Siemens SIMATIC S5 Manual page 318

– Start the self-tuning function or correct and optimize parameters (see
Programming Instructions for FB 244, FB 162).
If the self-tuning function does not determine any parameters, check the
minimum requirements of the controlled system and the setpoint step.
– Store corrections
– Operation
c ) Checking the back-up of the RAM chip
(This note is only for servicing and is not required for normal operation)
"Test code" to read out the back-up identifier and the CMOS test pattern
(valid from module 21 onwards).
DB - A:
Transfer the codes with the command "KS", "PA", "AE (controller 14)" or
"AS (controller 14)". In addition to this, at least one controller must have a
sampling time longer than the minimum possible sampling time on the IP.
Result:
The result is entered in DB-C with the command "IW (message 21)"
DB-B:
Explanation:
If PLC requests a cold restart, the back-up identifier is 2222. Every 50 to 80 ms
a check is carried out to make sure that the CMOS test pattern is still OK. If the
pattern is not OK, the identifier is set to CCCC.
Otherwise, the identifier is only updated after power up. It may be 0000 briefly,
otherwise, it is 1111 if there is no error. If the test patterns are not OK after
power up, the identifier is set to 5555; if the U
incorrect, the identifier is AAAA. Copies of the four test patterns as they were
when the power was switched on are indicated in DW 113 to DW 116 of DB-B.
IP244
C79000–B8576–C863–02
DW 245 KY = X,25
DW 246 KH = 1FF0
DW 112 KH:
DW 113 KH:
DW 114 KH:
DW 115 KH:
DW 116 KH:
Checklist for Start-Up
back-up identifier
copy of the 1st test pattern
copy of the 2nd test pattern
copy of the 3rd test pattern
copy of the 4th test pattern
scan following power up is
batt
8–7