Rockwell Automation 1771-DB Basic Module User Manual - Series A - Manual (Page 23)

Installing the BASIC Module
Chapter 3
3–9
Electrostatic discharge can damage integrated circuits or semiconductors in
this module if you touch backplane connector pins. It can also damage the
module when you set configuration plugs and/or switches inside the
module. Avoid electrostatic damage by observing the following
precautions:
Touch a grounded object to rid yourself of charge before handling the
module.
Do not touch the backplane connector or connector pins.
If you configure or replace internal components, do not touch other
circuit components inside the module. If available, use a static-safe
work station.
When not in use, keep the module in its static-shield bag.
CAUTION: Electrostatic discharge can degrade performance
or damage the module. Handle as stated above.
The 13 K bytes of user RAM and the clock/calendar are battery backed.
Drain on the battery should be less than 0.5 mA DC during battery back-up
(no power) and less than 50 uA while the module is powered. Battery life
during no-power conditions is about 2000 hours. Battery shelf life is about
20,000 hours. When the BAT LOW indicator comes on the battery should
maintain the clock and program data for about three days. We recommend
immediate replacement.
To replace the battery (figure 3.4):
1. Place a screwdriver in the battery cover slot.
2. Press inwards slightly.
3. Rotate the screwdriver and battery cover counterclockwise 1/4 turn.
4. Release the pressure and remove the battery cover.
5. Replace the battery with the positive (+) terminal out.
6. Replace the battery cover.
3.4.1
Electrostatic Discharge
3.5
Battery