Siemens s7-300 Programming Error

Hi All,

I am trying to figure out where my programing error is in the program. The Diagnostics Buffer says Event ID 16#2522.
The help tells me what this error is, trouble is I can't find any values outside or not completely within the permitted address range.
The Event is;
Event 3 of 10: Event ID 16# 2522
Area length error when reading
Global DB, word access, Access address: 34
Requested OB: Programming error OB (OB121)
Priority class: 1
Internal error, Incoming event

I'm assuming 'Global DB, word access, Access address: 34'
is where the error is but I don't know where this is in my program.

Any ideas how to overcome this?

Cheers

sounds like you have a DB thats too short. It should tell you which block the error is seen in, in one of the diagnostic messages.

Alternatively try putting a trap in OB1 to see where the error is, the error can be found in the TEMP area of OB121.

Be aware if you want the PLC to continue to stop on error after putting code in OB121, you would have to call SFC46.

Area length errors are usually the result of indirect addressing which has gone wrong.

If you remove OB121, you force the CPU to stop.
Then you can investigate the diagnostics - B stack. This tells you where in the program the error occurred. I think that there is even a "go to" button that will open the last block at the correct spot.