slc75

thanks alot for the reply. i believe i will try the diode. i wonder if i could hook them directly to the modules?

i have a machine with these and they control several dc coils for hydraulic valves. problem is that they keep frying the i/o modules. i figured that it must be because of kickback from the collapsing field when the coils deenergize. i wonder if anyone had any suggestions how to remedy this problem- i'm thinking maybe a diode? thanks