What is Modbus RTU?
Modbus is a communication protocol developed in the late 1970s for the PLCs. Over the years, it has become one of the most widely used standards in the world of industrial devices. It is difficult to find a device (PLC, HMI, Drive) that does not have Modbus protocol support. In communications on serial interfaces (RS232 and RS485) the RTU version is the most used one, compared to the ASCII version (less compact and efficient). In 2004, the Modbus Organization (www.modbus.org) has been established and it’s composed of producers and users responsible for the development and the promotion of the protocol.
In recent years serial communication (RS232 and RS485) has been replaced by the modern and fast Ethernet technology and also the Modbus protocol has evolved in the Modbus TCP/IP version, maintaining all the features and functionalities of the RTU version but benefiting from a much faster physical support.
So, the device parameters access mode (Coil, Holding Registers, etc.) has been maintained and the upgrade to modern technology was more “painless” than having to implement a completely different protocol in logic.
Which are the advantages of Modbus RTU?
1) Modbus it’s a protocol created for the use in the industrial field
2) The Modbus Organization does not require royalties for the use of Modbus technology and makes available all the necessary documentation for its implementation
3) Modbus protocol is very simple to implement even on devices with limited computing capacity or limited memory
4) Modbus protocol is very fast and efficient, especially on serial interfaces
5) There are both commercial and free libraries for quick implementation in your own solutions
6) The majority of industrial devices support Modbus
Ever Elettronica drives for stepper motors and brushless motors with Modbus RTU
Ever Elettronica introduced support for the Modbus RTU protocol on its products in the late 1990s.
All our devices equipped with a serial interface (RS232 or RS485) implement and support the Modbus RTU protocol, while all the new generation devices that have an Ethernet interface support Modbus TCP/IP.
Among the various types of objects that Modbus defines, Holding Registers are supported to access all the operating parameters of the device.
The supported Modbus functions are: 3 (Read multiple Holding Registers), 6 (Write single Holding Register), 16 (Write multiple Holding Registers), 23 (Read / Write multiple Holding Registers).
Ever Elettronica stepper and brushless drivers with Modbus RTU or Modbus TCP/IP fieldbuses are programmable through E3PLC: thanks to this, it is possible to write and download a complete program into the driver in order to distribute the machine intelligence and handle all the real-time processes on the driver’s microprocessor.
Find out more about our range of Modbus RTU drives for stepper motors and brushless motors