Quote Originally Posted by JAZZCNC View Post
It's case of not being repeatable. [...] The random delay between when switch is triggered and time takes relay to open it's contacts to allow message to control makes repeatabilty impossible.
Get it :) Sounds obvious now :)


Quote Originally Posted by cropwell View Post
I use the LJ12A3-4-Z/BX proximity sensors. Brown wire is to supply +ve, Blue to GND and the Black wire switches to GND
I looked up on AliExpress but not sure I get original ones... where do you get them from ? Also, If I understand well the wiring you explain and look at the documentation as well, it seems that you're connecting them as PNP type sensor and that blue connects to both 24V PSU GND pin and BOB's input terminal's GND pin ? Is it not an issue that they share they share the same GND though they are circuits operating at different voltages ? I guess GND is GND, doesn't matter the voltage ? I like to fully understand things, that's why I ask ;)


Quote Originally Posted by paulus.v View Post
You will also want to wire the alarm outputs from your drive through a relay to the same limits + e-stop relay loop. In this case if one drive gives an error, the other will stop as well.
That's a very important thing you note here, and I will modify my circuit to take drives alarms into account, in fact, last week I made a mistake in Mach3 and while running un-regenerated toolpath and bad configuration, motors stalled, so I almost broke my X axis, because the alarm went off, but obviously was not connected to anything, so X2 kept running... To avoid that in the future I'll wire the alarm outputs as you explained, thought the limits don't belogn to the e-stop circuit. Thanks for the advice :)