M700 Ext. Estop Code - No Movement

Hello, I’m having an issue with my Stepcraft M700 that is running a UC400ETH motion controller.

Whenever I try to jog any axis, the machine immediately throws:
“Ext. E-Stop Triggered”
and the reset button starts flashing. I can hear a small “tick” from the machine each time I press a jog direction, but there is no movement. To clear the error, I have to physically press my E-stop down and release it again.

A few notes:

• The machine is not sitting on any limit switches.

• UCCNC does not show any limits as active.

• Homing produces the exact same result: instant Ext. E-Stop.

• UC400ETH is connected, blue LED on, and UCCNC recognizes the controller.

• Reset clears normally until I attempt any motion.

• All wiring appears factory-connected — no modifications.

• Diagnostics page indicates: 
  • O2 - Red
  • I13 - Green
  • I15 - Green
  • A home - Green
  • Idle - Red

It seems like something is tripping the E-stop input the moment the drives energize, but I’m not sure what to check next.

If anyone has experience with the M700 + UC400ETH combination or knows common causes for immediate E-stop triggers on jog commands, I’d really appreciate some guidance.

Thanks in advance!