Some P77 (old released) might have some issues to be operated at certain Powerlink cycle time as (400us, 800us and 1600us) also ModuleOk will be FALSE.
this issue can be solved by doing FW update for the drive. However, the FW for the inverter (P77) is not part of the AS software packages, therefore, it needs to be done separately.
The solution on this case is to contact B&R support to help on the FW upgrade as it requires certain tools (Hardware & Software) and they will proceed with it.