What are the differences between the PID function included in the Script editor library and bPID as traditionally used with Continuum?

Issue

Why does the PID example function in the Script editor library not operate like the bPID?

Product Line

Andover Continuum, SmartStruxure Solution

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 Lessons Learned article #5327

 

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.