Author Topic: Limit switches ignored after re-install  (Read 2283 times)

0 Members and 1 Guest are viewing this topic.

Offline Overloaded

  • Global Moderator
  • *
  • Posts: 4,783
    • View Profile
Re: Limit switches ignored after re-install
« Reply #10 on: October 31, 2015, 08:35:39 PM »
You definitely have something else going on.
The standard RAH button de-references the axis first, then runs the internal homing routine, is does not return them to any predetermined position, it re-references the axis's in relation to the switch trip. If Auto Zero isn't checked, the only way it would show 0.000 when done is if there was a persistent position set earlier. Only a very precise machine would repeat to exactly zero .. which may be the case though.
I'd just run Mach3 without any extra scripts or plugins to verify that Mach3 works (or not), then go from there.
Russ

Offline JT1991

  • Active Member
  • Posts: 7
    • View Profile
Re: Limit switches ignored after re-install
« Reply #11 on: October 31, 2015, 11:07:47 PM »
Overloaded,

Thanks (again) for your help.

What you describe is exactly how the machine worked before the re-install.

As part of the last re-install, I did as you suggested - a bare install  sufficient to get the axes drives working and then one config setting at a time, leaving the X-Box and zero script to last.  For limit switches, I worked on the Z axis (because that's where Ref All Home goes first) testing all possible settings - to no avail.  I removed the Z axis from the RAH script, but same result with X and in turn, Y. 

It seems either DoButton(24,23,22 and 25) have somehow gone blind to their limit switches, or one of my settings is somehow blinding them. Can't find what though

This in spite of the settings being exactly as they were before I re-installed the crashing Mach3 (when loading some, but not all text files) I took particular care as it took me a while and some study of the manual and this site to get those settings correct.



That is, the machine would move to Z switch, and on trip back off slightly and then zero the Z axis machine coordinates. It would then repeat for the X axis, and instead of Zero would set X Machine coordinates to 395 (The value set in Homing/Limits). It would then to the Y axis as for Z.

What happens now is it starts the same routine.  But it never gets past Z.  Z moves up as it should, but then blows straight past the limit switch to a hard stop. This in spite of the limit switch showing activated in Diagnostics.  In other words, Ref Home (Standard Script) does not seem to be getting a limit switch signal, or is ignoring it.


Further experimenting shows the limit switches are acting as an emergency stop if triggered (by hand) during movement. Also, the tool sero script is working, after I reduced the lift up from the touch plate so Z did not go near its limit switch.


In every other respect MACH3 is working as it should.  Dry running simple files works fine.  The X-Box works fine.  My substitute script to do a G28 on button "Display Mode" works fine. 

Everything works as it did and as it should - except "Ref All Home" ignores tripped limit switches. 


My poor head is spinning from all this, so I will take a short break before I connect the other PC (complete with its working MACH3 installation), configure that and see what happens.

Thanks again for your help.

Have any of you that looked at the xml file found anything incorrect or unusual?

Offline JT1991

  • Active Member
  • Posts: 7
    • View Profile
Re: Limit switches ignored after re-install
« Reply #12 on: November 01, 2015, 11:35:47 PM »
Thanks everyone for your help, but I am pleased to say I have found and fixed the problem.  I have donned my dunce hat to write this.

I attached the spare PC, re-configured and got the same problem. 

I REM's out the first line of the RAH button script and found the Y axis (next in the sequence) worked as advertised. 

One coffee later the shoe dropped.  I had the pin assignments for Z and X reversed.  The sequence of these in the Ports & Pins screen meant that the middle one (Y) was correctly assigned and worked.  My carefully constructed spreadsheet had a dyslectic error, now corrected.

Thanks again everyone.