Siemens S5 OB's

Hello,

i have a problem that a Siemens S5 115u 928b CPU goes to Stop mode.
The only thing I can do to restart is fully erase it and reload the program. To make sure it's not a fault in my program I thought I could program an OB that is called when a programming fault occurs.

In S7 I know this is OB121, anyone an idea this is possible in S5?


Thanks,

Jeroen Benoot

OB's available in CPU928B for handling errors:
OB19 - call of not programed block,
OB23 - timeout during direct access to IO module,
OB24 - timeout during update of IO image,
OB25 - adressing error,
OB26 - scan cycle timeout,
OB27 - substitution error,
OB29 - operation error,
OB30 - parameter assignment error,
OB31 - other execution errors,
OB32 - transfer errors for data blocks,
OB32 - collision of cyclic interrupts,
OB34 - error in PID controller processing.

thanks

If you check the Istack this will tell you why & where it fell over

it will tell you the block it stopped on the address after the fault & what caused it, if you load the program & it runs again I suspect that somewhere in the program there is a pointer stored in a DB that calls a word beyond the length of the block or indirectly trying to access I/O that does not exist, this occurs when people do not put traps in the code to stop a pointer incementing beyond a DB length or I/O.