In Response Mode the application, special characters are output which are used to inform the application in the serial terminal device about the network-side connection status of the Com-Server This function is only available in TCP client mode. The following messages are output on the serial port: C (connected): The connection was opened successfully. There is a TCP connection to the server. N (not connected): The connection was not opened successfully. The TCP server is not responding. D (disconnected): The connection query was rejected by the TCP server or a previously open connection was properly ended by the TCP server or by the Com-Server. Ixxx.xxx.xxx.xxx (invoked by...): A client application on the indicated station has successfully opened a TCP connection to the Com-Server (e.g., I172.20.20.1).