What does RTU mean in communications?
RTU communications is the way in which connected devices send and receive data to and from other supported devices over serial communication using the Modbus RTU protocol over physical serial lines like RS-232 or RS-485/422 in SCADA/industrial automation, allowing master devices (like PLCs or HMIs) to talk to slave devices (sensors, meters) by sending binary data packets with addresses, function codes, data, and CRC error checks, enabling remote monitoring and control.