This could be a tricky one...

Periodically, the online program(in the PLC)is backed up: via chart readback(all parameters), compile and download(changes only) in CFC Editor.

After all PLCs were 'backed up', the offline project contains the most up to date data and is zipped.

On this occasion, the backup operation was performed and, let's just call the backup as BACKUP.ZIP. Some time later, changes were made to one of the PLCs (call it PLC1). Some FBs were added to one of the CFC chart. That worked fine. Next, there was some other modifications to be made. The whole project directory was first copied to another directory to keep a copy of the modified project in ..\duplicate.

The modification was made and was unsuccessful and a restore have to be made. UNFORTUNATELY, backup.zip was restored. Worse still, the above backup operation was due and was performed.

Now, all PLCs were successfully backed up except for PLC1. At this moment, PLC1 contains a newer version of program within the PLC, but the offline version is the version before the changes were made. Hence, I cannot simply do a readback compile and download changes only. CFC Editor only allow 'Complete download'... all OBs, FBs, FCs, DBs...etc have to be first deleted...
I also cannot restore the copy of the modified project now because all other PLCs have been updated.

Confused?
PLC1: Online prog matches that in the '\duplicate' directory.
All other PLCs: Online prog matches that in the current project folder.

Question now is: How do I get the online and offline PLC1 information to match each other?

I want the offline version in the current project folder to match that in the PLC itself. I have talked to Siemens tech support and, going into PLC STOP and do a complete download seems like the only solution. But that is not what a continuously running plant can afford!

Has anyone been in the same situation before?
Suggestions, ideas, references, help, all welcomed.

Many thanks.

 

Maybe there is something that I do not understand about this problem.

Here is what I did.

I took a working program and did a "save as" to get a second copy of my application.

I then added a cfc and a cfb to the orginal program and then compiled and downloaded.

I next tried to go online with the old or saved program. Cfc told me that I needed to do a full download.

I next opened the "component" view of the old and the new project.

I went to the "program" associated with the modified application and executed a copy.

I then went to the "saved" version and did a paste. Simatic manager asked me if I was really sure that I wanted to do this and I answered yes.

The copy took place and I was told that message numbers would be re-assigned. I agreed that that would be ok with me.

The copy completed. I then opened the new version of the old application and went on-line. The cfc editor had no complaints.

Maybe I missed something here. Just because the projects has multiple cpus should not stop one from doing a copy and paste to an individual cpu.

If I am way out in left field on this then I am sure I will hear about it.

 

SW: Thanks For the reply, John.
After the new version of the old application is copied and, there is no problem going online. Have you then tried to download that chart onto the PLC? There is doubt that the time stamp difference will not allow download of changes only.

Any idea/comments?

 

After you replied I started from scratch and walked through it once again. Since I am using PlcSim, I also saved the image of the cpu so that I could close it and reopen it after I finished the copy.

I did the copy. Went online. Did an incremental download. Closed the plcsim. Reopened it again. Went on-line. and then did another incremental download. It worked.

I once had a program crash during a startup and could no longer compile and download. My colleagues at CCA recreated my program for me overnight from old pieces. The next day we were back compiling and downloading without having to do a full download.

I will not take a definitive stand here but it works for me. I have done about six PCS 7 projects now and have never had to shutdown a system with the corresponding loss of product or production.

I think you can get back to where you need to be without a full download.

John