Interfacing Single-Board Microcomputer Controls to Conventional Controls for an Environmental Control System
Bailey W. Mitchell · Transactions of the ASAE · 1984
ABSTRACT Amicrocomputer-based control system was designed and interfaced to a conventional solid-state control system to provide improved and more flexible control. The new system provided on-line digital signal conditioning; remote monitoring, recording, and setpoint adjustment; capability of running fixed, step, or cyclic conditions; and integrated control of all the controlled devices as well as some large external components. Experiments using cyclic conditions were conducted over a period of several months, and control errors were found to average less than 0.5 C for dry-bulb temperature and less than 1.0 C for dewpoint temperature. The new system provided many more capabilities than the previous conventional system.