Sinumerik Alarm 109005 No switchover: No displaceable MMC at the target PLC
MMC would like to go online to this NCU. At this NCU, two MMC’s are online on which uninterruptable processes are active (e.g.: data transfer between MMC and NCU).
Wait until at least one of the two MMC’s can be displaced and repeat the switchover.
- Siemens Diagnostics Guide by Siemens