EP0621562A1 - Two-part franking machine - Google Patents

Abstract

Franking machine containing a first so-called "head" part containing franking means controlled by a first microprocessor (50), a keyboard (22) and a display (21) and a second so-called "base" part containing a second microprocessor (53), the first and second microprocessors implementing, in a so-called "normal" mode of operation, a communication protocol adapted so as to cause messages representing at least some of the commands input at the keyboard (22) to be transmitted to the base and to cause the commands executable by the head to be retransmitted from the base to the head, so that, from the keyboard (22) of the head, it is not possible to control at least certain functions unless the commands relating to such functions travel via the base (12). <IMAGE>

Description

The present invention relates to a franking machine comprising in particular a first part called "franking head" and a second part called "base", a keyboard associated with the first part and means of communication connecting these parts.

Such an arrangement, known, makes it possible to distribute between the head and the base the functions provided by the franking machine. Thus, the head performs the strictly postal functions, in particular the sensitive accounting and printing functions, which must be protected against any attempt at fraud or accidental deterioration of the information, while the base performs most of the non-sensitive functions, ie that is, not requiring the same level of security.

The base is also likely to include a set of electronic cards allowing the management of peripherals such as a distributor of labels with electronic preselection, a printer, a postal scale, etc ...

The means of communication allow the base and the head to exchange, bidirectionally, all the information required for the proper functioning of these elements.

The head comprises a microprocessor programmed, in particular so as to ensure the highly secure postal functions, in particular the evolution of the accounting registers, and in particular that comprising the state of the postal account of the user at any time and updated after each transaction of 'postage. There is also a program allowing the modification of the content of these registers, and in particular of the account statement register, on the occasion of the "reloading" of the machine in postal funds.

To ensure dialogue between the operator and the franking machine, the head includes input means, such as a keyboard, and display means.

In general, the header software is highly protected, to prevent any attempt at fraud.

Furthermore, we know that the postal head must imperatively be subject to the approval of the postal administrations. When this approval is obtained, it is not easy to modify or add new functions to an approved machine in order to make it evolve. In this perspective, moreover, the software of the head is frozen. And if we want to change the characteristics of the machine, it is therefore desirable not to have to modify this software.

From another perspective, it is always very difficult to provide means in order to make the franking machine conform to the various foreign postal regulations without modifying the header software. However, for manufacturing imperatives, it is desirable that the software of the head of the machines intended for the French postal administration and of the machines intended for the foreign administrations is the same.

The present invention aims, in this perspective, to make scalable, in particular by adding new functions, a franking machine whose head software cannot be modified.

Another object is to be able to reconfigure, if necessary, the keyboard of the head, and to use the latter both to control the postal and non-postal functions specific to the base.

Another object is also to be able to select particular functions which may be available to a user in a certain country, but not in others.

Another object is to be able to translate the indications appearing on the display screen into several languages, without having to modify the head for this.

These objects are achieved by a franking machine, the structure of which was briefly recalled above, characterized in that the first and second microprocessors implement, in a so-called "normal" operating mode, a communication protocol suitable for transmitting to the base of messages representative of at least some of the commands entered on the keyboard and to have the commands executable by the latter retransmitted from the base, so that from the head keyboard it is not possible to command at the minus certain functions, without the commands relating to such functions passing through the base.

According to the invention, the machine can also be characterized in that, on the one hand, said first microprocessor is arranged so that, in a so-called "normal" operating mode, it identifies the key or keys struck, and cause one or more messages representative of the identification to be transmitted to the base by said means of communication, while, on the other hand, said second microprocessor is arranged to interpret the messages received, and to make transmit, through said means of communication , one or more messages representative of orders executable by the first microprocessor, so that from the head keyboard it is not possible, in said normal operating mode, to command any function at least in relation to the franking, without the command of these functions passing through the base.

Thanks to these provisions, the commands entered by the user on the keyboard are, before their execution by the head microprocessor, transmitted to the base microprocessor, which takes care of transmitting an execution message to the head microprocessor. In this way, we can prevent the execution by the head of certain orders typed on the keyboard of this one, by preventing the emission by the base of the corresponding messages, but we will observe that to do this, we did not modify the software contained in the program memory of the first microprocessor.

In addition, it is easy to reconfigure the keyboard (for example switching from an AZERTY keyboard to a QWERTY keyboard) by modifying the only program contained in the database.

• la figure 1 est une vue schématique illustrant l'agencement des principaux moyens mécaniques d'une machine à affranchir mettant en oeuvre l'invention ;
• la figure 2 est une vue de dessus schématique et simplifiée de la machine illustrée en figure 1,
• la figure 3 est un schéma ilustrant l'organisation matérielle d'une partie de la machine à affranchir faisant l'objet des figures 1 et 2 ;
• la figure 4 est un diagramme fonctionnel illustrant l'interaction des deux parties de la machine, conformément à l'invention.

The characteristics and advantages of the invention will become apparent from the description which follows with reference to the accompanying drawings, in which:

• Figure 1 is a schematic view illustrating the arrangement of the main mechanical means of a franking machine implementing the invention;
• FIG. 2 is a schematic and simplified top view of the machine illustrated in FIG. 1,
• Figure 3 is a diagram illustrating the material organization of a part of the franking machine which is the subject of Figures 1 and 2;
• FIG. 4 is a functional diagram illustrating the interaction of the two parts of the machine, in accordance with the invention.

By definition, the invention is implemented in a franking machine of conventional structure comprising two parts, a first called "head", and a second called "base". In Figures 1 and 2, the main elements of such a machine have been shown schematically for the record, it being specified that on the date of filing of this application, the person skilled in the art is well versed in franking machines in two parts. In these figures, the head is shown diagrammatically under the reference 11, while the base is shown diagrammatically under the reference 12.

The base 12 comprises a housing-structure shown diagrammatically under the reference 13 supporting, in a manner known per se, a motor 14, a connector 15 for connection to peripherals (not shown), a connector 18 for electrical connection with the head 11 and a connector 17a for logical connection with this head.

The franking head 11 comprises a casing-frame shown diagrammatically under the reference 20. Conventionally, the head 11 comprises, arranged in this casing, a display 21 and a keyboard 22 which comprises, in this embodiment, a on the one hand, numeric keys and, on the other hand, functional keys. In another embodiment, the keyboard can also include alphabetic keys configured, for example, in the form of QWERTY. Conventionally, the head 11 comprises a franking mechanism itself comprising a franking tree shown diagrammatically under the reference 24, a mechanism 23 for adjusting the franking value by means of a stepping motor (not shown in this figure, but corresponding to that described in European patent 0.181.804), a device 26, 27, 28 for driving letters or labels to be franked, essentially comprising the schematic rollers, a table for guiding and ejecting letters franking, shown diagrammatically under the reference 29, (having a corresponding part 30 in the base, so as to form a continuous table) and a feeler device 25 for detecting the passage of the envelopes. One of these envelopes is shown diagrammatically in FIG. 1 under the reference 150.

The base also includes a member 14a for transmitting the torque from the motor 14 to the head 11. The transmission member 14a (FIG. 2) is connected to a power take-off device 31 which is itself connected, by means of various shafts shown diagrammatically under the references 32-34, the set of rollers 26-28 and the franking shaft 24 by a clutch shown diagrammatically under the reference 35. The clutch 35 receives the driving force by a pair of gears 35a and 35b. The clutch 35 is controlled by a release device, not shown.

In a manner known per se, the head and the base comprise electronic cards themselves comprising microprocessors ensuring the various functions of the franking machine.

In the head, the electronic cards shown schematically in Figure 1 under the reference 80; they are connected to the connector 18, for electrical connection, and to a connector 17b, for logical connection, with the base. The electronics 80 of the head are connected to the output of the triggering device, as well as to an organ, shown diagrammatically under the reference 40 for franking value control (in this case described in the patent of the applicant FR- 2,645,267). The member 40 monitors, as explained in this document, the mechanism 23 for setting the postage value. The electronics 80 of the head are also connected to the display 21 and to the keyboard 22.

The electronics of the base, shown diagrammatically under the reference 90, provide the various functions specific to it, in particular the management functions of certain peripherals (for example scales, label dispensers, etc.).

All of these provisions recalled above have been perfectly conventional for fifteen years in the field of franking machines and need not be described in detail here. The description of such an arrangement can moreover be found interalia in various patents previously filed, including GB-1,508,623, the descriptions of which are incorporated here.

We will now describe, with the support of FIGS. 3 and 4, the improvement brought by the present invention to franking machines of the type of that mentioned above.

Figure 3 is a schematic representation of the franking machine which has just been described in support of Figures 1 and 2. In this figure, there is shown some means necessary for understanding the present invention.

• à l'afficheur 21,
• au clavier 22,
• à des moyens de communication 51. Ces moyens de communication comportent d'une part, des moyens d'émission 51a et d'autre part, des moyens de réception 51b, gérés par le microprocesseur 50 et reliés au connecteur 17b,
• à une mémoire permanente 70 pour mémoriser les données postales,
• à une mémoire RAM comportant notamment :

• . une zone 59 dite tampon de clavier, mémorisant les touches du clavier qui ont été utilisées,
• . une zône 71 dite masque clavier, mémorisant les touches autorisées de ce clavier,
• . une zone 72 dite masque d'allumage des diodes luminescentes associées au clavier,
• . une zone 73 contenant des drapeaux figurant l'état de divers organes ou fonctions de la machine,
• . une zône 74 servant de mémoire de travail pour les diverses fonctions remplies par le microprocesseur 50.

The electronics 80 of the head essentially comprises a masked microprocessor 50, that is to say provided with its program engraved on the same electronic chip, connected in particular:

• on display 21,
• on keyboard 22,
• to communication means 51. These communication means comprise on the one hand, transmission means 51a and on the other hand, reception means 51b, managed by the microprocessor 50 and connected to the connector 17b,
• to a permanent memory 70 for storing the postal data,
• to a RAM memory comprising in particular:

• . a zone 59 known as the keyboard buffer, memorizing the keys of the keyboard which have been used,
• . an area 71 known as the keyboard mask, memorizing the authorized keys of this keyboard,
• . a zone 72 known as the mask for lighting the light-emitting diodes associated with the keyboard,
• . an area 73 containing flags representing the state of various organs or functions of the machine,
• . a zone 74 serving as working memory for the various functions fulfilled by the microprocessor 50.

The keyboard buffer 59 consists of a two-byte register ( X ₁, X ₂) (see Annex II); between two resets, there is a copy in this register of the keys which have been pressed, so as to reproduce a map of all the keys which have been pressed at least once.

The keyboard mask 71 ( Y ₁, Y ₂) comprises a register of two bytes, the bits of which are assigned in the same way as those of the buffer; these bits, depending on their position, authorize or inhibit each key on the keyboard.

The mask 72 for lighting the light-emitting diodes associated with the keyboard (see Annex I) is a register comprising two bits per diode, ie two bytes ( Z ₁, Z ₂) for eight diodes (limited to six diodes, in this embodiment ); when the two bits are in the same state, the diode is on (logic state "1") or off (logic state "0") and when they are in a different state, the diode flashes.

• à des moyens de communication 54. Ces moyens de communication, qui sont reliés au connecteur 17a, comportent des moyens d'émission 54a et des moyens de réception 54b gérés par le microprocesseur 53,
• à des moyens, de structure connue en soi, de gestion de périphériques associés à la base. Ces moyens de gestion sont schématisés sous la référence 55,
• et à d'autres moyens destinés à assurer les fonctions classiques attribuées en général à la base. Ces autres moyens sont illustrés sous la référence 56.

Similarly, the electronics 90 of the base 12 includes a microprocessor 53 and its program memory 57 linked in particular:

• to communication means 54. These communication means, which are connected to the connector 17a, comprise transmission means 54a and reception means 54b managed by the microprocessor 53,
• to means, of a structure known per se, for managing peripherals associated with the base. These management means are shown diagrammatically under reference 55,
• and other means intended to perform the conventional functions generally assigned to the base. These other means are illustrated under reference 56.

It is again observed that the keyboard and base are connected by means of communication 51, 54 which are themselves linked together by a serial link formed here by the connectors 17a and 17b for logical connection.

The present invention implements a particular cooperation of microprocessors 50, 53 and communication means 51, 54, in order to allow the use of the keyboard 22 and the display 21 to command or control the functions performed both by the head only from the base while giving the latter control of operations, insofar as postal security is not affected. This organization also aims to allow the reconfiguration on the one hand, of the keyboard 22 and on the other hand, of the display formats of the display 21.

The microprocessors 50 and 53 are programmed to perform the various postal and management functions.

The program memory of the microprocessor 50 which is masked as was said above, contains the programs which manage and control the postal operations and functions (setting of the value of the postage, management of the ascending and descending counter as well as error codes related to these functions). They also manage and control the keyboard 22 and the display 21 (scanning of the keys on the keyboard to locate a key pressed, sending to the display of the characters to be displayed and of control codes). These programs finally manage the communication means 51, and in particular the recognition of the codes received to call this or that function.

The program memory of the base microprocessor 53 is not masked. The contained programs generate all the non-postal functions such as peripheral management (for example: label dispenser, printer, balance, accounting head). The various messages to be transmitted are also generated by these programs; these messages allow control of all head functions, including the display and keyboard.

We will now describe the characteristics specific to the invention implemented in the mode of realization of the franking machine chosen and shown in the drawings.

As explained above, one aspect of the invention resides in a communication protocol between head 11 and base 12 following the typing of certain orders on the keyboard 22, prior to their execution by the head, to allow at base 12 to confirm the execution of the desired order. The logic specific to this dialogue will be described in support of Figure 4.

General information on the protocol

In general, the communication between head 11 and base 12 is done by sending messages (also called: "commands") from the head to the base and vice versa.

In this embodiment, the messages or commands are coded on bytes, defining function or data parameters, and, on the other hand, include agreed words indicating the start and the end of the message.

• les chiffres 0 à 9 et les lettres A à F , en caractères majuscules italiques soulignés représentent des chiffres hexadécimaux,
• les mots entre parenthèses et en lettres italiques soulignées représentent des octets. Il peut s'agit d'octets de données qui sont intitulés ci-après : (code de fonction), (données), (code de commande)., ( paramètres), (texte ASCII).
  Il peut également s'agir d'un octet de contrôle de parité : (parité).
  • les lettres X , Y ou Z en italiques soulignées, éventuellement indicées représentent des octets de données ou d'adresse dans les mémoires à accès direct.
  • les treize différents messages sont intitulés DC 0 , DC 1 , ... DC C
  
  A l'exception des messages d'erreur ou d'accusé réception, le format général des messages ou des commandes est :
      Fx , (données), (parité), FF
     où:

  Fx :

  est un octet de début de valeur comprise entre FO et FC, correspondant à chacun des messages ou commande DC 0 à DC C ,

  Données :

  ce sont un ou plusieurs octets qui véhiculent des informations telles que codes de commande ou de fonction et éventuellement le ou les paramètres nécessaires à l'exécution de la fonction sélectionnée.

  Parité :

  c'est un octet de parité qui est calculé avec un OU exclusif octet par octet sur l'ensemble du message.

  FF :

  est un octet qui marque la fin du message.

  
  Après envoi d'un message par la base ou la tête, le récepteur (la tête ou la base) attend l'octet de fin de message FF . Il en recalcule la parité. Deux cas peuvent alors se présenter :
  • le recalcul de la parité donne un résultat juste : le récepteur renvoie un accusé de réception composé des deux octets FD , FF ,
  • le recalcul de la parité donne un résultat faux : le récepteur renvoie un message d'erreur composé des deux octets FE , FF .
  
  Si au bout de 50 ms, le récepteur n'a pas renvoyé l'accusé de réception FD , FF ou le message d'erreur FE, FF , l'émetteur renverra à nouveau le même message (voir infra description figure 4). Au bout de trois tentatives infructueuses, un code erreur est affiché à l'initiative de la tête 11 sur l'afficheur 21, lorsque la tête n'a pas reçu d'accusé de réception ou de message d'erreur.
  Dans le cas où une émission tête vers base se fait en même temps qu'une émission base vers tête (collision), la procédure est la suivante :
• Côté base, l'émission vers la tête est interrompue.
• côté tête : si FF a déjà été envoyé, le tampon de réception est effacé. Une priorité à l'émission est ainsi conférée à la tête.

In the following description, the following conventions are used:

• the numbers 0 to 9 and the letters A to F , in underlined italic capital letters represent hexadecimal numbers,
• words in parentheses and in underlined italics represent bytes. These can be data bytes which are titled below: ( function code ) , ( data ) , ( command code )., ( Parameters ) , (ASCII text).
  It can also be a parity check byte: ( parity ).
  • the letters X , Y or Z in underlined italics, possibly subscripted represent bytes data or address in direct access memories.
  • the thirteen different messages are titled DC 0 , DC 1 , ... DC C
  
  With the exception of error or acknowledgment messages, the general format of messages or commands is:
  Fx , ( data ) , ( parity ) , FF
  or:

  Fx :

  is a start byte with a value between FO and FC, corresponding to each of the messages or command DC 0 to DC C ,

  Data :

  these are one or more bytes which convey information such as command or function codes and possibly the parameter or parameters necessary for the execution of the selected function.

  Parity :

  it is a parity byte which is calculated with an exclusive OR byte by byte over the whole message.

  FF :

  is a byte that marks the end of the message.

  
  After sending a message by the base or the head, the receiver (the head or the base) waits for the end of message FF . It recalculates the parity. Two cases can then arise:
  • the recalculation of the parity gives a fair result: the receiver sends back an acknowledgment of receipt composed of the two bytes FD , FF ,
  • the recalculation of the parity gives a false result: the receiver returns an error message made up of the two bytes FE , FF .
  
  If after 50 ms, the receiver has not returned the acknowledgment of receipt FD , FF or the error message FE, FF , the sender will send the same message again (see figure 4 below). After three unsuccessful attempts, an error code is displayed on the initiative of the head 11 on the display 21, when the head has not received an acknowledgment or error message.
  In the case where a head-to-base transmission is made at the same time as a base-to-head transmission (collision), the procedure is as follows:
• On the base side, transmission to the head is interrupted.
• head side: if FF has already been sent, the reception buffer is cleared. Priority to the program is thus given to the head.

List of messages : 1 °) Message DC 0

This message is sent exclusively from the base to the head. Its format is:
FO , (order code ), ( parity ), FF

The command code, on one byte, can take three values:
C0 : display of the word "ERR" + error code read in the head memory on the display
C1 : validation of the value to be franked, and installation of the printer.
C2 : authorization to start printing.

2 °) Message DC 1

a) When this message is sent from the base to the head, it transmits to the head display function codes such as for example tabulation.

Its format is then:
F1 , ( function code ), ( parameters ), ( parity ), FF

b) When this message is sent from the head to the base, it transmits the result of reading a register which has been designated by a DC 5 command (see below). Its format is then:
F1 , ( X ₁ ... X _n ) , ( parity ) , FF , where:
( X ₁ ... X _n ) : data recorded in the register designated by the DC 5 command.

3 °) Message DC 2

a) When sent by the base, it transmits the ASCII coded characters of the message to be displayed to the head display. Its format is:
F2 , ( ASCII text ) , ( parity ) , FF

b) When emitted by the head, it constitutes the mechanical and electronic initialization command. Its format is then:
F2 , (parity) , FF

4 °) Message DC 3

a) When sent by the base, it sends the mask for lighting the diodes associated with the keys on the keyboard (two bytes Z ₁, Z ₂ see appendix I). Its format is:
F3 , ( Z ₁, Z ₂), ( parity ) , FF

b) When sent by the head, it constitutes the postage acknowledgment message (postage made). Its format is:
F3 , (parity) , FF .

5 °) Message DC 4

a) When sent by the base, it transmits the keyboard mask to the head (two bytes Y ₁, Y ₂ see appendix II).
Its format is:
F4 , ( Y ₁, Y ₂), (parity) , FF

b) When sent by the head, it transmits the content of the keyboard buffer to the base (two bytes X ₁, X ₂ see annex II). Its format is:
F4 , (X ₁ , X ₂ ) , ( parity ) , FF .

6 °) Message DC 5

a) When sent by the base, it constitutes the command to read X bytes from the address Y of the direct access memory RAM of the head microprocessor (53). Its format is:
F5 , ( X , Y ) , ( parity ) , FF

b) When it is sent by the head, it reports the release of the last key pressed (when several keys have been pressed simultaneously, the last release causes the message to be sent). Its format is:
F5 , (parity) , FF .

7 °) Message DC 6

This message is exclusively sent by the base. It constitutes a command for writing X bytes from the address Y of the direct access memory RAM associated with the microprocessor 53 of the head; it should be noted that certain addresses are however protected against writing, such as for example postal registers. Its format is:
F6 , (X , Y) , (data to be recorded) , (parity) , FF .

8 °) Message DC 7

This message is exclusively sent by the base. It constitutes a command to rewrite the keyboard buffer, ie X bytes from the Y address. Its format is:
F7 , (X , Y) , (parity) , FF .

9 °) Message DC 8

This message is exclusively sent by the base. It constitutes a command for displaying the total credit contained in the permanent memory 70 of the head in which the state of the ascending counter is recorded. Its format is:
F8 , (parity) , FF

10 °) Message DC 9

This message is exclusively sent by the base. It constitutes a command for displaying the current postage value contained in the RAM memory associated with the microprocessor 50 of the head. Its format is:
F9 , (parity) , FF

11 °) Message DC A

This message is exclusively sent by the base. It constitutes a command which validates (in this case sets to one), in accordance with the mask constituted by the Y byte, the flag bits contained, at the address specified by the X byte, in the direct access memory RAM associated with the head. Its format is:
FA , (X , Y) , (parity) , FF

12 °) Message DC B

This message is exclusively sent by the base. It constitutes a command which invalidates (in this case sets to zero), in accordance with the mask constituted by the Y byte, the flag bits contained, at the address specified by the X byte, in the direct access memory RAM associated with the head. Its format is:
FB , (X , Y) , (parity) , FF

13 °) Message DC C

This message is sent by the base. It constitutes the command for erasing the display windows. Its format is:
FC , (parity) , FF .

Communication protocol from typing on the head keyboard

Figure 4 shows the sequence of operations from the input (100) of the keyboard keys and illustrates the communication protocol between the base and the head.

This protocol is implemented in programs recorded in microprocessors 50 and 53. These programs include in particular routines for receiving, preparing and transmitting messages, as well as subroutines for managing the serial communication means 51 and 54. These routines and these subroutines are in themselves within the reach of those skilled in the art, who may further implement the protocol described here on the basis of the indications which will follow. The program will not be annexed to this request for reasons of safety of the machines which will be manufactured and marketed after the filing of this request.

The microprocessor 50, located in the head, manages the keyboard 22, that is to say that in particular it detects all the keys as and when they are pressed (101); it prepares messages reporting the pressing of these keys (102) (see description of operation). These messages are transmitted (103) by the microprocessor 50 and then sent (104) by transmission means 51a that comprise the communication means 51 in the direction of the base via the serial link 17a-17b (step 104).

The message sent by the head is received by the reception means 54b of the base; the received message is first checked to determine if it is complete and does not contain a transmission error; to do this, the parity byte is recalculated (step 109) from the received message, and compared with the parity byte received in the message (test 110); if the recalculated parity and the transmitted parity are different, a transmission error message ( FE , FF ) is prepared (111, 109) then sent (106, 107) by the transmission means 54a to the head. If the parities are identical, an error-free acknowledgment message ( FD , FF ) is prepared (112, 108) then sent (106, 107) under the same conditions.

At the same time as the message was sent by the head, a time delay of 50 ms (113a) is started in the head; when this time has elapsed, a test (114a) is operated in the head, in order to determine whether a message acknowledgment of receipt without error ( FD , FF ) has indeed been received. If this is not so (115a), the initial message is again sent to the base; three attempts are thus made; if after these three attempts the message acknowledgment of receipt without error is still not received, an error code is displayed on the display 21 of the head, signifying that the system is not working, and that it is necessary to call the maintenance department.

When the message has been received and has given rise to an error-free acknowledgment, it is decoded (116) and its content is examined (test 117) to determine whether this message is addressed to the base, or whether it s is a message about the head. The conditions of this examination are entirely determined by the program of the microprocessor 53 of the base; it follows that the correspondence, which was given above, between the messages received from the head and the messages that the base sends back to it and their meaning, is only indicative. This correspondence can be modified by the only modification of the program of the microprocessor 53 of the base.

If the message received relates to a function of the head, one (or more) message (s) relating to the function is (are) prepared (s) (118-108) and then sent (s) (106-107) to the head for execution of the function. The message (s) are received by the reception means 51b. Control operations similar to those described above are then performed. The parity of the message is first of all recalculated (120). A test (121) is then carried out in order to determine whether the recalculated parity and the transmitted parity are different or not. If so, a transmission error message ( FE , FF ) is prepared (122-102) and then issued (103). If there is no error, an acknowledgment message ( FD , FF ) is prepared (123-102) and then sent. A time delay of 50 ms is started (113b) in the microprocessor of the base at each sending of message, a test (114b) is operated to determine if a message acknowledgment of receipt without error ( FD , FF ) has been successfully received. If this is not so (115b) the message is again sent to the head; three attempts are thus made.

After these three attempts, if they are unsuccessful, the transmission of a message from the base becomes impossible. Therefore, the next message from the head is no longer followed by an acknowledgment, an error message is displayed in accordance with the procedure described above.

Finally, if the message sent by the head was addressed to one of the functions managed by the base, for example distributing labels, or printing a line of a report or a report, the microprocessor 53 takes over this request (step 119).

In summary, the protocol described implements a bidirectional link system of the head and the base which provides very high security, and permanent control of its proper functioning.

It will be recalled here that the interpretation of the messages transmitted from the keyboard of the head and the return, by the base, of a message executable by the head are the fact of the software recorded in the microprocessor 53 of the base. This software can be modified. However, the software of the microprocessor 50 of the head is frozen once and for all, and is likely to understand only certain messages. The present invention therefore offers both flexibility, since the interpretation of messages sent by the head and the sending by the base of orders executable by the head, can be changed. However, the present invention presents at the same time an important security, since the structure of the messages understandable by the head is frozen once and for all, while the sensitive registers (for example the postal registers) cannot be modified by the messages transmitted from the base. Furthermore, it will also be observed that the meaning of the keys pressed on the keyboard of the head is determined by the base, which allows, by the simple modification of the software of the microprocessor 53 to reconfigure the keyboard.

Operation of the machine in "keyboard" mode

• en mode "clavier", c'est-à-dire dans un mode où les commandes et les données (notamment d'affranchissement) sont saisies sur le clavier 22,
• en mode "balance" où le clavier est partiellement inhibé et où les commandes et données d'affranchissement sont transmises à la base par un périphérique comportant une balance et un calculateur de taxes postales.

The machine described here is likely to work:

• in “keyboard” mode, that is to say in a mode where the commands and the data (in particular postage) are entered on the keyboard 22,
• in "balance" mode where the keyboard is partially inhibited and where the franking commands and data are transmitted to the base by a device comprising a balance and a postal charges calculator.

Hereinafter, the operation in "keyboard" mode will be described.

• un mode "normal" où le clavier est utilisé pour la saisie des commandes et des données d'affranchissement,
• des modes de "recharge" ou de "modification" où le clavier est utilisé par des utilisateurs habilités pour recharger la machine en fonds postaux et/ou modifier certaines caractéristiques.

It will also be noted that in certain variant embodiments the "keyboard" mode itself includes several operating modes:

• a "normal" mode where the keyboard is used for entering commands and postage data,
• "recharge" or "modification" modes where the keyboard is used by authorized users to recharge the machine with postal funds and / or modify certain characteristics.

In the first preferred embodiment first described below, the machine is only capable of operating in "normal" mode.

Each time a numeric key on the keyboard 22 is pressed, the keyboard buffer 59 is updated, and the code of the corresponding digit is put in the working area of the RAM of the microprocessor of the head; when the key is released, a DC 5 message is sent to the base microprocessor. When a function key is pressed, the keyboard buffer is updated and a DC 4 message is sent to the microprocessor 53 of the base. This message transmits the content of the keyboard buffer 59; this keyboard buffer will then be reset to zero before the base microprocessor accepts new keystrokes. Finally, when the key is released, a DC 5 message is sent to the base microprocessor.

The content of the keyboard buffer is analyzed by the microprocessor 53 of the base, so that it can determine its subsequent behavior. If the base needs additional information, it will send a DC 5 message to which the head will respond by DC 1 .

The base microprocessor will then first carry out the commands necessary to execute the mission defined by the function key contained in the keyboard buffer, (for example actuating the label dispenser, displaying a message on the screen using the DC 1 and DC 2 messages, modify the keypad buffer to inhibit certain keys and activate others, send the head an order to validate the value to be franked by a DC 1 message, or any other action determined by the function code received and the base microprocessor program). Then it will send, secondly, a DC 6 message to reset the keyboard buffer.

It should be noted here that it is in the program of the microprocessor of the base that are the instructions executed to the recognition of a mask received from the keyboard; which means that it's the microprocessor of the base which decides the meaning of a key on the head keyboard, and which can possibly give a single key several effects at different times during the course of the program. The described method therefore makes it possible, by modifying only the signs marking the keys, and without modifying in any way the head, but by modifying only the program of the base, to change the assignment and / or the role of the keys of said keyboard ; it is thus possible to create new combinations of functions in the head, obtained by combining the elementary functions available in the head and which can be called from the base.

It will further be observed that in the "normal" operating mode of the machine described here, no function command in relation to the franking, entered on the keyboard 22 can be executed without this command having passed through the base, which is favorable for the possible reconfiguration of the keyboard and the addition of new functions by the only modification of the base, and also confers a good security on the franking machine since the structure of the commands understandable by the microprocessor of the head is fixed a once and for all in the hidden software of the head microprocessor 50.

As a variant, the operation described above can be substantially modified in the following way: each time a digital key is released, on reception of the resulting DC 5 message, the base microprocessor can intervene to read in the working memory the code of the digit, and use it as it pleases: for example, memorize this code to capture the sequence of numbers typed on the keyboard and interpret the combination, or even replace in the working memory of the head the code in question by another code, which allows you to redesign the keys on the numeric keyboard.

In a second preferred embodiment, all the data entered on the keyboard is not relayed by the base, provided that it does not concern the security of the franking function: for example, the transfer of the value of the numbers typed with the keyboard in the working memory, and the transfer of the imprint offset values are also transferred directly from the working register to the imprint offset register, when the FOOTPRINT key is pressed. But in these two cases, thanks to the messages sent when the keys are released, and to the messages transmitting the content of the keyboard buffer, the base microprocessor is informed and can always reconstitute the control actions performed; it is therefore possible for the base to intervene by sending messages aimed at prohibiting, or modifying these commands, and reporting on the head display.

In the second preferred embodiment, the machine is capable of operating in "recharge" mode and, for this purpose, there are still other commands which are executed directly in the module, without the microprocessor of the base being able to be informed and able to intervene: these are the commands concerning the reloading of the credit register of the franking machine by the personnel authorized to do so, or by using procedures suitable for restricting access to it: for example, access to a such reloading may involve the use of a secret code; the secret code, struck on the head keyboard is recognized by the microprocessor 50 and does not cause any message to be sent; Likewise, the data then typed on the keyboard to reload the down counter, once authorization has been received or after using an access key, also does not cause a report message at the base.

In this second preferred embodiment, the protocol described in support of FIG. 4 is substantially modified. The modifications are shown in dashed lines. After the step (101) of detecting the keys pressed, a test (131) is carried out in order to determine whether the key or the combination of keys pressed are preferred (that is to say that they correspond to the orders executable directly by the head, without transit through the base for example: recognition of the access code in "reload" mode). If so, the microprocessor 50 controls the execution (132) of such orders (for example switching to "reload" mode). If not, the message preparation step (102) can be performed as described above. A test (133) can also be provided to prevent reporting at the base of certain orders executable by the head (in "reload" mode). For the rest the protocol is unchanged.

Operation of the machine in "balance" mode

• un message DC A pour valider dans la zone 73 de la RAM de la tête, le drapeau autorisant le déclenchement de l'impression,
• un message DC 3 pour allumer la diode luminescente associée à la touche "BALANCE",
• un message DC 4 pour transmettre au module un masque clavier chargé d'inhiber certaines touches, la touche "BALANCE" exceptée ;

In the two preferred embodiments, the machine can operate without using the keyboard: this is for example the mode of operation of the machine in coupling with a device consisting of a balance provided with a tax calculator. Such a device is well known to those skilled in the art. To put the machine in "balance" mode, the operator presses a key designated "BALANCE" on the keyboard, which has the effect of sending a DC 4 message transmitting the keyboard mask to the base, which allows the microprocessor 53 from the base to identify the key designated "BALANCE". The microprocessor 53 of the base then sends back:

• a DC A message to validate in area 73 of the RAM of the head, the flag authorizing the triggering of printing,
• a DC 3 message to light the light-emitting diode associated with the "BALANCE" key,
• a DC 4 message to transmit to the module a keyboard mask responsible for inhibiting certain keys, except for the "BALANCE"key;

Consequently, and as long as the "BALANCE" key has not been pressed a second time to return to the "keyboard" mode, the microprocessor 53 of the base takes control of the printing register of the head, by DC messages 6 , and of the display 21, by messages DC 1 and DC 2 ; and the microprocessor 53 of the base also sends DC 0 messages to cause the printer to automatically adjust to the tariff indications received by the device constituted by the scale and its tax calculator.

Of course, the present invention is in no way limited to the embodiments chosen and shown, but on the contrary encompasses all variants within the reach of ordinary skill in the art.

APPENDIX I: MASK OF THE DIODES

   z_1i = bit de l'octet Z ₁
   z_2i = bit de l'octet Z ₂
   si z_1i = z_2i = 0 diode éteinte
   si z_1i = z_2i 1 diode allumée
   si z_1i < > z_2i diode clignotanteIn this example, to manage six diodes associated with six keys, the mask is organized as follows:

z _1i = byte bit Z ₁
z _2i = byte bit Z ₂
if z _1i = z _2i = 0 LED off
if z _1i = z _2i 1 LED on
if z _1i <> z _2i flashing diode

APPENDIX II: MASK AND KEYBOARD PAD

   x_1i = bit de l'octet X ₁
   x_2i = bit de l'octet X ₂
   x_1i ou x_2i = 1 touche enfoncée
   x_1i ou x_2i = 0 touche non enfoncée
   y_1i = bit de l'octet Y ₁
   y_2i = bit de l'octet Y ₂
   y_1i ou y_2i = 1 touche autorisée
   y_1i ou y_2i = 0 touche inhibéeIn the preferred embodiment, to manage a keyboard having 10 undifferentiated numeric keys and 12 function keys, the keyboard buffer is organized (2 bytes X ₁, X ₂) and the validation mask (2 bytes Y ₁, Y ₂) as follows :

x _1i = bit of byte X ₁
x _2i = bit of byte X ₂
x _1i or x _2i = 1 key pressed
x _1i or x _2i = 0 key not pressed
y _1i = byte bit Y ₁
y _2i = byte bit Y ₂
y _1i or y _2i = 1 authorized key
y _1i or y _2i = 0 key disabled

Claims (13)

Franking machine comprising in particular a first part (11) called "head" and a second part (12) called "base", a keyboard (22) and a display (21) associated with the first part, and means of communication ( 51, 54; 17a, 17b) connecting these two parts, the head (11) comprising a first microprocessor (50) arranged to manage a printing means and a memory of which certain registers are assigned to the management of postal data, such so that the postal data can only be modified to record the postage actually printed by the printing means, and that the printing means cannot print postage without these postage being counted by modifying the postal data in certain at less of said registers; the first microprocessor (50) further managing the keyboard and the display as well as the part (51) of said communication means intended to transmit messages to the base (12) and to receive messages from the latter, the base comprising a second microprocessor (53) arranged so that it manages communication means (54) intended to transmit and receive messages to or from the head (11), machine characterized in that the first (50) and second (53) microprocessors implement, in a so-called "normal" operating mode, a communication protocol suitable for transmitting to the base messages representative of at least some of the commands entered on the keyboard (22) and for retransmitting from the base towards the head the commands executable by the latter, so that from the keyboard (22) of the head one cannot control at least certain functions, without the commands relating to such functions do not pass through the base (12). Franking machine comprising in particular a first part (11) called "head" and a second part (12) called "base", a keyboard (22) and a display (21) associated with the first part, and means (51, 54; 17a, 17b) of communication connecting these two parts; the head (11) comprising a first microprocessor (50) arranged to manage a printing means and a memory of which certain registers are assigned to the management of postal data, so that the postal data can only be modified to save the postage actually printed by the printing means, and the printing means cannot print postage without these postage being accounted for by modifying the postal data in at least some of said registers, this microprocessor further managing the keyboard (22 ), the display (21) associated with said head as well as the part of said communication means associated with the head and intended to transmit (51a), respectively receive (51b), messages to, respectively from, the base (12) , the latter comprising a second microprocessor (53) arranged so that it manages the part of said communication means associated with the base and of is designed to transmit, respectively receive, messages to, respectively from the head (11), machine characterized in that, on the one hand, said first microprocessor (50) is arranged so that, in a mode of operation called " normal ", it identifies the key (s) struck (101), and transmits (103) to the base by said communication means (51), one or more messages representative of the identification, while, on the other hand, said second microprocessor is arranged to interpret the messages received (116), and to transmit (118, 108, 106), through said communication means, one or more messages representative of orders executable by the first microprocessor, so that '' from the head keyboard it is not possible, in said normal operating mode, to control any function at least in relation to postage, without that the control of these functions does not pass through the base (12). Franking machine according to claim 1, characterized in that the head (11) also includes in its program memory instructions enabling it to detect codes relating to keys or combinations of keys received from the keyboard (22) corresponding to executable orders by the microprocessor (50) of the head (11), the program providing that in the event of recognition of a combination relating to an order executable by said first microprocessor, this order is executed (132). Machine according to any one of claims 1, 2 or 3, characterized in that the microprocessor of the head (11) stores, in an area of its associated memory called the keyboard buffer, and keeps up to date, a binary word identifying all the non-numeric keys that have been pressed since the last command to erase this binary word. Machine according to claim 4, wherein said binary word also identifies the pressing of at least one numeric key. Machine according to any one of claims 4, 5, characterized in that the program of the head microprocessor (11) includes instructions so that any pressing of certain non-numeric keys on the keyboard (22) of the head (11) causes a message to be sent by the communication means, this message transmitting said binary word to the base (12). Machine according to any one of Claims 4 to 6, characterized in that the program of the microprocessor (53) of the base (12) includes instructions enabling it to identify the non-numeric key (s) possibly contained in the messages received, such identification then sending a message to erase said binary word in the memory associated with the head microprocessor (11). Machine according to any one of Claims 4 to 7, characterized in that the program of the base microprocessor (12) includes instructions enabling it to identify, among the non-numeric keys defined by the binary word received, that which has was struck last and caused the message to be sent. Machine according to claim 8, characterized in that the program of the base microprocessor (12) includes instructions assigning said non-numeric key last struck a precise meaning. Machine according to any one of Claims 1 to 9, characterized in that some of the messages relating to the keyboard (22) are messages which have the purpose of inhibiting or activating certain keys. Machine according to any one of claims 1 to 10, characterized in that certain messages concerning the memory associated with the microprocessor of the head (11) are messages controlling the reading of an area of said memory, specified inside these messages, and ordering the sending of a return message containing this data read. Machine according to any one of claims 1 to 11, characterized in that certain messages concerning the memory associated with the microprocessor of the head (11) are messages ordering the writing of specified data at the specified addresses of said memory, the addresses comprising sensitive data which cannot be specified by means of instructions from the base microprocessor program (12). Machine according to any one of Claims 1 to 12, characterized in that the program of the head microprocessor (11) is provided with instructions prohibiting the execution of write messages at addresses containing sensitive data.

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