X20 system modules • X20 CPUs • X20CP158x and X20CP358x
X20 system User's Manual 3.10
931
4.12.3.19 Data / Real-time clock buffering
The CPUs are buffered by 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.
Replacement interval for battery
The battery should be replaced every 4 years. The replacement intervals recommended by B&R reflect the batter-
ies' average service life and operating conditions. It does not represent the maximum buffer duration.
4.12.3.20 Exchanging the lithium battery
The CPUs have a lithium battery. The lithium battery is found in a separate compartment on the bottom of the
module and protected by a cover.
Backup battery data
Model number
4A0006.00-000
0AC201.91
1 pcs.
4 pcs.
Short description
Lithium battery, 3 V / 950 mAh, button cell
Storage temperature
-20 to 60°C
Storage time
Max. 3 years at 30°C
Relative humidity
0 to 95%, non-condensing
Table 294: X20 CPUs - Backup battery data
Important information about the battery exchange
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.
Warning!
The battery must be replaced by a Typ CR2477N Renata battery only. The use of another battery may
present a risk of fire or explosion.
The battery may explode if handled improperly. Do not recharge, disassemble or dispose of in fire.
Summary of Contents for X20 System
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