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Author Topic: >>> Clearing a spurious limit_hit_latch event event.. Issue at start up  (Read 698 times)

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Offline jevs

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This is in my history at start up of Mach 4 every time. I am running the latest Mach 4 and ESS plugin (just updated the ESS today 2/10/20 and it still happens). My Mach version is still at the recommended version.

E-Stop condition!
E-Stop cleared!
>>> Clearing a spurious limit_hit_latch event event. Start Logging in 'Menu-> Diagnostic-> Logging...' to see more details.

Everything works fine after this so far, but I am not sure why I am getting that "Clearing a spurious limit_hit_latch event event." at start up

It homes fine to the home switches every time and works fine after this. The actual limits work fine also (kicking everything off).

Of course turning on the logging does me no good, because it only happens at opening of Mach4 and the logging can only seemingly be started after Mach4 is opened.

I cannot remember if this was happening before. I was working on my machine for awhile (rebuilt ball screws and new support bearings). I did change the ways oiler to come on whenever Mach4 is enabled rather than when an axis is moving.
Re: >>> Clearing a spurious limit_hit_latch event event.. Issue at start up
« Reply #1 on: February 10, 2020, 10:21:34 PM »
Hi,
one possibility is that you have one or more limits as 'active high' say, but they do not actually go high until Mach has fired up or at least well
through the start up  process.

It might be appropriate to deliberately disable limits and the end of a session (Screen Unload Script) so that at the next start up there are
no limits, and then in the first run of the PLC script which runs ONLY once Mach is fully up and running have the PLC script enable the limits
again.

Craig
My wife left with my best friend...
     and I miss him!

Offline jevs

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Re: >>> Clearing a spurious limit_hit_latch event event.. Issue at start up
« Reply #2 on: February 11, 2020, 12:44:03 PM »
From memory looking last night I think the limit switches are active high and the homes are active low. I will look into your suggestion and see what I can find.
What is odd is that I do not recall getting this last time I was messing with programming, but now that I got side tracked a couple months I have to refresh on all of this.
Thanks!

Offline jevs

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Re: >>> Clearing a spurious limit_hit_latch event event.. Issue at start up
« Reply #3 on: February 11, 2020, 11:16:32 PM »
I figured out this is happening because the way my limit switches are wired in series with the E-stop circuit. This way it kills everything if a limit is hit (could be bad if the computer loses it's mind).
I also have a an input tied to this for the limits. This is being held at 24V until Mach fires up, then it goes low like expected.

This is also likely what is causing my E-stop messages at boot.

Not really sure what I can do to fix these from not happening. The E-stop circuitry is on the Machmotion IO6 BoB (originally designed for Mach3 I guess).

It's working fine, but these false messages at boot are annoying and if I don't use the machine for awhile and forget, I will be wondering why it is happening again, or if someone else ever used it, they would think there is a problem.
« Last Edit: February 11, 2020, 11:18:36 PM by jevs »

Offline jevs

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Re: >>> Clearing a spurious limit_hit_latch event event.. Issue at start up
« Reply #4 on: February 11, 2020, 11:45:50 PM »
I was doing some more searching. It looks like this problem has always been there and I kinda dealt with it before.

Apparently Warp9 changed something so the messages I am seeing at bootup are different and in a different order. Now the worst one is showing up last and hanging out in the message bar. grr

https://www.machsupport.com/forum/index.php?topic=41685.0

It would be nice if I could get rid of all these, but this explains why I didn't remember seeing this before. They changed the wording and the order of checking and reporting I think!

If I knew how to turn off and on the limit reporting as you suggested, that would maybe get rid of the worst message, but I am not sure what the programming is to do that....

My limits will do their job regardless of this message at bootup or anything the computer or ESS is doing. I would like to keep it that way.



Offline jevs

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Re: >>> Clearing a spurious limit_hit_latch event event.. Issue at start up
« Reply #5 on: February 12, 2020, 11:06:05 PM »
I was finally able to solve the spurious limits message. The only way I could do it was to add another relay to isolate the E-Stop to my Machmotion I06 BOB from anything to do with the limit switches. I ended up using another relay on the BOB to break the signal to the enable relay if the limit circuit is opened instead.

There is no way I can get rid of the E-stop messages that I have found so far. That occurs due to using the Machmotion IO6 BOB E-Stop terminals along with the Pokeys for reporting the E-stop through the ESS. That little cycle of changes at bootup does not seem to be avoidable in reporting it. At least the displayed message after boot is that the E-stop is cleared instead of that spurious limit stuff.

I believe the way the Machmotion board works is that the E-stop circuit is not working until Mach is booted, so you get that 24V on the circuit before Mach Boots and the E-Stop circuit gets going. Then it pulls low. If I had a schematic of the board I might know more or see a way to do it...

If anyone knows of a way to get rid of that, let me know...

Would be nice if Pokeys, Mach, or Warp9 had a solve for that. It would be nice to just get a clean boot with no message at all (when the E-stop is not activated already).

Offline jevs

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Re: >>> Clearing a spurious limit_hit_latch event event.. Issue at start up
« Reply #6 on: February 13, 2020, 08:03:32 PM »
Okay! I got rid of all the bootup messages now. Mach4 boots clean finally with no messages (unless something is really an issue).

I took the second set of E-stop contacts off the Pokeys input and did a 5V loop to the 2-15 input on my Machmotion IO6 BOB. 2-15 is now telling Mach the E-stop is on or off (even though the actual E-stop critical functioning works off the other contact set. Function and reporting are now correct, even at boot.

Works perfect! (Limits and E-stop).