The M580 PLC serial number can be read in Unity Pro using %SW135 to %SW137 system words.

These words contain the serial number of the M580 PLC (correspond to the S/N written on the module itself):
%SW135: the Serial Number - high bytes
%SW136: the Serial Number - middle bytes
%SW137: the Serial Number - low bytes

Example: SN21143512345
%SW135: 21 - factory code
%SW136: 1435 - year(14) and week(35)
%SW137: 12345 - forder number (on 5 digit)

Released for: Schneider Electric India