This is my first time posting in a forum. I have been using Mach2 for several months on my gantry plasma machine. I just bought THC300 from Bob Campbell and I have setting it up. That's when I discovered my limit switches were not working. I'm using a Fet4 from Stepperworld. The Fet4 has lugs to hook switches to. One ground and four for different axises. I put a volt ohms meter across the ground and switch lug with the power supply off, I got about 2.4 volts. With the power supply on, I got around 5 volts, Does this sound right? Should I be picking up anything with the power supply off? Will this afect weather it is active high or low?