Using the drop down menu 504, the user selects a particular

network node (e.g., "AC-BO") to be tested. Selection of a network node from the

drop down menu 504 results in one or more pages appearing on the input select

display screen 500 listing all testable input components 506 associated with the

selected network node. The user then indicates the input components 506 to be

tested by selecting the corresponding check box(es) 508 on the page of the input

check select screen 500.

In response to selection of the check boxes 508 for the desired input

components 506 to be tested, the application software of the personal digital

assistant 420 issues commands to the control network 218 (over the wireless

communication link, via the wireless intermediary device 205) to check the status of

the selected input components 506. Upon receiving a response from the control

LA-138477.2 network 218, the input check function 621 of the application software highlights or

otherwise identifies any malfunctioning input components 506 visually on the input

check select screen 500. The operator then may replace the indicated defective

input components 506, or otherwise locate the fault or cause of failure, to repair the

malfunction. Remote testing of control network inputs 506 in this manner is useful

to the operator because often components 506 are located in hard to access places,

particularly in the context of transit vehicles, as well as in many other applications.

The drop down menu 504 on the input check select screen 500 is also useful to the

user as a directory to determine the names of input components 506 and network

nodes of the control network 218.

Returning once again to FIG. 15, user selection of the Output Check icon 464

on the system main menu 460 results in a very similar sequence of events, and,

initially, causes the display of an output check select screen 510 (as illustrated in FIG.

19) on the screen display 422. The output check select screen 510 may comprise

one or more pages associated with each network node, listing all of the testable

output switches, actuators, relays, or other components associated with the network

node. In a preferred embodiment, a drop down menu 514 is available at the

activation of a drop down menu button 512, that lists all of the available network

nodes of the control network 218. Using the drop down menu 514, the user selects

a particular network node (e.g., "BA-IN") to be tested. Selection of a network node

from the drop down menu 514 results in one or more pages appearing on the input

select display screen 510 listing all testable output components 516 associated with

the selected network node. The user then indicates the output components 516 to

LA-138477.2 be tested by selecting the corresponding check box(es) 518 from the first column of

check boxes on the page of the input check select screen 510.

In response to selection of the check boxes 518 for the desired output

components 516 to be tested, the application software of the personal digital

assistant 420 issues commands to the control network 218 (over the wireless

communication link, via the wireless intermediary device 205) to activate all

necessary input components (e.g., switches) to force the selected output function.

The application software of the personal digital assistant 420 then issues commands

to the control network 218 (again over the wireless communication link, via the

wireless intermediary device 205) to check the status of the selected output

components 516. Upon receiving a response from the control network 218, the

output check function 622 of the application software highlights or otherwise

identifies any malfunctioning output components 516 visually on the output check

select screen 510. The operator then may replace the indicated defective output

components 516, or otherwise locate the fault or cause of failure, to repair the

malfunction. As with the Input Check function, the Output Check function provides

the benefit of remote testing, which is very convenient for operational personnel.

Further, the drop down menu 514 on the output check select screen 510 is also

useful to the user as a directory to determine the names of output components 506

and network nodes of the control network 218.

In the case of output state failure, the Output Check function of the

application software running on the personal digital assistant 420 allows interactive

real time monitoring of the output functions 516. The real time monitoring function

LA-138477.2 is activated by the user selecting the appropriate check box(es) 518 in the second

column on the output check select screen 510 corresponding to the failed output

516. Real time monitoring can also be selected directly from the diagnostic system

main menu screen 460 shown in FIG. 1 5.

In a preferred embodiment, the real time monitoring feature of the personal

digital assistant 420 preferably provides the ability to display a graphic, visual

diagram, in "logic ladder" format, of the on/off states of selected control network

components. Although many different formats could be chosen, a logic ladder

format is particularly useful for diagnostic and maintenance personnel. FIG. 23 is an

example of a logic ladder chart, showing various conditions that are required to

activate a starter relay ("E3-3"). Such conditions, in this example, include at least the

following: (1) alternator is not charging; (2) vehicle is in neutral; and either (3) the

master switch is on, the ignition and starter controller switches are set in front start

positions, and the starter button is on; or (4) the rear ignition and starter switches are

set in start position.

FIG. 14 shows a real time monitoring screen 450 displayed by the application

software running on the personal digital assistant 420 in response to selection of the

Real Time Monitoring function. The real time monitoring screen 450 preferably

displays a set of input elements 456 (i.e., conditions) and the corresponding system

output 458, in a logic ladder format. In this embodiment, the input elements 456 of

the circuit are highlighted to illustrate that the element is operating properly. This

function allows real time monitoring of input components and output components

within the control network 218.

LA-138477.2 In a preferred embodiment, a control module drop down menu 452 is

available by selecting a drop down menu button 451 , providing a list of all network

nodes of the control network 218. The user may thereby select a particular network

node for diagnostic testing. When a network node is selected, a network node

output drop down menu 453 is displayed, providing a list of all system outputs for

the selected network node. The user may then scroll through the list and select a

particular system output to be tested using the real time monitoring function.

In a preferred embodiment, the real time monitoring function displays a

graphical diagram of the logic ladder format diagram including all input elements

456 (i.e., conditions) required to activate the selected output 458, displayed as

symbols on the real time monitoring screen 450. From the logic ladder diagram, the

user then may individually select each input element 456 to perform real time

diagnostic testing of each input element 456. If the element is functioning properly,

then its corresponding symbol on the real time monitoring screen 450 illuminates or

becomes otherwise visually distinguished. If the switch is defective, it will not

illuminate or becomes otherwise visually distinguished in a manner indicated that it

is not operating. This function allows fast and convenient real time diagnostic

monitoring of a complete circuit, from the input elements 456 to the system output

458, in all possible input combinations.

FIGS. 24, 25 and 26 show examples of screen images illustrating activation of

certain input elements depicted symbolically within a logic ladder format, eventually

leading to activation of an output component (i.e., back-up light). In FIG. 24, the

initial logic ladder diagram is illustrated for the user on the screen display 422. The

LA-138477.2 user then may select the first input element or switch ("MBC-1 "), causing it to

become visually distinguishable, as illustrated in FIG. 25 (in this particular example,

it becomes shaded, but it can as easily be illuminated or color coded as well). Then,

the user may select the second input element or switch ("MBC-13"), causing it to

become visually distinguishable, as illustrated in FIG. 26. When the inputs have

been so activated, the output state of the output component (i.e., backup light) can

be checked.

To carry out the Real Time Monitoring function, as each input element is

selected by the user, the application software sends the appropriate commands

across the wireless connection (via the wireless intermediary device 205 or 430) to

the control network 218, which responds by activating the appropriate switch or

component. The control network 218 can send a response to the personal digital

assistant 420 as each switch or component is activated, or else the application

software can periodically poll the status registers at the control network to determine

when the switch or component has activated or reached its desired state.

As noted, the real time monitoring select function may be invoked for a

particular system output by selecting the check box 518 (in the second column) for

the output 458 on the output check select screen 510, shown in FIG. 19. In

response to selection of one or more real time monitoring options using the check

boxes 518, the application software automatically displays the real time monitoring

select screen 450 on the screen display 422 of the personal digital assistant 420, with

the corresponding logic ladder diagram (i.e., switch hierarchy) for the selected

system output 458. When multiple system outputs 458 are selected, the application

LA-138477.2 software may rotate through the corresponding logic ladder diagrams sequentially, or

may allow the user to scroll through them until the desired screen is found.

Allowing direct access from the Output Check function to the Real Time Monitoring

function eliminates the need for a user to select the network node and system output

453 each time on the Real Time Monitoring select screen 450, thereby increasing the

efficiency of testing multiple system outputs 458 and their corresponding input

elements 456.

Returning once again to FIG. 15, user selection of the RF Test icon 472 (or

communication link test icon) on the diagnostic system main menu 460 displays an

RF test screen on the personal digital assistant 420. An example of a preferred RF

test screen 520 is shown in FIG. 20. The RF test screen 520 preferably activates an

RF test function, which verifies the integrity of the connection both between the

personal digital assistant 420 and the wireless intermediary unit 430, and the

connection between the wireless intermediary unit 430 and the control network 218.

A simple checksum or other error detection technique may be used. Any errors

detected in these communication links cause the RF test function 615 of the

application software to generate an error message on the RF test screen 520 of the

personal digital assistant 420, thereby alerting the user of a potential problem. .

Various miscellaneous features are also preferably provided in connection

with the test and diagnostic features. For example, returning again to FIG. 15, user

selection of a Power icon 467 on the diagnostic system main menu 460 may act to

shut down the power to the personal digital assistant 420. User selection of a Help

icon 466 on the diagnostic system main menu 460 displays a system help screen 530

LA-138477.2 on the screen display 422 of the personal digital assistant 420, an example of which

is illustrated in FIG. 21. The help screen 530 provides on-line help for the various

functions provided by the test and diagnosis application software running on the

personal digital assistant 420. A scroll-down menu of help topics may be provided,

from which the user may make a selection in order to get further information on the

topic.

It is thus apparent that a versatile, flexible and robust system has been

provided for allowing remote testing and diagnosis of control networks and similar

electronic systems. The various features provided as a result of the disclosed

embodiments enhance allow for more convenient, rapid, efficient and reliable testing

of control networks. Information is presented in an easily understandable format, and

a convenient man-machine interface is provided.

While preferred embodiments of the invention have been described herein,

many variations are possible which remain within the concept and scope of the

invention. Such variations would become clear to one of ordinary skill in the art

after inspection of the specification and the drawings. The invention therefore is not

to be restricted except within the spirit and scope of any appended claims.

Claims

CLAIMSWhat is claimed is:

1 . A remote diagnostic system for testing and diagnosing a control

network, comprising:

a computerized diagnostic device;

a wireless linking device connected to the control network; and

a wireless intermediary device connected to the computerized diagnostic

device, the wireless intermediary device providing a wireless communication link

between the computerized diagnostic device and the wireless linking device

connected to the control network.

AMENDED CLAIMS

[received by the International Bureau on 7 December 2000 (07.12.00); original claim 1 amended; new claims 2-44 added (12 pages)]

1. A remote diagnostic system for testing and diagnosing a control

network, comprising:

a self-contained, portable, computerized diagnostic device;

a wireless linking device connected to the control network; and

a self-contained, portable, wireless intermediary device physically connected

to the computerized diagnostic device through a wired connection, the wireless

intermediary device providing a wireless communication link between the

computerized diagnostic device and the wireless linking device connected to the

control network.

2. The remote diagnostic system of claim 1 , wherein said control network

resides in a transit vehicle, said control network providing on-board monitoring and

control functions for the transit vehicle.

3. The remote diagnostic system of claim 1 , wherein said computerized

diagnostic device comprises a screen display.

4. The remote diagnostic system of claim 3, wherein said computerized

diagnostic device is configured to display images of the control network on said

screen display.

5. The remote diagnostic system of claim 4, wherein said control network

resides in a transit vehicle, and wherein the images of the control network are

displayed on said screen display simultaneously with phantom images of the transit

vehicle.

6. The remote diagnostic system of claim 3, wherein said computerized

diagnostic device is configured to transmit test commands via the wireless

intermediary device to said wireless linking device connected to the control network,

the control network responding to said test commands by activating selected output

functions.

7. The remote diagnostic system of claim 6 further comprising a user

interface, said computerized diagnostic device configured to accept said test

commands via the user interface.

8. The remote diagnostic system of claim 7, wherein said computerized

diagnostic device is configured to display a listing of network nodes of the control

network on said screen display, and to display a listing of testable output functions

on said screen display in response to user selection of one of said network nodes.

9. The remote diagnostic system of claim 8, wherein, in response to user

selection of one of said testable output functions, said computerized diagnostic

device transmits test commands to the control network, via said wireless intermediary device and the wireless linking device connected to the control

network, to activate all necessary network components to force the selected output

function.

10. The remote diagnostic system of claim 7, wherein said computerized

diagnostic device is configured to display logic ladder diagrams of network

components of the control network on said screen display, said logic ladder diagrams

illustrating at least one output function and on/off states of network components

needed to force the at least one output function.

1 1. The remote diagnostic system of claim 10, wherein said computerized

diagnostic device is configured to provide real-time monitoring of said at least one

output function and the on/off states of the network components needed to force the

at least one output function.

12. The remote diagnostic system of claim 10, wherein said computerized

diagnostic device is configured to accept user commands to change the on/off states

of network components displayed in said logic ladder diagrams, said computerized

diagnostic device responding to said user commands by transmitting to the control

network, via said wireless intermediary device and said wireless linking device,

commands to change the on/off states selected by the user.

13. The remote diagnostic system of claim 12, wherein said computerized

diagnostic device is configured to visually depict on said logic ladder diagrams

whether the on/off states of the network components selected by the user have been

successfully changed.

14. The remote diagnostic system of claim 1 , wherein said wireless

intermediary device comprises a standard communication interface for

communicating with the computerized diagnostic device over the wired connection,

and a transceiver for wirelessly communicating with the control network via said

wireless linking device.

15. The remote diagnostic system of claim 14, wherein said standard

communication interface comprises an RS-232 interface.

16. The remote diagnostic system of claim 14, wherein said standard

communication interface comprises a universal serial bus interface.

1 7. The remote diagnostic system of claim 1 , wherein the control network

comprises a multi-tier master-slave control network, said multi-tier master-slave

control network comprising

a first-tier common bus;

a first-tier master node connected to said first-tier common bus;

a plurality of first-tier slave nodes connected to said first-tier common bus; a second-tier common bus; and

a plurality of second-tier slave nodes connected to said second-tier common

bus;

wherein at least one of said first-tier slave nodes functions as a first-tier master

node with respect to said second-tier common bus.

18. The remote diagnostic system of claim 1 7, wherein said wireless

linking device comprises a wireless processor, said wireless processor in

communicating relationship with said first-tier master node of the control network.

19. The remote diagnostic system of claim 18, further comprising a mode

flag accessible to both the wireless processor and the first-tier master node of the

control network, said mode flag controlling operation of the control network in either

a test mode or a non-test mode.

20. The remote diagnostic system of claim 1 , wherein said computerized

diagnostic device comprises a personal digital assistant.

21. A method of testing and diagnosing a control network, said method

comprising the steps of:

transmitting diagnostic commands from a self-contained, portable,

computerized diagnostic device to a self-contained, portable, wireless intermediary

device through a wired connection; transmitting the diagnostic commands from the wireless intermediary device

over a wireless communication link to a wireless linking device connected to the

control network;

receiving, at the wireless intermediary device, diagnostic response messages

from the wireless linking device over the wireless communication link; and ~"~^"

transmitting the diagnostic response messages from the wireless intermediary

device to said computerized diagnostic through the wired connection.

22. The method of claim 21 , wherein said control network resides in a

transit vehicle, said control network providing on-board monitoring and control

functions for the transit vehicle.

23. The method of claim 21 , wherein said computerized diagnostic device

comprises a screen display.

24. The method of claim 23, further comprising the step of displaying

images of the control network on said screen display.

25. The method of claim 24, wherein said control network resides in a

transit vehicle, said method further comprising the step of displaying the images of

the control network on said screen display simultaneously with phantom images of

the transit vehicle.

26. The method of claim 23, further comprising the step of transmitting test

commands from said computerized diagnostic device via the wireless intermediary

device to said wireless linking device connected to the control network, and causing

the control network to activate selected output functions in response thereto.

27. The method of claim 26, further comprising the step of accepting said

test commands via a user interface of said computerized diagnostic device.

28. The method of claim 27, further comprising the steps of displaying a

listing of network nodes of the control network on said screen display of the

computerized diagnostic device, and displaying a listing of testable output functions

on said screen display in response to user selection of one of the network nodes

displayed on said screen display.

29. The method of claim 28, further comprising the step of transmitting

from said computerized diagnostic device, via said wireless intermediary device and

the wireless linking device connected to the control network, and in response to

user selection of one of said testable output functions, test commands to the control

network to activate all necessary network components to force the selected output

function.

30. The method of claim 27, further comprising the step of displaying logic

ladder diagrams of network components of the control network on said screen display of the computerized diagnostic device, said logic ladder diagrams illustrating

at least one output function and on/off states of network components needed to force

the at least one output function.

31. The method of claim 30, further comprising the step of monitoring said

at least one output function and the on/off states of the network components needed

to force the at least one output function in real time on the screen display of the

computerized diagnostic device.

32. The method of claim 30, further comprising the step of receiving user

commands at said computerized diagnostic device to change the on/off states of

network components displayed in said logic ladder diagrams, and the step of

transmitting to the control network, via said wireless intermediary device and said

wireless linking device, commands to change the on/off states selected by the user in

response to receiving said user commands.

33. The method of claim 32, further comprising the step of visually

depicting on said logic ladder diagrams whether the on/off states of the network

components selected by the user have been successfully changed.

34. The method of claim 21, wherein the control network comprises a

multi-tier master-slave control network, said multi-tier master-slave control network

comprising a first-tier common bus;

a first-tier master node connected to said first-tier common bus;

a plurality of first-tier slave nodes connected to said first-tier common bus;

a second-tier common bus; and

a plurality of second-tier slave nodes connected to said second-tier common

bus;

node with respect to said second-tier common bus.

35. The method of claim 21 , wherein said wireless linking device

comprises a wireless processor, said wireless processor in communicating

relationship with a master node of the control network, further comprising the step of

adjusting a mode flag accessible to both the wireless processor and the master node

of the control network in order to control operation of the control network in either a

test mode or a non-test mode.

36. A remote diagnostic system for testing and diagnosing a control

network, comprising:

a wireless linking device connected to the control network; and

a computerized diagnostic device for testing and diagnosing the control

network over a wireless communication link, said computerized diagnostic device

comprising a screen display and an interface for accepting user commands, wherein

said computerized diagnostic device is configured (i) to display a listing of network nodes of the control network on said screen display, (ii) to display a listing of testable

output functions on said screen display in response to user selection of one of said

network nodes, and (iii) to transmit test commands to the control network, via said

wireless linking device and in response to user selection of one of said testable

output functions, to activate all necessary network components to force the selected

output function.

37. The remote diagnostic system of claim 36, further comprising a self-

contained, portable, wireless intermediary device connected to the computerized

diagnostic device through a wired connection, the wireless intermediary device

providing said wireless communication link between the computerized diagnostic

device and the wireless linking device connected to the control network.

38. The remote diagnostic system of claim 36, wherein said control

network resides in a transit vehicle, said control network providing on-board

monitoring and control functions for the transit vehicle.

39. The remote diagnostic system of claim 38, wherein said computerized

screen display simultaneously with phantom images of the transit vehicle in a

manner so as to illustrate the relative locations of network nodes in the transit

vehicle.

40. The remote diagnostic system of claim 39, wherein said images of the

control network are automatically selected by said computerized diagnostic device in

response to entry by a user of data identifying the control network from among a

plurality of control networks.

41. The remote diagnostic system of claim 36, wherein said computerized

diagnostic device is configured to display logic ladder diagrams of network

needed to force the at least one output function.

42. The remote diagnostic system of claim 41 , wherein said computerized

at least one output function.

43. The remote diagnostic system of claim 41 , wherein said computerized

network, via said wireless linking device, commands to change the on/off states

selected by the user.

44. The remote diagnostic system of claim 43, wherein said computerized

successfully changed.