Attributes (Cooling Tower PID Control v61) - Johnson Controls - Metasys - LIT-12011147 - Software Application - Controller Configuration Tool - 15.0

Control Status

V

This output indicates the current status of the cooling tower PID.

Deadband

This is the value used to prevent the PID from overreacting when the process variable is near the setpoint.

Fan Type

This input indicates the type of fans controlled by the central cooling plant. This module supports variable speed fans, 1-speed fans, 2-speed fans, 3-speed fans, and vernier control.

Integral Time

This input is the Integral Time used by the cooling tower PID controller.

Limited Max Value

Defines the proportional output 0% when the module is in Limited Max mode.

Min Speed

This value is the minimum output for the Percent Cmd when VFD Fan is true. This value is the minimum speed at which the fan runs.

Mode

This input indicates the desired operating mode for the cooling tower PID.

Number Available

This input indicates the number of cooling towers that are enabled.

Number Of Towers

This input indicates the number of cooling towers in the central plant.

Offset

This input is the value for Percent Cmd when the error is zero. The output can vary from this value if the cooling tower PID had to integrate for some time to drive the Process Variable to the Setpoint.

Percent Cmd

V

This modulating signal is used to drive variable speed fan drives.

Process Variable

This input is the value that is controlled by modulating the Percent Cmd output.

Proportional Band

This input is the Proportional Band used by the cooling tower PID controller.

Setpoint

This is the setpoint that the cooling tower PID attempts to control the Process Variable to.