Machsupport Forum

Mach Discussion => Mach4 General Discussion => Topic started by: patrickdam on September 05, 2025, 11:39:42 PM

Title: Mach4 – Z Axis Limit Switch Not Triggering During Homing Cycle
Post by: patrickdam on September 05, 2025, 11:39:42 PM
Hi everyone,

I’m currently facing an issue with my Z-axis homing routine in Mach4 and was hoping someone here might have some insight.

The setup:

Controller: Pokeys57CNC

Mach4 (latest build)

Limit/Home switches wired normally-closed

Diagnostics window shows inputs changing correctly when switches are pressed

Here’s the problem:
When I run a homing sequence, the Z-axis starts to move upward but never stops at the Z home switch. The diagnostic panel shows the switch toggling, but Mach4 doesn’t seem to register it as a “home” event. Instead, the axis just keeps moving until it faults out as if no switch was ever triggered.

What I’ve tried so far:

Swapping the Z switch with the X-axis switch → the physical switch works fine as an X home.

Checking input assignments in the Mach4 control configuration → they appear correct.

Verified with the Pokeys plugin diagnostics → Z switch activation is detected.

Tried reversing homing direction → no change.

So, the hardware and wiring seem fine, but Mach4 isn’t treating the Z home input as a valid homing signal.

Has anyone run into something similar with Mach4 not linking the home input to the actual homing routine? Could it be a signal mapping issue inside the plugin or something I’m missing in the homing/limits configuration?

Any advice, suggestions, or troubleshooting steps would be greatly appreciated!

Thanks in advance.
Title: Re: Mach4 – Z Axis Limit Switch Not Triggering During Homing Cycle
Post by: Cbyrdtopper on September 08, 2025, 08:58:40 AM
I do not use Pokeys, I use the HiCon.  I have had this issue happen once before; my homing inputs were plugged into my plc and communicating with Mach4 over modbus. 
For the HiCon, the homing and probing inputs MUST be plugged into the hicon itself. 
I don't know how you have yours inputs physically mapped, but for me that was my issue.