Remote signalling system and method

Abstract

Abstract 1414574 Automatic exchange systems; wired broadcasting AMP Inc 31 Jan 1973 4920/73 Headings H4K and H4R [Also in Division G4] A communication system comprises a two conductor transmission line to which is connected; a master clock unit adapted to transmit over the path, frame synchronizing pulses separated by trains of time slot defining pulses, each time slot being defined by start and stop pulses of current at different potentials; a transmit unit adapted to insert an information signal between the start and stop pulses of a preselected time slot and a receive unit adapted to extract an information signal from such a slot. The information may be analog data transmitted in pulse width form or digital data in binary form. As described the system is mounted on a vehicle and includes a master station at which is located the master clock, a stereo unit 44 with two transmitters 46, 48 and an array of control buttons 40 and transmitter 42. A computer 32 is also coupled to the line 12 by a transmitter 36 and receiver 34. The stations may include lamps 16 controlled by receivers 18 and speakers 22 with which are associated on/off switches 26 and selectors 28. The master clock unit (Fig. 4, not shown) generates a long synchronizing pulse of "1" potential followed by a short pulse of 0 potential then a chain of time slot start and stop elements of "1" and "0" potential each separated by an intervening period in which the master clock unit drives the line to one potential or the other depending on the direction in which the line is being driven by a transmitting unit. Fig. 5 shows a transmitter station. The equipment shown in upper portion of the diagram is provided at every station and includes a threshold detector (Transistors Q22-Q24 and Zener 22) which steps a time slot counter 80 and feeds a single shot circuit (Q25-Q26) which responds to the long duration of a synchronzing pulse and resets the counter to zero. The counter steps for each start pulse and at every time slot except that associated with that transmitter station enables a transistor Q30 preventing a transistor Q31 from conducting. During the allotted time slot transistor Q31 conducts or not depending on whether the data bit as set by switch DS is "0" or "1" or conducts for a portion of the time slot characteristic of an analog input at 87 if switch DS is set to the analog position 86. It is stated that more than one station may use a single time slot, the signals being combined in OR gates and that in this case the switches S also have a centre position.

Inventors

No inventors recorded.

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