Cause : PB/PN sign-of-life synchronism not reached comes when the bus is in the data exchange state and clock synchronous operation has been selected using the parameterizing telegram.

Synchronization with the master sign-of-life (STW2.12 ... STW2.15) could not be completed because the sign-of-life is changing differently to how it was configured in the Tmapc time grid.

- ensure that the master correctly increments the sign-of-life in the master application clock cycle Tmapc.
- correct the interconnection of the master sign-of-life (p2045).