Serial port / serial interface. The most frequently used connector is CANON DB9 (Male / Female).
NETIO 4C provides a 3-wire serial port at its green terminal block.
Basic bi-directional serial communication uses 3 wires (RxD, TxD, GND). A full RS-232 serial port has 9 wires. The interface was originally intended for connecting a modem. Other connectors, such as CANON DB25 or RJ45, are sometimes used.
Maximum cable length is about 15 to 30 meters.
In the context of NETIO products
NETIO 4C provides a 3-wire serial port at its green terminal block.
The serial port can be redirected to a direct TCP socket transmission (to convert from a TCP connection at a specified TCP port to the serial port with a defined baudrate ¡V see the settings at the M2M API tab > Serial Console > Port)
Another option is to control the serial port directly with a Lua script acting as a M2M Active Client: Lua RS-232 (Serial port) ¡V see AN18 Lua access to RS-232 serial port