A telephone data terminal and data collection network for communicating data over a telephone system using DTMF tone dialing. A telephone data terminal (10) includes an optical bar code reader wand (16) and a slot (22) in which a magnetic field sensor is disposed for reading variations in magnetic field...http://www.google.fr/patents/US4897865?utm_source=gb-gplus-shareBrevet US4897865 - Telephone data collection device
