5
5-8
PG 720 Programming Device
C79000-G7076-C720-02
5.4
Replacing the Back-Up Battery
A back-up battery (3.6 V lithium battery) powers the real-time clock even
after the PG 720 is switched off. In addition to the time of day, all the
information about the PG 720s configuration is stored in RAM. If the
back-up battery fails or is removed, all this data is lost.
The clock uses very little power and the lithium battery has a high capacity
so that the battery can provide back-up power for the real-time clock for
many years and seldom needs to be replaced.
If the battery voltage is too low, the time of day and the device configuration
data in the RAM are lost.
In this case, you must replace the back-up battery. The battery is located
below the drive mounting.
Figure 5-5
Screws Securing the Drive Mounting
Battery Power
Supply for
Real-Time Clock
and Configuration
Battery Voltage
too Low
Replacing the
Battery
PG 720 Expansions
Содержание SIMATIC PG 720
Страница 32: ...3 3 18 PG 720 Programming Device C79000 G7076 C720 02 Getting to Know the PG 720 ...
Страница 56: ...4 4 24 PG 720 Programming Device C79000 G7076 C720 02 Installing the PG 720 ...
Страница 76: ...6 6 10 PG 720 Programming Device C79000 G7076 C720 02 Configuring the Programming Device ...
Страница 80: ...7 7 4 PG 720 Programming Device C79000 G7076 C720 02 Error Diagnostics ...