PID loops have variables and functions that allow programmatic access to the loop. Most of the variables match up with parameters available from the PID loop. All variables and functions start with PID.PIDName. or ConnectionName.PID.PIDName. where PIDName is the name of the PID loop you wish to work with.
P : numeric
I : numeric
IntSum : numeric. This is the current accumulated sum from the integral term. This is read/write so you can change the value externally and the PID loop will update the sum from that point
D : numeric
SPMax : numeric
SPMin : numeric
OutMax : numeric
OutMin : numeric
ReverseActing : 0 or 1
LoopInterval : numeric in seconds
HistoryLength : numeric. This determines the number of points kept in the PV, SP, and OV histories. The default is 3600. If you don't need these histories, you may want to set this parameter to 1. In addition to programmatic access, the histories are used to generate the PID view graphs.
AutoTune_P: read only numeric result of the autotune
AutoTune_D: read only numeric result of the autotune
AutoTune_I: read only numeric result of the autotune
StartAutoTune(height): starts up the autotune procedure with the given relay height. Height must be non-zero.
StopAutoTune(): stops the current autotune procedure if running. Throws an error if the autotune is not running.
PVHistory: an array with the history of process variable values with time. Use subset notation to pull parts of this array: PVHistory[0]
SPHistory: same for set point
OVHistory: same for the output variable
