Abstract: A line driver system for digital communication, using logic-level voltages, between an electronic transmitter-receiver device and an electronic receiver device, such as between a computer and a typewriter, a line printer or a cathode ray tube, has the transmitter-receiver device at a location remote from the receiver device. An output of the transmitter-receiver device is electronically coupled to an input of the receiver device using one line of a communications bus. This output of the transmitter-receiver device is coupled to that line of the bus through an optical isolator and then through a power booster. The receiver device has an output that provides a voltage signal when the receiver device is switched on-line. This voltage signal is provided at that output of the receiver device when the receiver device is capable of transforming digital information, that is provided at its input, to a readable form that is printed or displayed by the receiver device.

Abstract: During the use of process equipment it is necessary to position control valves, change analog set-point signals for process controllers, move thermocouples to specific positions in thermowells, etc. A computer control system for these operations utilizes binary information on three sets of bits of a bus and an execute signal on another bit provided by a computer, usually at a remote area, to select the device of the equipment to be changed and to make the change. The system includes: an information interface card; a number of actuator module cards; decoder/demultiplexer means; and device select means. The interface card is connectable to first and second sets of bits of a bus that is connectable to additional systems. The device select means is connected to a third set of bits of the bus. The binary information to the device select means results in a signal only at one of its outputs, each output being connected to a different system.

Abstract: The system includes: a number of subassemblies, each containing a set of switches connectable at their pair of inputs to different sources of analog signals and containing a multiplexer/decoder having outputs connected to different switches for their selective actuation; a differential amplifier having a pair of inputs connected to the pair of outputs of all of the switches; analog/digital converter means having its input connected to the output of the amplifier and having outputs providing multi-bit digital information; and control means that provides various functions.

Abstract: At the general area of a set of BCD counter means, each to contain individual accumulated counts, a system, called a multi-counter register, is generally located for its use that permits the individual reading of the counter means in a selective mode by local readout means at the general area or by a computer at a remote area by the use of a small number of address channels extending from the location of the counter means to the computer.