Issue
Why does the PID example function in the Script editor library not operate like the bPID?
Product Line
Andover Continuum, EcoStruxure Building Operation
Environment
Script/ Plain English differences
Cause
PID example does not operate as expected with regard to the integral action.
Resolution
The Script Program editor contains various library functions that can be selected from the "Library" tab at the lower right of the editor screen.
Plain English program/ function examples were available and used in Continuum and known as the "Andover Controls Standard Modules" ACSM, they are available in Where can I obtain standard Plain English example functions?
This document also contains further information about the PID use and application.
In both the script PIDLoop (Long version) library function and the bPID function as used in Andover Continuum the Proportional component is the same, they both use Proportional Gain which is defined as 1 / Proportional Band.
In the Script Editor Library PID function this requires the Integral Gain constant, this is defined as 1 / Integral Action Time as used in the Continuum bPID function.
In the Script Editor Library PID function this requires the Derivative Gain constant, this is defined as 1 / Derivative Action Time as used in the Continuum bPID function.
Either of the functions may be used in the SmartStruxure Script editor, but you need to ensure your calling program is passing the correct arguments for the PID function used.
