Don't cry.  Please check my attached 2 pages cutting from Function description part-1 Basic --"R1" reference 

don't worry about serial number, try to make encoder calibration 

possible need to read the whole section "R1"

Ccnservice

Hello,

Problem with  Sinumerik 840d with ncu 573.2 after replace absolute encoder Heidenhain LC181.

 Where to enter new serial number?

MD34230 without encoder keeps the old serial number

With new encoder becomes 0.

we read all the instructions, asked all the people who deal with siemens and nobody knows 

Best regards,

   Cncservice