I'm trying to run an ABB drive using S7-300 PLC through a profibus network. I used SFC14 and SFC15 to read and write from the drive. I'm recieving the trip, alarm and remote signals from the drive, and I'm sending the desired speed (Hz) which successfully appeared on the drive operating screen. I configured the drive to recieve the reference speed, the start stop sginals and the run enable signal from the PLC, however, I'm still receiving the non-ready signal from the drive and the drive does not respond to the run signal from the PLC.