This module is responsible for controlling a two-position heating valve within a zone control application. This module determines the required percent of capacity and then provides the appropriate control input to an MSC. This module also provides for discharge air low limit control in Unit Ventilator applications.
The module accepts as inputs a mode, process variable, setpoint, low limit process variable, low limit setpoint, and other configuration inputs. The module outputs a representative percent command, a percent request, a control status, and other outputs which feed the MSC module. It passes the outputs to the MSC module that controls the actual binary outputs. This module also incorporates tracking the overridden value of the actual output object (AO, PAO). The module resets the PIDs to default tuning parameters if the Reset PID Tuning input is not Normal.
This module provides EWMA diagnostic values calculated by the PID. Controllers have the ability to collect data about their inputs, outputs, and internally calculated variables. Inside the controller, the EWMA minimizes memory requirements, reduces communication traffic, and provides an easy way to analyze collected data. See EWMA Diagnostics in the Commissioning a System section for more information.