Jump to content

Recommended Posts

I have making app for plc v570 but for some reason direct store  dont get value as you can see everything is good  but i don't understand why don't assign the value if i make some error can you explaing me pls. in the image you can see on net 96 the value is assigned but in 97 must change the value an cont change nothing.

 

storefails.png

Share this post


Link to post
Share on other sites

Hi Kikep

Try putting the reset coil of MB49 after the store direct.

You may be resetting the contact before it gets the chance to store the new value.

Regards

Denis

 

 

Share this post


Link to post
Share on other sites

Try seeing what is actually happening by doing an STL View of the network - right click on the network number itself and select "STL View" from the drop-down menu.

Often Visilogic will re-compile a large network and create local internal bits to run the logic.  You'll know it's doing this if you see LB 0 in the resulting statement list.  This is a downside of what Visilogic allows you to do by stacking outputs in series - it doesn't always work the way it looks like it should.  

The previous posts are probably correct - the PLC is probably solving mini-rungs and your reset of MB 49 has killed your STO block.

Joe T. 

  • Upvote 1

Share this post


Link to post
Share on other sites

Just move the MB 49 Reset to the next rung gated by the MI 1 comparison. There is no reason to try to cram too much logic into a single rung. Unitronics will not charge you by the rung. :)

It's always better to break up outputs to have a single one for each rung to avoid large network compile problems.

  • Upvote 1

Share this post


Link to post
Share on other sites
On 01/11/2016 at 0:13 AM, Flex727 said:

It's always better to break up outputs to have a single one for each rung

And here I was thinking I was old-fashioned in sticking to this routine.  Glad to see someone else always does this!

And thanks Joe for the STL View explain about recompiling.

cheers,

Aus

Share this post


Link to post
Share on other sites
19 hours ago, Ausman said:

And here I was thinking I was old-fashioned in sticking to this routine.  Glad to see someone else always does this!

And thanks Joe for the STL View explain about recompiling.

cheers,

Aus

I usually try to stick to one rung, one output.  Sometimes I get lazy, sometimes I don't.  The only way to guarantee your program works as intended is to do it every time.

We had a very weird issue once with a PLC controller test station that popped up after a software update with another manufacturer.  Turns out their compile routines changed slightly on how they processed the logic, which changed the order of the final program execution.  I've also seen the same issues when duplicating programs across two different manufacturers.

 

You are not alone.

 

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...