Changing the Atrium RAM memory backup battery
(Original Document)
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At a Glance
This battery on the Atrium processor module ensures that the processor internal RAM memory and the real-time clock are saved in the event of a power outage. It is delivered in the same packaging as the processor and must be installed by the user.
NOTE: With an Atrium processor, there is no point in putting a battery into the rack power supply which usually houses the processor (rack with address 0).
Installing the battery for the first time
To install the battery, carry out the following:
Step
Action
1
Remove the cover by squeezing the sides.
2
Put the battery in its slot taking care to observe polarities.
3
Replace the cover which keeps the battery in its slot.
Changing the battery
The battery can be changed every year as a preventative measure or when the BAT LED is lit. However the LED is not visible when the PC is closed, but you have a %S8 system bit which can be used by the application program to generate an alarm to warn that the battery needs changing.
To change the battery, carry out the following:
Step
Action
1
Switch the PC off.
2
Disconnect the different cables linked to the processor.
3
Open the PC.
4
Take the card out of its slot.
5
Remove the cover.
6
Remove the defective battery from its slot.
7
Put in the new battery, observing the polarities.
8
Replace the cover.
9
Put the card back in its slot, close the PC, connect external components and switch on.
CAUTION
LOSS OF RAM DATA
Changing the battery should not exceed the stated limit for the PC being switched off. Exceeding this limit may cause data in RAM memory to be lost.
Failure to follow these instructions can result in injury or equipment damage.
Illustration
Installing the battery on the TSX PCI 57:
How often must the battery be changed?
Period of battery backup
The length of time during which the battery ensures backup of the processor’s internal RAM memory and the real-time clock depends on two factors:
Summary table:
Ambient temperature when inoperative
≤ 30°C
40°C
50°C
60°C
Backup time
PLC off for 12 hours per day
5 years
3 years
2 years
1 year
PLC off for 1 hour per day
5 years
5 years
4.5 years
4 years
Independent saving by the processor
The processors have their own offline independent save function to save the processor internal RAM memory and the real-time clock, which allows the removal of:
The backup time depends on the ambient temperature.
Assuming that the processor was switched on previously, the guaranteed time varies in the following way:
Ambient temperature when switching off
20°C
30°C
40°C
50°C
Backup time
2h
45mn
20mn
8mn