To send break signals from a UNIX machine to serial devices using the TCP server mode, do the following:
- Establish a TCP connection with the TCP port 966 set as the command port.
The command/data used to send break signals to serial devices must go through the TCP command port (966) and not the data port (950). For example, in the 16-port NPort 5610, the command ports are TCP 966 (1st serial port) to 981(16th serial port).
- Use the following packet formats to control the break signal to the TCP command port of your serial device.
- To start a break command:
Send to the serial device: 2 bytes [0x21, 0x00]
Response from the serial device: 3 bytes [0x21, 'O', 'K']
- To stop the break command:
Send to the serial device: 2 bytes [0x22, 0x00]
Response from the serial device: 3 bytes [0x22, 'O', 'K']
- Use the UNIX function sleep() to control the duration of the break signal.