Make a data backup before changing the buffer battery.(included PLC memory !!!)
When exchanging the buffer battery, remember:
Switch off the machine and the TNC 640.
The buffer battery may be exchanged only by trained personnel.
When exchanging the buffer battery, ensure electrostatic discharge
protection. Improper handling can result in damage to the components or
assemblies due to ESD!
To exchange the battery:
The buffer battery is on the main board of the MC
Loosen the screws securing the rear housing cover of the MC
Remove the cover
The buffer battery is located on the upper edge of the PCB.
Battery type: 1 lithium battery, type CR 2450N (Renata), ID 315878-01


Exchange the buffer battery; the new battery can be inserted in only one
position.