Siemens SIMATIC S5 Manual page 340

PLC Error Messages
Error Con-
Error Message Text
Identi- sec.
fier No.
Progr.
251 01
Output image in A different
to B: CPU or PL error
Additional info. 1:
AQ word No.
Additional info. 2:
AQ value in A
Additional info. 3:
AQ value in B
251 02
FB251 call with wrong
parameters:
Programming error
B-80
Possible Cause
Error group No. 20
Word address at which output
images of A and B differ, decimal
display
Output value of the AQ module in
subunit A, hex display
Output value of the AQ module in
subunit B, hex display
Error group No. 12
- Substitution error
S5-115F Manual
Remedy
- Replace CPU
- Replace PL
- Service
Warm restart:
1. POWER OFF/ON
2. Stop/Run
- Correct the actual FB251 call
parameter (analyze ISTACK)
Warm restart:
1. Stop/Run
EWA 4NEB 811 6149-02