PLC5 quirks

We have several PLC5 530 processors. We can view the online file on a laptop running ver 7.30 Rslogix 5. We have another file open on the laptop, thats basically identical to the online file. Includes same processor name different checksum though becasuse we made a change....Now heres the quirk...If I stay online with the laptop and open up another session of RSlogix 5 and open up a new file and then select run mode with the offline file, the offline file will go onlne with both files....its very strange...there is not even a prompt to say that the offline file doen't match the online file and please select a file...both files show that there both in run!!!!

Rockwells explanation is logical, and the behaivior they explain for file selection and checksum generation and determination appear to have always worked in the past (at least what I experienced seeing), but what blows away Rockwells expalnation are two things that happen...

1). We had the file located on our desktop not in the Project File Search Path as Rockwell noted to do , and we still were able to load the offline file.

2). We made a change to the offline file and left it open... which should have altrered the checksum value, so now we have a file with the same porcessor name but different checksum....(also note the file was not in the Project FIle Search Path but on the desktop)...as the Rockwell rules stated

Anyone else experience the same?

jimdi4 said:

2). We made a change to the offline file and left it open... which should have altrered the checksum value, so now we have a file with the same porcessor name but different checksum....(also note the file was not in the Project FIle Search Path but on the desktop)...as the Rockwell rules stated

Click to expand...

I believe that the checksum will not be updated in the offline file until you verify the program. Right click on the folder "Program Files" and click verify program, to see if that changes the checksum, and the behavior of the software when you go online.

Also, if the file is already open when you click "Go Online", it will be checked for a match even if it is not located in the search path.

Once online, the ladder logic on the screen will match what is in the PLC, and the data table values will be updated as needed (as you open a window and view the data). So, it is possible to see bogus numbers when you first scroll through the ladder or open a data table, and then they will "suddently" get corrected as the software reads them from the PLC.

Here's the kicker...We even tried a file with a totally differernt processor name and checksum...and then what happened is the offline file...with a totally different processor name and checksum went online and became the online file!!

It must be the fact that the other instance of RSLogix 5 (which is already online) is affecting what files are used when the 2nd instance goes online.

Does the 2nd instance (with a different checksum and processor name) show you incorrect logic or data?

OkiePC said:

Does the 2nd instance (with a different checksum and processor name) show you incorrect logic or data?

Click to expand...

Nope...it takes on exactly what the online file is...So it appears the online file sucked up the offline file and then just kept executing the original file in the processor....What we did as a "get around" was we deleted all of the offline file on the laptop..that had the same name as the online filename...which makes no sense because a totally different filename with different checksum and processor name should have not even been allowed to go online because the files don't match....

We even tried this with a totally different laptop just copying the file over with its own install of RsLogix 5 and completely different RS linx and it did the same thing...

So what we discovered is that by deleting any instance of the original file on the hardrive which "points" to the same "checksum" and "processor name" regardless of the "filename" seemed to have allowed at least the "prompt for
correct file" (Search for offline Image) to occur...Very strange...

Try it...first load the PLC 5 with a file for simplicity cal it file A....Then go online...Open up another RSlogix 5 session then open up file B....Then then attempt to go online with file B...It will go online with file B and the filename on-top toolbar will change to the File A name and both sessions with be in run mode and both will show file A at the top toolbar...this may have existed for a long time with RSlogix 5 but we discovered it here accidentally while someone was doing a program validation