Thats the problem I haven't used a variac and would just like to find an overview of how they work or how to use them---I know it is a Staco and it has 3 internal motors that are controled to produce the power to 5 motors we are using. I know I need to check the voltage to make sure all three phases are good if not set a fault flag and disable the staco. There is an increase and decrease to phase a, b, c of the variac. I know this is confusing cause I got this project after someone else setup all the i/o cards etc. for AB PLC5 now I have to figure out all these i/o and send it to the variac.
I can tell you I have been given an output & input bit from each motor we are sending power to via variac, and an increase/decrease bit for each phase of the variac (phase a,b,c). I also have blk transfers from 1771 nt1 cards sending me amps from phase a,b,c & volts from a,b,c & a watt reading---from each of the motors we are powering.
Does any of this make sense to you??