Mach 3 ports and pins problems,

[Neale]

Does the false limit trip happen with one axis in home position, or away from home position? I had a similar problem which was caused by the Z axis homing but not moving far enough from the prox switch once homed and causing it to randomly trigger while the other axes were moving. This was also with CSMIO. Fix (thanks to Jazz) was to set Z home position offset 0.5mm from physical home position (Mach3 homing parameters) so trigger clear of switch. Have not had a false trigger since. I had worried that it might be noise problems (limit switch and motor cables in same cable chains, etc) but CSMIO seems pretty good.

[Tom J]

Does the false limit trip happen with one axis in home position, or away from home position? I had a similar problem which was caused by the Z axis homing but not moving far enough from the prox switch once homed and causing it to randomly trigger while the other axes were moving. This was also with CSMIO. Fix (thanks to Jazz) was to set Z home position offset 0.5mm from physical home position (Mach3 homing parameters) so trigger clear of switch. Have not had a false trigger since. I had worried that it might be noise problems (limit switch and motor cables in same cable chains, etc) but CSMIO seems pretty good.

Neale
Its quite hard to determine what actually happens, as there is no light either on switch or input light on module when trip occures.
My sensor is close to the motor Z - even closer after upgrading them for bigger 8 cables one.
[ATTACH=CONFIG]21360[/ATTACH
Dean's feedback open my mind to one thing. I use HV enable with manual start push button, so after reset nothing happens till I press the button and send current the motors.

- (drawing not complete yet)

There must be poor screen on signals cable from switch - will moved input to different axis to see if this will send the same fault - think it will.
I run all cables in one chain - no so much room left 30% maybe, it is last time when I us such a small control box - much harder to work with - small machine small box:)