Checksum = 0?

Hey guys,

Odd little problem I thought maybe you all could help.

One of my guys has been offline editing our RS500 program with some changes for an upcoming line change and we tried to upload it today and found that it wouldn't go. Said it was out of image memory.

After looking around a bit, I came across the controller properties and found that the program checksum was 0 and there was only an asterisk present in the memory used and memory left spaces. I assume that since there isn't a value in those memory slots, the program won't download and that's why I'm getting my memory error as the program is small enough that it should fit on the controller.

Any thoughts on how I can either edit this program so that it will go or how I can extract all the rungs, data tables, etc. into a copy of an existing program without this checksum problem?

Did I mention that I just started this job???

Offline, right click on the Program Files folder and click "Verify Project" (or it may say verify program...not sure...)

That should update the memory used fields even in the offline copy.

Also, be very careful with the words upload and download.

With A/B stuff, download means from the PC to the PLC/SLC and upload means from the PLC/SLC to the PC.

Anyway, you should be able to check the program size by verifying the project offline, and if your configuration matches the processor in use, it should allow you to DOWNLOAD if it isn't too big...

Paul

OkiePC said:

Offline, right click on the Program Files folder and click "Verify Project" (or it may say verify program...not sure...)

That should update the memory used fields even in the offline copy.

Click to expand...

See, that's when I'm getting my error. When I verify my program, it tells me I'm out of memory in the processor image.

Also, be very careful with the words upload and download.

Click to expand...

I didn't make that very clear in my original post, but we were trying to download the new program from the PC to the controller. That was when we first came across the out of memory error.

With A/B stuff, download means from the PC to the PLC/SLC and upload means from the PLC/SLC to the PC.

Anyway, you should be able to check the program size by verifying the project offline, and if your configuration matches the processor in use, it should allow you to DOWNLOAD if it isn't too big...

Paul

Click to expand...

Not to sound like a total fool, but if I look at the properties of the file in windows (since RS isn't helping me), that ought to be the same size as what goes to the PLC, right? If so, I should be undersized by about 6k.

My config should be good, it is set for the same PLC we have out on the line. I didn't write this program, but as far as I know, the maintenance guys just uploaded a program from the controller, saved it under a different filename, then started making their changes.

DEADMARSH said:

See, that's when I'm getting my error. When I verify my program, it tells me I'm out of memory in the processor image.

Click to expand...

Okay, then your SLC program is too fat...shrink some data files or cut out some ladder instructions...Of course, be careful not to delete stuff that's in use and don't completely trust the Usage button on the data monitor windows. There are situations in which it will tell you that data files aren't used but they really are...

DEADMARSH said:

Not to sound like a total fool, but if I look at the properties of the file in windows (since RS isn't helping me), that ought to be the same size as what goes to the PLC, right? If so, I should be undersized by about 6k.

Click to expand...

No, RSLogix adds your comments and a whole host of other information to the ladder file and probably compresses it before storing it on the PC. Most of my *.RSS files a much larger than the processor images they contain due to rung and address comments, custom data monitors, etc.

If RSLogix says it won't fit, then it has to be trimmed.

You can use the compare utility (under the Tools Menu) to compare the original uploaded file to the modified, and it will let you compare the data files and the logic to see where the fat was added and might be "trimmable". Once the utility compares the projects, you can view only the differences.

ST (string data) files are notoriously fat...each element is 80 bytes!

Good Luck!

Yup, yup, yup. You're exactly right. I've got too many words.

Whew, that I can deal with!

Thanks for your help! This site rules!