View Full Version : Need Help! Random E-Stop signals

11-17-2017, 06:15 PM
Hi, A few years ago I bought this set:

CNC Bauteile -- 5 Achsen Interface + 4 X Einzel-Schrittmotor-Steuerung M542H | eBay (http://www.ebay.de/itm/CNC-Bauteile-5-Achsen-Interface-4-X-Einzel-Schrittmotor-Steuerung-M542H/352155524499?hash=item51fe1add93:g:ZywAAOSwj9lZp~Fo)

I'm just now getting to set up a portal mill and am having odd problems with it. If I hook up limit switches I can't get Mach3 to reset to allow the steppers to move. Mach3 says "external E-Stop activated". I have checked the wiring about 50 times and replaced all cables with one shielded cable per limit switch. This goes for the e-stop as well. If I disconnect the limit switches it will work for a few seconds to a minute and then stop again. In the diagnostics screen, there is no indication that the e-stop was activated. Running G-code has no effect. Configuring Mach3 to run without e-stop and disconnecting the cable seems to extend the amount of time before it shows up again.

Normally I would guess RF-noise but I have everthing in a grounded metal housing and all cables are shielded so I don't see how that's possible.

If anyone has experience with this set or can make a suggestion what to check next I would very much appreciate it.


11-18-2017, 11:03 AM
A few prior posts on the subject.

11-18-2017, 03:34 PM
Thanks but that isn't the problem.
I've tried all of the solutions I can find in other posts here but nothing seems to solve it. Getting desperate, I checked some of the signals with an o-scope but everything seemed fine. Until I checked the DC from my 48V PS. There seems to be a tremendous amount of noise coming from it. 22Vpp at about 22 kHz. I'm going to order a new power supply and see if that solves to problem.

11-24-2017, 02:56 AM
I received my new PS and the problem is solved. If the solutions mentioned in other posts (debounce setting) don't work and you followed the grounding principals Al has suggested but still have erratic behavior then check your voltages with a scope to make sure they are clean.