Cascaded Discharge Air Setpoint Determination v51 - Johnson Controls - Metasys - LIT-12011147 - Software Application - Controller Configuration Tool - 15.0

Controller Tool Help

Johnson Controls
Product name
Controller Configuration Tool
Document type
User Guide
Document number
Revision date
Important: As of Release 5.1, the Cascaded Discharge Air Setpoint Determination v51 module replaces the Cascaded Discharge Air Setpoint Determination v50 module.

This module resets the discharge air temperature setpoint based on the zone temperature error. This module should only be used when the air handler is controlling one zone. The module has inputs for the control temperature, heating and cooling setpoints, PID configuration inputs, and min and max heating and cooling DAT setpoints. The module may operate in one of several modes which include Off, Hold, Htg DA-Tsp Reset, or Clg DA-Tsp Reset. This module has outputs for the DA-T setpoint. This module resets the PIDs to default tuning parameters if the Reset PID Tuning input is true.

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.

This module also provides a quick transition from heating to cooling mode during major changes to space load conditions or setpoints (for example, a large group of people enter a space, or a schedule changes from unoccupied to occupied mode).

Figure 1. Cascaded DA-T Setpoint