Omron CJ - 09-2009 Operation Manual page 581

Programmable controllers

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Replacing User-serviceable Parts

Low Battery Indicators

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.

Memory Backup Time

If the PLC Setup has been set to detect a low-battery error, the ERR/ALM

indicator on the front of the CPU Unit will flash when the battery is nearly dis-

When the ERR/ALM indicator flashes, connect a Programming Console to the

peripheral port and read the error message. If the message "BATT LOW"

appears on the Programming Console* and the Battery Error Flag (A40204) is

ON*, first check whether the battery is properly connected to the CPU Unit. If

the battery is properly connected, replace the battery 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. 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.

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 Programming Console and the Battery Error Flag

(A40204) 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.

CJ1H-CPU@@H-R

This graphic is for reference only.

Section 12-2

Ambient temperature

Chapters

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