I am using a PMDX-416 board, Mach4 version 4.2.0.5036, and SmartBOBUSB plugin 0.53.283. I am using screen set WX4.

Input and output signals are defined like this:

Input   Active Low    Motor 0 Home   SmartBOBUSB/Pin11
Input   Active Low    Motor 1 Home   SmartBOBUSB/Pin12
Input   Active Low    Motor 2 Home   SmartBOBUSB/Pin13
Input   Active Low    Motor 0 ++   SmartBOBUSB/Pin11
Input   Active Low    Motor 1 ++   SmartBOBUSB/Pin12
Input   Active Low    Motor 2 ++   SmartBOBUSB/Pin13
Input   Active Low    PROBE   SmartBOBUSB/PinC
Input   Active High    E-Stop   SmartBOBUSB/Pin10_EStop
Output   Active High    X Home   SmartBOBUSB/Pin14
Output   Active High    Y Home   SmartBOBUSB/Pin16
Output   Active High    Z Home   SmartBOBUSB/Pin17
Output   Active High    Spindle On   SmartBOBUSB/Relay
Output   Active High    Coolant On   SmartBOBUSB/Pin1

X, Y, and Z motion works. I can write a program and machine a part. The spindle turns on with M3 and off with M5. Coolant (an add-on relay) turns on with M8 and off with M9. I can home all axes to 0. E-stop works.

But when I try to use TOUCH or PROBING, I have problems. I have two leads for the touch function, one going to PinC and a clip I put on the spindle. The other goes to a brass disk that is my touch surface, and to GND.

If I select the TOUCH button, fill in the values for touchpad thickness, retract distance, etc., and click on the button to locate Z, the spindle moves down, touches the bras disk, changes the Z value to the thickness of the disk minus a few thousands for overrun, and stops. The spindle does not retract. The "Selected Probe is Currently Active" button is lit.

If I select the PROBING button, the screens come up, but basically nothing works.

So what am I doing  wrong, if anything?