A01940 alarm in siemens 6RA80 DC Drive indicate that the clock cycle synchronism not reached. This means the bus is in the data exchange state and clock synchronous operation has been selected using the parameterizing telegram. It was not possible to synchronize to the clock cycle specified by the master.

1. Check the master application and bus configuration.
2. Check the consistency between the clock cycle input when configuring the slave and clock cycle setting at the master.
3. Check that no drive object has a pulse enable. Only enable the pulses after synchronizing the PROFIBUS/PROFINET drives.