| 摘要 |
Radio-link data capture system between a computer and several automatic distribution machines. It comprises a central apparatus, comprising a personal computer running under the MS-DOS system provided with at least one RS-232 communications port and printer. To the communications port is connected the special AR-5HH modem, whose mission consists, in addition to modulating and demodulating the RS-232 signals, of decoding the characters which it receives from the computer and triggering the following actions: ESCAPE character: Simulates the PTT key in radio (Push to talk). Any other control character releases the PTT key. All the characters received via radio, once demodulated, are transmitted to the computer. As can be seen in the protocol described below, this operational mode ensures the correct functioning of the said protocol except in relation to time delays, control of which depends on the service program of the computer. In each automatic distribution machine there will be installed an AR-5H1 control device which includes the modem and the logic required to interrogate the Executive 1900 coin collection device and to respond appropriately to interrogation messages from the computer. It is provided with a powerful microprocessor which incorporates the logical functions of message decoding, processing of data from the coin collection device and the characteristic processes of modulation and demodulation of the radio signals. <IMAGE>
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