S5-95F
Design, Functions and Operation
Automatic Reset
The S5-95F executes an automatic reset when the memory submodules are replaced by memory
submodules of different type or size.
When the programmable controller executes an automatic reset, the following data is retained:
•
Programmer bus number
•
Clock data of the integral real-time clock
•
Internal system backup data (e.g. Safety procedure after power failure)
•
System event DB
•
System ID number
2.5.5 Function of the Backup Battery
A backup battery is absolutely necessary for S5-95F operation. If the power fails or if the subunits
are switched off, the contents of the internal RAM are retained.
The S5-95F monitors the status of the battery. If the battery charge drops below a permissible value
during operation, the operating system sets a bit in the system event DB; OB34 is then called prior
to each scan cycle. If the battery is not replaced within 72 hours after this message, the S5-95F
goes to STOP.
If one battery is missing or if the battery charge drops below a permissible value, you cannot switch
the S5-95F to the RUN mode after a power OFF/power ON sequence.
Replacing the Backup Battery
Do not wait until the S5-95F indicates that it is time to change the battery, simply replace it every
year as a preventive measure.
Safety Note
Battery replacement in the RUN mode is not permissible for systems under the authority
of the German Statutory Industrial Accident Insurance Institution (BG) or the BG Institute
for Industrial Safety (BIA). In all other systems you must observe the ESD guidelines
when replacing a battery in the RUN mode.
Disposal of Backup Batteries
!
Warning
Do not charge lithium batteries. They could explode. Dispose of used batteries properly.
EWA 4NEB 812 6210-02
2-19
