20
CP1484, CP1485, CP1486, CP3484, CP3485, CP3486
Data sheet V 1.00
1.1.17 Data / real-time buffering
The CPUs are equipped with a backup battery. The following areas are buffered:
•
Remanent variables
•
User RAM
•
System RAM
•
Real-time clock
Battery monitoring
The battery voltage is checked cyclically. The cyclic load test of the battery does not considerably
shorten the battery life, instead it gives an early warning of weakened buffer capacity.
The status information "Battery OK" is available from the system library function "BatteryInfo"
and the CPU's I/O mapping.
Battery change interval
The battery should be changed every 4 years. The change interval refers to the average life span
and operating conditions and is recommended by B&R. It is not the maximum buffer duration.
1.1.18 Changing the lithium battery
The CPUs are equipped with a lithium battery. The lithium battery is placed in a separate
compartment and protected by a cover.
Backup battery data
The product design allows the battery to be changed with the PLC switched either on or off. In
some countries, safety regulations do not allow batteries to be changed while the module is
switched on. To prevent data loss, the battery must be changed within 1 min. with the power off.
Model number
4A0006.00-000
0AC201.9
1 piece
5 pieces
Short description
Lithium battery, 3 V / 950 mAh, button cell
Storage temperature
-20 to +60 °C
Storage time
Max. 3 years at 30°C
Humidity
0 to 95 % (non-condensing)
Table 15: X20 CPUs - backup battery data
