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View Full Version : Home limit switch wiring.



DAB_Design
12-17-2004, 06:21 PM
I picked up some switches today, and was reading through the Mach2 manual to figure out how to wire these.

Anyone care to check it over? My only questions (unless it is done wrong) is in the manual, it says to try and ground at the main control ground. Would it be ok to run the grounds to the capacitor, or should they go to the PC case that the controller is setup in?

Note: The image is not pretty, guess I'm showing my electronics ignorance again. :)

DAB_Design
12-17-2004, 06:24 PM
Oops, image was too big.

Bubba
12-17-2004, 06:39 PM
Dab,
I am NOT real familuar with Mach2, but I don't think it will work as drawn! You need the NO limits to be NC also! As it stands, the circut is always open due to the limits and would never know if the NC switches opened.

Wire the NO switches as NC, and I think it will work if properly set up in Mach2
Bubba

DAB_Design
12-22-2004, 01:21 PM
I played around with it toady. Had everything wired up and just laying on the bench. Wired 2 switches NC as you stated. When Mach2 was started, it imediately gave a "limit switch triggered". It wouldn't clear. So I pressed and held one of the switches, and was able to clear it. As soon as I let go though, I got the same alert.

So I thought that maybe I was right the first time (one switch NC the other NO). This had no affect. When I tried to home the axis, pressing and releasing the switch did nothing.

So um....any ideas on what may be wrong? I read something in the manual about active hi and active lo, but did not see any settings in the config screen that I could change for this (on the input pins tab).

The manual says "...they need to be connected so the signal is a logic "1" if either switch is operated (i.e. the logical OR function)"...."If they have normally closed contacts and are wired in series as shown, then they will give an Active Hi signal"

Bubba
12-22-2004, 04:38 PM
Dab,
I am not real familiar with Mach2, but check your "Input Signals Page" under configuration and see if that will handle your active hi or low.
There are many around here that are very knowledgeable about mach2 and I am not, but willing to try and help.
Its there, we will just have to find it and make it work!

Bubba

PS: you will have to have the switches wired the same configuration as suggested earlier if you use that type of scheme.

Torsten
12-23-2004, 06:48 AM
I played around with it toady. Had everything wired up and just laying on the bench. Wired 2 switches NC as you stated. When Mach2 was started, it imediately gave a "limit switch triggered". It wouldn't clear. So I pressed and held one of the switches, and was able to clear it. As soon as I let go though, I got the same alert.

So I thought that maybe I was right the first time (one switch NC the other NO). This had no affect. When I tried to home the axis, pressing and releasing the switch did nothing.

So um....any ideas on what may be wrong? I read something in the manual about active hi and active lo, but did not see any settings in the config screen that I could change for this (on the input pins tab).

The manual says "...they need to be connected so the signal is a logic "1" if either switch is operated (i.e. the logical OR function)"...."If they have normally closed contacts and are wired in series as shown, then they will give an Active Hi signal"

I dont think you need to feed the external 5volts in.
But both switches need to ether NC or NO not mixed.
Just wire them between ground Pin and the trigger Pin.
If you wire them NC you need to wire them in series.
If you wire them NO you need to wire them in parallel.

Try one of the 2 methodes if it dose not work use the other.

This is because some trigger Pins are inverted so depending
on the Pin used one or the other methode should work.

Good Luck