Sinumerik Alarm 28005 NCU link: NCU %1 of the link network not running synchronously
%1 = NCU number
Error message of the NCU link module. When the NCU link was powered up, the local NCU (indicated by the alarm) detected that the NCU with the number in the alarm parameter was not running synchronously. This fault in the link can have various causes:
• The machine data which configure the NCU link are not identical on all NCUs.
• An identical interpolator cycle time has not been selected on all NCUs.
– Alarm display.
– Interface signals are set.
– NC not ready.
– Channel not ready.
– NC Start disable in this channel.
– NC Stop on alarm.
Check machine data configuration.
Switch control OFF – ON.
- Siemens Diagnostics Guide by Siemens