Step7 - Errors when recompiling in HWConfig

Panic stations - the production line's been down for over two hours and I can't reload the System Database!

To go back to the start - I needed to add a connection to one of the PLCs and initially had problems with compiling in NetPro because the MPI and Profibus Networks had the same addresses. I cleaned that up but still got an undefined error, however I decided to continue, thinking I could just go back to the backup if something went wrong.

I was wrong - the screwed-up System data landed the PLC in a state where it neither goes into RUN nor into STOP. Going back to the backups didn't help they also give the undefined error. According to the Help files one of the problems can be that the "S7tmp" directory is write protected and it was. However removing the write protection didn't help and on the next attempt the write protection was back again.

Has anybody any idea how I can get a clean System DB loaded onto the PLC?

Just for completeness, here's the Help file.

And here's the culprit,I hadn't spotted this detail at first, but it still doesn't mean much to me!

RMA said:

Has anybody any idea how I can get a clean System DB loaded onto the PLC?

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Do you have a previous backup with a reasonably uptodate HW config ?
If so, I would start with that.

Is it an S7-400, or an S7-300 ?
If it is the first you probably have to clear the memory.
If it is the latter, you probably have to load a fresh new MMC to clear it completely.

If you can load the HW Config from the previous project, you can load the program (without the SDB) from the latest backup.

It's a 315-2 DP with MMC.

I've tried clearing the memory, but that didn't help. I've even gone back to backups before I started working with the project, but I get the same error on compiling. Unfortunately, it doesn't look as if it's possible to download the system data without first compiling.

I'm beginning to wonder whether the problem may lie with the copy of Step7 on my laptop, I'll have to see if I can dif up another PC to try from.

I've got a new MMC, but I'm a bit hesitant to use it until I get rid of the compile fault, in case I land in the same state again.

I've now tried it out on another PC using the backup from last November and get exactly the same result (and error message). So it doesn't look as though the problem lies with my Step7 installation.

What now?

I've tried clearing the memory, but that didn't help. I've even gone back to backups before I started working with the project, but I get the same error on compiling.

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So it is a project that you received from someone else. Maybe it was corrupted allready, but until now you didnt have to download the HW Config.
Or, there is a component in the HW config that doesnt exist in your HW catalog. But I dont think that this will cause this kind of error. And often, STEP7 can automatically import components from projects.

btw I PM'ed you.

edit: One problem according to the help text is that you dont have all the required optional packages. Unfortunately, I dont know how you can remove a function or option for which you dont have the software package (catch-22). One way could be to recreate the HW config from scratch.

Maybe it was corrupted allready

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It was - but now I've got a clean backup from Feb 2005(!). Just need to patch the bits and pieces together now - I hope!

Get on the line with Siemens Tech Support, find someone with a clue, and beg them for the "Secret Key Combination" that fixes errors with the hardware config.
I had that same problem, and it ended up (after Siemens tech had me reinstall all software, clear memory on the CPU, and other junk for 3 days) that the only solution was the secret key-combination.

@rdrast - thanks for that suggestion, it may well come to that. By the way, which post was it where you mentioned what you thought the combination might be. I can't find it now.

Current state of affairs is that after downloading the System database from the Feb 2005 backup with a clean MMC the PLC finally came back up in RUN. Unfortunately, the Beckhoff Profibus Terminal Block has disappeared when online (the other 7 or 8 DP slaves are all OK).

Since that's really a separate problem, I think it's probably better dealt with in a separate Thread.

The S7tmp file being protected: It isn't, it's a WinXP bug, it just looks protected.(just like every other file in the folder looks protected)
Had the exact same problem on one of our PG's. Happened we just got Step 7 5.4, so upgraded and problem was gone. What caused this error is still a mistery.
If you have a back up that hasn't been on the defective laptop, try it on another pc, see if it compiles. When copying from defective to another it somehow corrupts the project.

Have you tried just downloading the SDB file from the blocks folder instead? That way you can download the hardware configuration without needing to do a compile.

RMA said:

@rdrast - thanks for that suggestion, it may well come to that. By the way, which post was it where you mentioned what you thought the combination might be. I can't find it now.

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9) DOCUMENT HIDDEN COMMANDS. It took three days once of trying to get a simple analog module to accept configuration changes, before a Siemens Tech Support person finally told me to just try hitting some wierd key combination (something like CTRL-ALT-SHIFT-F8), which magically forced the hardware config to work properly.

This is in the Step 7 wishlist from JesperMP

Thanks Werner, I can maybe try variations on the theme!

The magic code!

Just to finish off this Thread, I finally got the magic code from Siemens, but they asked me not to spread it around too much, so I don't think it would be fair to post it openly.

Should anybody ever be in need of it, just drop me a PM and I'll pass on the magic combination.

Cheers

Roy