-70119 limit switch error

[serkanb]

Hello,

My system includes 4 PCI-7358 cards, some brushless and brushed dc servo motors.

Mostly it works fine for a while but sometimes (randomly) some of the axes starts to throw modal error (-70119 limit switch error)

Limit switches are disabled from MAX and I also disabled them from software.

What could be the problem here? Could you help me please?

Kind regards...

[MissFitt]

Hello serkanb, 

I was able to find you a Knowledge Base Article that discusses error -70119. Usually the issue is from the wiring of the switch or trying to move further than the active limit switch. Since you have disabled the limit switches, I would check your wiring. Also, there was a known issue with this in NI-Motion 6.0 that was fixed in later versions. What version of NI-Motion are you using? Hope this helps!

Mychal F

[serkanb]

Hello,

Actually there is no limit switches. There are two stoppers at both sides. My sytem runs a search alogrithm to find limits during initialization.

Here is my pseudo algorithm:

   // finding forward limit

   Go forward with slow speed.

   Repeat

   {

      FollowingError  = ReadFollowingError()

   } Until   ( FollowingError  > Following_Error_Threshold. )

   Halt Stop

   Wait 100ms

   ForwardLimit = ReadEncoderPosition()

   Go reverse -1000 count  // to get rid of stiffness of string.

   // find reverse limit

   Go reverse with slow speed.

   Repeat

   {

      FollowingError  = ReadFollowingError()

   } Until   ( FollowingError  > Following_Error_Threshold )

      Sometimes, not every run, system throws a modal error -70119 here!

   Go reverse 1000 count  // to get rid of stiffness of string.

   Halt Stop

   Wait 100ms 

   ReverseLimit = ReadEncoderPosition()

   FindIndex();

  What could be the problem here? Could you help me please?

  Kind regards...

[MissFitt]

Hello serkanb,

Thanks for sending me the screen shot of your code! Could you also send me a screen shot of your limit switch settings in MAX (like the setting shown in the Knowledge Base article I linked you previously)?

Are you using an UMI? Also, what is currently wired to the limit switch pins on your controller?

I believe it may be a wiring issue since your code looks alright to me. Hope this helps and have a great day!

Mychal F