These controllers include an RTC to provide system date and time information, and to support related functions requiring a real-time clock. To continue to keep time when power is removed, a non-rechargeable but replaceable battery is delivered with the controller. A battery LED indicates if the battery charge is low or the battery absent. For further details, please refer to Status LEDs.
The following table shows how RTC drift is managed:
|
RTC characteristics |
Description |
|---|---|
|
RTC drift |
Less than 30 seconds per month without any user calibration at 25°C (77°F). |
|
RTC drift with user logic assistance |
Less than or equal to 6 seconds per month with user calibration through application software when the controller is in RUN mode. |
The controller has one RTC battery.
In the event of a power outage, the backup battery will retain the time of the controller.
The table below shows the characteristics of the RTC battery:
|
Use |
In the event of a transient power outage, the battery will power the RTC. |
|
Backup Time |
At least 1.5 years at 45°C max (113°F). At higher temperatures, the time is reduced. |
|
Battery Monitoring Features |
Yes. |
|
Replaceable |
Yes. |
|
Controller RTC Battery Type |
Type BBCV2, Renata Type CR2477M. |
Installing and Replacing the RTC battery
While lithium batteries are preferred due to their slow discharge and long life, they can present hazards to personnel, equipment and the environment and must be handled properly.
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|
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EXPLOSION, FIRE, OR CHEMICAL BURNS |
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oReplace with identical battery type. oFollow all the instructions of the battery manufacturer. oRemove all replaceable batteries before discarding unit. oRecycle or properly dispose of used batteries. oProtect battery from any potential short-circuit. oDo not recharge, disassemble, heat above 100 °C (212 °F), or incinerate. oUse your hands or insulated tools to remove or replace the battery. oMaintain proper polarity when inserting and connecting a new battery. |
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Failure to follow these instructions will result in death or serious injury. |
To install or replace the RTC battery, follow these steps:
|
Step |
Action |
|---|---|
|
1 |
Remove all power from your controller. |
|
2 |
Slide out the battery holder of the controller: 
|
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3 |
Remove the battery from the battery holder: 
|
|
4 |
Insert the new battery into the battery holder in accordance with the polarity markings on the battery: 
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|
5 |
Replace the battery holder on the controller and verify that the latch clicks into place. |
|
6 |
Re-apply power to the Modicon LMC058 Motion Controller. NOTE: If you do nott apply power to the Modicon LMC058 Motion Controller immediately, the external backup battery life might be significantly reduced. |
|
7 |
Set the internal clock. For further details on the internal clock, please refer to RTC Library. |
NOTE: Replacement of the battery in the controllers other than with the type specified in this documentation may present a risk of fire or explosion.
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|
|
IMPROPER BATTERY CAN PROVOKE FIRE OR EXPLOSION |
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Replace battery only with identical type: Renata Type CR2477M. |
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Failure to follow these instructions can result in death, serious injury, or equipment damage. |
