Primary States (Heating Staged Outputs with DA-T Low Limit) - Johnson Controls - Metasys - LIT-12011147 - Software Application - Controller Configuration Tool - 13.1

Controller Tool Help

Brand
Johnson Controls
Metasys
Product name
Controller Configuration Tool
Document type
User Guide
Document number
LIT-12011147
Version
13.1
Revision date
2019-12-04
Language
English
  • Off: Sets the Percent Cmd to 0% and sets the Instant Shutdown output to False. The MSC turns all outputs off, but only after all timers are satisfied.

  • Max: The Percent Cmd is set to 100%. This value then feeds through the MSC and the stages turns on accordingly based on the timer settings.

  • Limited Max: Set the output to the limited max value. This value then feeds through the MSC and the stages turns on accordingly based on the timer settings.

  • Hold: Hold the Percent Command output at it’s current value. This value continues to feed to the MSC and the stages continue to be controlled by the sequencer. Should timers expire, it is possible for the number of enabled stages to change during a hold command since the Percent Command is really the only value that is explicitly held. If the Output Overridden is true, then the Output Position input is passed to the Heating Percent Cmd.

  • Instant Shutdown: Sets the Percent Cmd to 0% and sets the Instant Shutdown output to True. The MSC turns off all outputs instantly.

  • Control: Adjust the output to control the Process Variable. As this Percent Cmd varies, it causes changes to the enabling of the staged outputs from the MSC. If the input PID Tuning Reset is true, the Reset Tuning input to the PID is set to true causing the PID to recalculate its tuning parameters. While that occurs, the Heating Percent Cmd is held at its last value.

  • Control Limit: Adjust the output to control the Low Limit Process Variable. As this Percent Cmd varies, it causes changes to the enabling of the staged outputs from the MSC.

  • Failsoft: Set the output to the Failsoft value.

Table 1. Heating Staged Outputs with DA-T Low Limit Command Hierarchy

Proof of Airflow

Mode

PID Tuning Reset

State

Fault

*

*

Instant Shutdown

NOT Fault

Instant Shutdown

*

Instant Shutdown

NOT Fault

Off

*

Off

NOT Fault

Limited Max

*

Limited Max

NOT Fault

Max

*

Max

NOT Fault

Hold

Reset 1st PID

Control Limit

NOT Fault

Hold

*

Hold

NOT Fault

Control

*

Control

NOT Fault

Control Limit

*

Control Limit

NOT Fault

Failsoft

*

Failsoft