Form A relay digital output:
Form A digital output means that, outputs are normally open contacts with one common terminal (C) and one normally open terminal (NO). The terminals are isolated from signal ground.
Form A digital output internal configuration in DO-FA-12 and DO-FA-12-H I/O modules, for AS-P
Form A digital output internal configuration in AS-B and MP-Cs
Form C relay digital output:
The Form C digital outputs are switching contacts with one common terminal (C), one normally open terminal (NO), and one normally closed terminal (NC). The terminals are isolated from signal ground.
Form C digital output internal configuration in DO-FC-8, DO-FC-8-H, UI-8/DO-FC-4, and UI-8/DO-FC-4-H I/O modules, for AS-P