S7 error

[douyi]

I got a red light in CPU which is SF. What's that? How can I debug that kind of error?

Thanks

 

[jacekd]

System Error.
In SIMATIC Manager window select a CPU icon. Press ctrl-D and go to a Diagnostic Buffer bookmark.

 

[Werner]

Try running without user program (no calls in OB1). If the SF led switches off you have a software problem you need to fix. If you don't understand the Siemens Diagnostic buffer messages you can test the software by adding youre program step by step. (If possible for you're application).

If you found the block with the error you can exit the block with an BEU. This helps you find the problem inside the block (by shifting the BEU. Start half way -> SF Led on then problem before BEU otherwise beyond the BEU etc....)

 

[SimonGoldsworthy]

I would recommend NOT using BEU's. Create a flag called "I_Need_Fixing" (say M1.7). When you want to do exit a block early, use

A M1.7
ON M1.7
BEC

When you have finished, do a search on M1.7 and you can then remove all your testing without leaving any BEU's behind to trip you up.
Also, do not comment out code, but jump around it.

 

[Werner]

I would recommend NOT using BEU's. Create a flag called "I_Need_Fixing" (say M1.7). When you want to do exit a block early, use

A M1.7
ON M1.7
BEC

When you have finished, do a search on M1.7 and you can then remove all your testing without leaving any BEU's behind to trip you up.
Also, do not comment out code, but jump around it.

I did not mean leaving them in! Only to find the problem in the first place. What you mean is a reminder bit. I also use this to know what I still have to do. Most of the time I create a local temporary indication the work still to do. Like "Conveyor empty", I know I have to make some kind of flag indication an empty conveyor.

It is my experience that errors are found very quick using this instruction.

 

[scimdarren]

Similar problem

Hi
I have an SF and a flashing BF, looking on the diagnostic buffer, I dont see any points for concern.

What is SF?
What is a flashing BF?

Darren

I did not mean leaving them in! Only to find the problem in the first place. What you mean is a reminder bit. I also use this to know what I still have to do. Most of the time I create a local temporary indication the work still to do. Like "Conveyor empty", I know I have to make some kind of flag indication an empty conveyor.

It is my experience that errors are found very quick using this instruction.

 

[Werner]

BF=Bus failure
SF=System failure

BF > profibus nodes are not connected or in error or something simulair
SF > Configuration error or rack failure or program failure or ....

 

[scimdarren]

Ok many thanks, I should have realised, I have set up 5 micromaster 420's in the HWConfig, but the PLC is not connected or addressed to them. Is the 'SF' likely to clear as well once comms established with the Profibus?

Darren