Sinumerik Alarm 28001 NCU link connection to the NCU %1 of the link network has been aborted
%1 = NCU number
All NCUs in the NCU link network exchange data cyclically (sign-of-life). If this alarm occurs, sign-of-life signals have not been received from one other NCU on the NCU net- work. (see alarm parameters) This fault in the link can have various causes:
• Defective hardware.
• 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 the IPO cycle on all the NCUs.
• If necessary, check NCU link-specific alarms first.
Switch control OFF – ON.
- Siemens Diagnostics Guide by Siemens