Applications of Distributed Microprocessors in the CESR Control System

Intelligent microprocessor based interfaces are used to relieve the main control computers of time consuming tasks requiring real-time response. The basic system consists of a Zilog Z80 CPU, CESR control system interface, read-only and read-write memory, and input/output address decode circuitry. One application employs inexpensive potentiometers to provide a cost effective operator-machine interface with excellent response. It uses a 64 channel analog-to-digital converter to scan 30 two-gang potentiometers, calculating the change in position of each knob 60 times a second. A second application uses multiprogramming techniques to achieve separate position setting of ten motorcontrolled devices with adaptive feedback. The controller can accept high-level commands to let the microprocessor guide the device to its destination, or low-level commands to let the main computer retain complete control of the device. Applications include RF phase-shifters and attenuators, and motor-driven variacs.