- #1
Femme_physics
Gold Member
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Hey guys, I'm trying to wrap my head around this electronic schematics of a PLC, because I've started ladder-programming it. Can anyone explain to me why are there TWO diodes before the transistor? I get that one diode shows an "active" or "inactive" state when it's turned on or not. But why the other diode before the transistor?
Attached is an image of the sketch as well as the entire PDF with the PLC specifications
Attached is an image of the sketch as well as the entire PDF with the PLC specifications