What is Modbus RTU?

Modbus RTU is a serial communication protocol that uses RS485 technology. In simple terms, it is a method used for transmitting information over serial lines (RS485) between electronic devices. The device requesting the information is called the Master and the devices supplying information are slave devices. On a standard Modbus RTU network, there is one Master and up to 247 Slaves, each with a unique Slave Address from 1 to 247. The Master can also write information to the Slaves.