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Author Topic: Limit switch issues  (Read 19203 times)

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Offline stirling

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Re: Limit switch issues
« Reply #130 on: December 28, 2015, 08:53:11 AM »
yeah, they are wired N/C so 5 vdc is constantly going through them so the x'd out column in the active low settings column makes sense now...

Glad it makes sense to you because unless you have signal inverters in there somewhere which you haven't mentioned, then it makes NO sense at all.
Re: Limit switch issues
« Reply #131 on: December 28, 2015, 09:03:05 AM »
why are you being such a troll? you get off on it or something?

If I understand the terminology correctly, if they were wired normally open, then the setting would need to be active low...since there is always current going through them and they are wired normally closed, active high is the correct setting...

No inverters necessary....

Offline bfgstew

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Re: Limit switch issues
« Reply #132 on: December 28, 2015, 09:17:03 AM »
LOL - you're both right of course - but given the way this thread's gone so far, aren't you both making the rather rash assumption that Mike's view of Ohm's Law is the same as everyone else's?  >:D

And what has Ohms law got to do with it, or any law come to that. The guy is/was having difficulties, yes the thread went on and on, but it got resolved. The fact that a global moderator has to ridicule or belittle someone baffles me???? Or is it ok for you to do that????
« Last Edit: December 28, 2015, 09:31:20 AM by bfgstew »
Re: Limit switch issues
« Reply #133 on: December 28, 2015, 09:34:06 AM »

If I understand the terminology correctly, if they were wired normally open, then the setting would need to be active low...since there is always current going through them and they are wired normally closed, active high is the correct setting...
 

This is where you are misunderstanding the description of Active HI / LOW.

All switches NC in series to one pin is holding the pin HI while in the normal running condition.
If that input pin ever goes LOW, tripped switch or broken wire ...., that will activate the EStop.  Hence, Active LOW.

If all switches were connected NO in parallel to one pin, the pin would be LOW while running normally. Making the pin HI would activate the EStop. Hence, Active HI.

NC and Active LOW is best as it accounts for any break in the circuit making it a bit safer.

Hope this helps,
Russ
Re: Limit switch issues
« Reply #134 on: December 28, 2015, 09:40:16 AM »
yeah, that's what I gathered from reading (and partially lol) understanding the manual....

But mine are wired in parallel and N/C.....hence why active low is not checked in the setting box....(I guess lol not 100% on this)...but it works, that's the main thing! :-)

When I re-build, I'll wire up all the switches in series as Stew drew in the wiring diagram....and change the settings....

Offline Davek0974

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Re: Limit switch issues
« Reply #135 on: December 28, 2015, 10:23:56 AM »
All parallel AND N/C can't work, sorry.

The only time that circuit could function is when ALL the switches were opened at one time.
Bridgeport Mill, Mach3 V062, CSMIO-IP/A controller, AC Servo Drives
Re: Limit switch issues
« Reply #136 on: December 28, 2015, 10:32:23 AM »
Hi Dave,
I think these are to individual pins. Parallel is a moot point.

Offline Davek0974

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Re: Limit switch issues
« Reply #137 on: December 28, 2015, 10:36:11 AM »
Hi Dave,
I think these are to individual pins. Parallel is a moot point.


D'oh! I was only going on what was written ;)
Bridgeport Mill, Mach3 V062, CSMIO-IP/A controller, AC Servo Drives
Re: Limit switch issues
« Reply #138 on: December 28, 2015, 10:36:22 AM »
Hi Dave,
I think these are to individual pins. Parallel is a moot point.


exactly....

Online Tweakie.CNC

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Re: Limit switch issues
« Reply #139 on: December 28, 2015, 10:50:37 AM »
Hi Mike,

So what exactly is it that you have done to cure the problem ??

Tweakie.
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.