Rslog5000 online edit problem

[suboliu]

Hello everyone,
Today when I online edit Rslogix5000 program, it always said" Error: unable to allocate sufficient stack space to execute all ADD_ON instruction contained in program"
so what should I do?
any suggestion appreciate!

 

[dmroeder]

KB 601193 suggests that your processor memory usage is full or near full. Check the Memory tab on controller properties to verify if this is true.

 

[suboliu]

KB 601193 suggests that your processor memory usage is full or near full. Check the Memory tab on controller properties to verify if this is true.

yes, it is true!

 

[dmroeder]

Bummer! I guess you'll have to find ways to free up memory or upgrade. Just out of curiosity, what processor is it?

 

[suboliu]

Bummer! I guess you'll have to find ways to free up memory or upgrade. Just out of curiosity, what processor is it?

1756-L71SControllLogix5571S safety controller

 

[ASF]

That's the smallest of the range, so the good news is, it would be an easy fix to swap it out for a 1756-L72S or higher.

Easy, and of course, hideously expensive. Your budget gets nervous every time you utter the magic "s" word (safety).

As dmroeder suggested, you might be able to free up some memory programatically to get you moving again, but it depends - if you're only going to keep adding to this PLC, you're going to have to upgrade it at some point. So you might as well bite the bullet and do it now, rather than spend too much time and effort only to have to replace it in 6 months anyway

 

[LaloO]

@dmroeder, Thanks for the info!

 

[Aardwizz]

You can clear up easy space by going to the tags and filtering by Unused and deleting anything there. Do it online so that if an HMI is using one, you won't be able to delete it. Do it for both controller-scoped and every program-scoped tag file.

I once had a SLC that was out of memory, and it was the largest model. Looking through the code, I found very inefficient uses of memory: data being moved from lots of different places instead of a single COP. I got to the point that I was even replacing MOV 0 <tag> with CLR <tag> instructions, because the former takes 3 words of memory (1 for the instruction, 1 for each element), while the latter takes only 2.

It was a PITA, but in the end, I wound up down to only 90% full, and a much more organized system.