Читать книгу Automation of Water Resource Recovery Facilities - Water Environment Federation - Страница 168

Design engineers should describe any local equipment controls and detail their relationship and interactions with the PLC or supervisory control and data acquisition system. This information is especially important to ensure compatibility among all the engineering disciplines involved. Local and remote switches, e-Stops, hardware interlocks, relay logic, and single-loop controllers inform operations of the level of local control available and identify controls and functions that are done outside of the PLC for programmers. Programmers can use this information to suppress nuisance alarms from the PLC. The description of local controls should identify any safety or software permissives and interlocks that are bypassed in local control operations.