Siemens SIMATIC S5 CP 523 Manual page 45

CP 523
4.1.3 Clock Test
The module's real-time clock is tested. The clock is set when the battery back-up fails during PLC
POWER OFF. The clock has the default setting 12:00:00 01.01.90.
Errors and the default setting are provided an appropriate number in byte 0 "Module status" and
can be evaluated in the control program.
Error Number in
Byte 0
1X
H
2X
H
X : may assume different values
4.2 Performance during Operation
You must note the following if you want to modify the configuration during operation:
• The CP 523 may be plugged in or unplugged only when the power is switched off.
• The memory submodule may only be plugged in or unplugged when the power is OFF.
• To guarantee trouble-free printing, make sure the 25-pin subminiature D female connector is
only unplugged when the CPU is in STOP mode and data transfer between the CP and the
printer has been completed.
When the power is switched off, the battery provides backup for the clock data.
EWA 4NEB 811 6044-02a
Table 4-3. Clock Test Errors
Message
Clock defective
Clock set
Default setting
Remedy
Replace module
Transfer the correct time to the CP with the
programmer "FORCE VAR" Junction
Notes on Operation
4-3