Something for anyone going online with a PLC5 to remember:
I just had an experience when trying to do some online edits to a PLC5-30 some edits handled themselves properly, but some reported an Access Violation and RSLogix went offline. To go back online I had to upload the program to be able to go online as it no longer matched. (I did have a full copy with all comments and descriptions) Once when I went back online after this happened the line I was trying to edit was no longer in the PLC!
I decided to make the edits offline then download the full program - and also to change the BAUD from 2400 to 19200 (big difference!)
When I verified the program I finally got the correct error: The PLC program consisted of 7 words more than the PLC memory. The PLC was absolutely full. (It is a large program running many pumps, heaters, 40 electroplating rectifiers and 2 hoists with an iFix HMI)
I went through the program looking for anything I could reduce and found contrary to what I thought, a branch uses more memory than another rung. Some rungs did unconditional math & moves every scan, up to 20 branches per rung, and each branch I split off to a new rung opened 2 words of memory. I was able to open almost 80 words, made the edits needed, now have some free memory and a lot faster Comm's.
I know there are still a lot of PLC5's out there so I thought I would pass along this experience.
I just had an experience when trying to do some online edits to a PLC5-30 some edits handled themselves properly, but some reported an Access Violation and RSLogix went offline. To go back online I had to upload the program to be able to go online as it no longer matched. (I did have a full copy with all comments and descriptions) Once when I went back online after this happened the line I was trying to edit was no longer in the PLC!
I decided to make the edits offline then download the full program - and also to change the BAUD from 2400 to 19200 (big difference!)
When I verified the program I finally got the correct error: The PLC program consisted of 7 words more than the PLC memory. The PLC was absolutely full. (It is a large program running many pumps, heaters, 40 electroplating rectifiers and 2 hoists with an iFix HMI)
I went through the program looking for anything I could reduce and found contrary to what I thought, a branch uses more memory than another rung. Some rungs did unconditional math & moves every scan, up to 20 branches per rung, and each branch I split off to a new rung opened 2 words of memory. I was able to open almost 80 words, made the edits needed, now have some free memory and a lot faster Comm's.
I know there are still a lot of PLC5's out there so I thought I would pass along this experience.