Siemens Module Information - Diagnostic Buffer

I have been given code to put in a machine. I didn't write the code and there is quite a bit in german and STL which I'm not very comfortable with yet. When part of the code is run the PLC goes into stop mode. I get this info. I see where it tells me what FB is the problem, is there something that will tell me which network or line is the issue.


Event 1 of 500: Event ID 16# 4562
STOP caused by programming error (OB not loaded or not possible, or no FRB)
Breakpoint in user program: Cyclic program (OB1)
Priority class: 1
FB number: 1204
Module address: 65535
Previous operating mode: RUN
Requested operating mode: STOP (internal)
Internal error, Incoming event
01:30:16.066 PM 05/06/2010

Event 2 of 500: Event ID 16# 2523
Area length error when writing
Global DB, word access, Access address: 138
Requested OB: Programming error OB (OB121)
OB not found, or disabled, or cannot be started in the in the current operating mode
Internal error, Incoming event
01:30:16.061 PM 05/06/2010

I'd say the issue is hardware or addressing. It looks like FB1204 is attempteng to address a module at diagnostic address 65535. If that module is offline or unavailable, and there's no information in OB81/82/83 to handle this error, it requests the CPU to go to STOP.

A missing or offline or mis-addressed module would also explain the "area length error when writing" in message #2.

FB1204 is writing to DBW138 in the currently open global DB, but the DB is not long enough. The I stack gives info on the currently open DB's etc.

Thanks for the info that helps a lot.

I just read up on the I stack last night but couldn't see it since I wasn't at the machine.