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Off: Set the Percent Cmd to 0% and the Instant Shutdown output to False. The MSC turns off all outputs, but only after all timers are satisfied.
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Max: The Percent Cmd is set to 100%. This value then feeds through the MSC and the stages are turned on accordingly based on the timer settings.
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Limited Max: Set the output to the limited max value. This value then feeds through the MSC and the stages are turned on accordingly based on the timer settings.
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Hold: Hold the Percent Command output at the 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 because 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 Cooling Percent Cmd.
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Instant Shutdown: Set the Percent Cmd to 0% and the Instant Shutdown output to True. The MSC turns off all outputs instantly.
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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 .
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Failsoft: Set the output to the Failsoft value. This value then feeds through the MSC and the stages are turned on accordingly based on the timer settings.
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Proof of Airflow: When set to False or Fault, sets the output to zero and sets the Instant Shutdown output to True. Typically used to prevent electric heating or DX cooling from being enabled without airflow. When set to True, this allows the output to vary and sets the Instant Shutdown output to False.
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Unreliable Process Variable: If the process variable is not Reliable and the module happens to be commanded to Control, the PID holds its last value. Typically, the state generator provides an alternate mode (for example, Hold or Off) when the process variable is not Reliable.