Barber Colman OEM'd the main logic board from Control Pak and put them in their own box.
Barber Colman's QC engineers were hard core SOB's and they put that system through the wringer, trying to break it in a million ways. They had a special smile when they had found another bug or a screw terminal they could zap with a spark generator and lock the system up. They were unhappy when they could not break it anymore. That's why there are still some Supervisors running today. They are tough as nails. I owe those guys a lot.