Author Topic: x++limit switch triggered accidentally while referencing towards x--home  (Read 2015 times)

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Offline kibrahacha

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My table has 4 limit switches . 1 for x++, 1 for x-- which is also x home, 1 for y++, 1 for y-- which is also y home.They are wired in series , normally closed , port 1 pin 11.
I was referencing the x-axis, gantry going towards the x-- switch when I accidentally touched the x++ limit switch(was vacuuming the table) . could not get mach 3 up running with limit switches as I had to go into port and pins and deactivate the switches. Changing the active low/high setting didnt make a difference.
 The switches were working great before when referencing as the gantry would touch the switch and then automatically back off just enough so the switch would close again.
I suspect a bad limit switch and will check them by checking my wires for any breakages and the switches themselves for continuity. meantime I'm cutting without limit switches.
Anybody have similar experience?Help.

Offline Hood

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How have you got the limits and homes wired. It sounds like you are sharing inputs, if that is the case then it should have just acted like your axis had reached the home. Limits are disabled whilst homing.

Hood

Offline kibrahacha

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Yes. am sharing 6 inputs on one pin#11. In my diagnostics screen. under port 1 pins current state . top row 7th column green light is stable on, nx to it top row 8th light flashes green same time as my limit switches flash yellow. after I have changed the active low setting in my config screen , ports and pins , input signals. I revert with my findings after I check my switches for continuity in NC position.other than that I still have not come up with any other soultion as to what the problem can be.
Andy

Offline kibrahacha

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found the problem.It was a severed wire connection on the limit switch that I accidentally hit .The wire parted behind the soldered connection and I couldn't see it due to the heatshrink covering.When I did the continuity test on the wires coming from the switch, no buzzing.But when I did the continuity test on the actual limit switch posts I did get a buzzing for continuity. When shaving the heatshrink back with a blade I could see that the wire had parted right where the solder ended.Did same continuity test on the limit switch posts for the remainder 3 switches and all were good. So happy to have figured it out!
HOOD , Thanks for your reply , it helped to narrow things down to the solution.
Andy

Offline Hood

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Glad you got there and it shows the importance of having normally closed limit switches :) If they had been Normally Open switches the first you would have known was when the axis didnt stop at the limit switch.
Hood

Offline kibrahacha

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Yes. Thats the reason why I wired the limit switches normally closed and I'm so glad that I did.Just makes good sense.
Thanks again.
Andy