[prelibation]

Greetings.
My first post, but not new to this forum or to CNC. In the past I've converted a lathe to CNC and built a small CNC milling machine. Both running Mach3 with parallel port cards. For a recent project (laser cutter) I got an inexpensive USB card from China. It appears as BSMCE04U or STB4100, probably other designation, but all seem the same (photo and suggested wiring diagram attached).
The cards works well (under windows 7) except the shearing of limit and home switches. In past project I have used the same switches as home and limits, but when I try to do it in this card it trips a limit imminently when first axis reaches home.
I think this was discussed here before, but I am wondering if anybody found a solution or a scrip that will disable the limits while homing. I've tried to do a Brain script, but I am not too good at this.
Thanks!
Bill

[DoubleHelix]

Looks similar to this, maybe some of there literature will be helpful ???

https://buildyourcnc.com/item/electr...ach3-USB-Board

[A_Camera]

I can't help you with that specific card but beware, don't use normally open switches and don't connect them in parallel.

[prelibation]

Thank you for the link. It is indeed an identical card (except different connectors) and - unfortunately - the same instructions and diagrams.

[prelibation]

This is exactly what I did in the past with parallel port BOB. I am using one switch for each axis; the switch works as home in the homing cycle and then as both end-of-travel limit actuated by an eccentric limit. Unfortunately in the USB board there is not enough inputs for each switch (hence the parallel connection) and, as indicated originally, the switch is not ignored (still acts as limit and stops the operation) during homing.