Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: Chet on June 10, 2011, 05:10:29 PM

Title: False Limit Switch Emergency Stops & audible alarm
Post by: Chet on June 10, 2011, 05:10:29 PM
For some reason I've started getting false Limit Switch Emergency Stops.
They don't occur at any particular frequency, nor any particular place.
This is a new problem in an operation that's worked well over the past two years.
AND secondly, is there a pinout from Mach3 so an audible alarm could be triggered if there is an Emergency Stop?
That would sure be handy!
I typically let Mach3 run without constant monitoring, and an audible alarm would let me know something was triggered...
Chet
Title: Re: False Limit Switch Emergency Stops & audible alarm
Post by: Hood on June 10, 2011, 05:15:52 PM
Sounds like you either have noise or possibly a worn switch that is triggering with vibration.
Hood
Title: Re: False Limit Switch Emergency Stops & audible alarm
Post by: Chet on June 10, 2011, 05:21:19 PM
Thanks, Hood, you always good ideas.
But the solution may be difficult to implement...
I've got my limit switches wired in series.
Finding the faulty intermittent one will certainly be problematic.
AND is there a pinout for an audible alarm?
Chet
Title: Re: False Limit Switch Emergency Stops & audible alarm
Post by: Hood on June 10, 2011, 05:29:59 PM
Audible alarm may not be so easy as Mach turns off all outputs when in E-Stop. One way you could do it is via a NC relay and power the relay when Mach is not in E-Stop, maybe the Enable. When Mach goes into E-Stop then the relay would close and you could have a buzzer or light or both connected to the relays contacts.

Regards the limits, it may be possible to jumper across the terminals on a limit one at a time to see if you can narrow down the fault.
Hood
Title: Re: False Limit Switch Emergency Stops & audible alarm
Post by: BR549 on June 10, 2011, 09:18:35 PM
You could wire the alarm relay with an inverse function.  When the relay (normally closed) turns OFF the allarm comes on.

Justa thought, (;-) TP