Program Too Large

[Tigamaroo1999 0]

PLC - CJ1M-CPU22 Touchscreen - NS5 My program is too big. What can I do? Thanks! Tig

[BobLfoot 302]

I assume from your post that using a Cj1M-CPU23 with double the allowable steps is not your preferred option. I'd suggest you revisit your programming and look for any means of consilidation. Using Word statements rather than several bit statement.

[Tigamaroo1999 0]

I have a slot for a CF Card. Does that buy me any extra real estate? This program is huge. I'm only 80% done, and already 1220 lines over the limit... I could consolidate some, but I'm not sure that I'll be able to shrink it down that much...

[gtsuport 61]

Sounds to me like BobLFoot has the right idea. Talk to your disty about a CPU23. I really don't think the CF card will help with ladder space. If I remember correctly, you can load programs from the card. Per W394-E1-3 Section 5-3-2 (not sure if this is the latest version) you can replace the program during operation. Procedure is detailed in the manual. Frankly, this would scare the heck out of me, but it may depend on your app. Based on your cpu, you must be doing high speed counting or pulse output. I did not see any estimate of time requred for transfer. Hope this will help.

[Andy_P 7]

I would have to agree with the other posts and say that the CPU23 route would be the preferable option. Even if you managed to squeeze your program down to fit into the CPU22, there will ALWAYS come a time (in my experience) when something needs to be added / modified and hence push you over the limit again. Having a CPU that tight for space is not a good idea, in my opinion. Andy.

[Tigamaroo1999 0]

That's kind of what I thought, but I thought I'd query the experts! Thanks for your help! Tig

[BobLfoot 302]

I've had a nights sleep since my last post and had one other thought. I had a job one time where an AB PLC 5/80E with Maximum memory was too small for the program we were tasked to write. We had a memory architecture in mind we wanted to stick with and the machine was big enough we added a PLC 5/40 and messaged the required handshakes signals back and forth between the parts of the system. You might add a second CPU22 and let it handle half the machine and your current one handle the other half. If your disty won't make you a deal on swapping a 22 for 23 then a second 22 is cheaper than a 23. You'll spend more on design and programming, but might have a better machine in the long run. Just food for thought.

[Tigamaroo1999 0]

Ok, got out the books. The specs on the CPU23 are almost identical to the CPU22 with the exception of the availability of 640 I/O (versus 320 I/O for the CPU22). My program itself is too large. Both PLC's limit me to 10k words for program memory and 32k words for Data memory. The error I am getting says the following: ERROR: Total output image exceeds UM size by 1356 words. The advice I received doesn't address this error, right? At this point, can I put part of my program on a memory card (like the section that sets all my variables for a particular job)? Thank you!

[MiniH 0]

Tigamaroo1999, CJ1M-CPU23 has 20K program capacity not 10K.

[Andy_P 7]

Agreed.

[Tigamaroo1999 0]

It's Ironic. If you look at the Programmable Logic Catalog, page B-8 says that a CPU23 program memory size limit is 10k, but if you turn to B-12, it says it's 20k. I am glad you pointed that out to me! Thank you all, once again, for your patience and help! Tig

[scottmurphy 1]

By the nature of you posts, I am assuming that you do not know about the "Memory View" function. If you click 'View', 'Memory View', it will tell you the current size of your program. If you keep an eye on this as you are developing your code, you will get earlier warning rather than when you come to download your code to the PLC. If you are over the limit for the CPU, the remaining memory left will be a -ve.

[james_applied 0]

Rememeber that function blocks are very memory hungry.

[Jay Anthony 118]

I was suspecting that, too.

[Nathan 7]

[rant] This is out of control! Surely vendors realize that it's not the 1960's anymore. How much would it really cost them to expand 10k of memory an order of magnitude or two?[/rant] Edited 19 Apr 2008 by Nathan

[james_applied 0]

Not a lot, but at the end of the day they are there to make money. And big programs are more complex which means more support may need giving.

[Guest anonymous]

Nathan, It's percieved value... If I only need 10K memory space, why should I be seen to pay for something that has 20K memory space? Obviously, that extra 10K ain't free. (or is it... ).

[scottmurphy 1]

Nathan, It's percieved value... If I only need 10K memory space, why should I be seen to pay for something that has 20K memory space? Obviously, that extra 10K ain't free. (or is it... ).