Siemens simatic hmi op7 Equipment Manual page 136

16.4 Optional Backup Battery for the OP17
Function
Source of supply
Lifetime
Installing the
battery
16-8
You can upgrade the OP17 with an optional backup battery. When the power
supply is interrupted, the backup battery ensures that
the operating data in the OP17 message buffer are retained and
the hardware clock continues to run on its internal reserve power.
You can obtain the backup battery from the Siemens spare parts service. It is
shipped ready for installation with a cable and a plug connector. Please refer
to our ST80.1 catalog for the order number.
Under normal operating conditions, the battery has a typical lifetime of
approximately four years. The discharge degree of the battery is not moni-
tored by the OP17.
To install the battery, proceed as follows:
Step
1 Remove the cover of the battery compartment at the rear of the
OP17.
2 Insert the battery into the holding fixture. The snap-in plastic
supports hold the battery in its compartment.
3 Insert the plug connector on the battery lead in the two-pin plug
connector above the battery compartment. The plug connector is
coded and is thus protected from accidental polarity reversal.
4 Stow any excess length of lead in the battery compartment and
close the compartment again.
Procedure
Equipment Manual OP7, OP17
Release 04/99