Ok I assume you are wanting to connect in a similar manner to the diagram in the IP-A manual?
If yes then the Emergency Stop signal to your drive would be used. It requires a connection to 0v on your drives, ie break the connection and the drive E-Stops. To do that you would have SG (CN1B 10) one side of the relay contact on the PNOZ and the other side of the relay would be to EMG (CN1B 15)
See pic below.
Hood