摘要 |
A bus programmable slave module card 30 for use in a computer control system which comprises a master computer and one or more slave computer modules interfacing therewith by means of a bus and wherein each slave module includes its own microprocessor memory, and control program for acting as a single loop controller. The slave card includes a plurality of memory means corresponding to a like plurality of memory devices in the master computer, for each slave memory means its own communication lines connectable through the bus with memory communication lines of an associated memory device in the master computer, and a one-way electronic door which is switchable to either a closed condition or a one-way open condition. With the door closed, communication lines between master computer memory and slave memory are blocked. In the one-way open condition invention, the memory communication lines of each slave memory means connect with the memory communication lines of its associated memory device in the master computer, and the memory devices of the master computer and slave card are electrically parallel such that information seen by the master's memory is also seen by the slave's memory. The slave card is also connectable to a switch for electronically removing the slave microprocessor (45) from the system.
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