How to wire a Sherline 8700 controller to a PMDX-122 for 4th Axis in Mach3?

[NavyHk]

Hello everyone. I have been using a PMDX-122 board with three Gecko 203V drivers in Mach3, and I am looking to add a 4th Axis with my Sherline 8700 controller in slave mode. Normally, I would connect the step, direction, and ground from my 203v drivers to the 122 board.

Would I need to connect the 8700 controller in the same way as the 203V's, or just need to connect the step and direction only? Just making sure that I don't damage the 122 board or the 8700 controller by plug and pray. Thanks.

[12strings]

This is the 8700 indexer, right?  You will need the ground connection from the PMDX-122 to the 8700 DIN connector.  That is the return path for the signals going into the step & direction pins.  No return path, no electron flow, no signals.