Omron CP1H-CPU - 05-2006, Operation Manual

Page: 516 / 669

485
Replacing User-serviceable Parts
Section 10-2
Note The minimum lifetime is the memory backup time at an ambient temperature
of 55
°
C. The typical lifetime is the memory backup time at an ambient temper-
ature of 25
°
C.
Low Battery Indications The ERR/ALM indicator on the front of the CPU Unit will flash when the bat-
tery is nearly discharged.
When the ERR/ALM indicator flashes, connect the CX-Programmer to the
peripheral port and read the error messages. If a low battery message
appears on the CX-Programmer (see note 1) and the Battery Error Flag
(A402.04) is ON (see note 1), first check whether the battery is properly con-
nected to the CPU Unit. If the battery is properly connected, replace the bat-
tery as soon as possible.
Once a low-battery error has been detected, it will take 5 days before the bat-
tery fails assuming that power has been supplied at lease once a day (see
note 2). Battery failure and the resulting loss of data in RAM can be delayed
by ensuring that the CPU Unit power is not turned OFF until the battery has
been replaced.
Note 1. The PLC Setup must be set to detect a low-battery error (Detect Low Bat-
tery). If this setting has not been made, the BATT LOW error message will
not appear on the CX-Programmer and the Battery Error Flag (A402.04)
will not go ON when the battery fails.
2. The battery will discharge faster at higher temperatures, e.g., 4 days at
40
°
C and 2 days at 55
°
C.
Memory Backup Time
Ambient temperature
This graphic is for reference only.
5 yr
4 yr
3 yr
2 yr
1 yr
CP1H CPU Unit
25
°
C
40
°
C
55
°
C
ERR/ALM indicator