Sinumerik Alarm 2102 NCK battery alarm

Sinumerik Alarm 2102 NCK battery alarm

The under voltage monitoring (2.4-2.6V) of the NCK battery was detected during system power-up.

– The NC switches to follow-up mode.
– NC not ready.
– Channel not ready.
– NC Start disable in this channel.
– Interface signals are set.
– Alarm display.
– NC Stop on alarm.

Please inform the authorized personnel/service department.Pull out the battery/fan unit from the NC module and replace the battery (type: lithium battery with lead, size 1/2AA, 850mAh, min. 3.2V).
The system must then be reinitialized because it must be assumed that data has been lost in the buffered RAM during the last power-off phase as a result of insufficient supply voltage (refer to Section 2.2 in the Installation and Start-up Guide for the procedure).
The following data might have been corrupted or entirely lost:
• NC machine data
• Drive machine data
• Option data
• Setting data
• User variable
• Global subroutines
• Cycles and macros, as well as
• PLC machine data
• PLC basic program
• PLC user program, and all
• PLC user data.
User data in the NCK and PLC (e.g. tool and work piece data) that have been altered by the manufacturing process since the last data backup must be updated manually to match the present machine status!

Program Continuation:
Switch control OFF – ON.


  1. Siemens Diagnostics Guide by Siemens
Sinumerik Alarm 2102 NCK battery alarm