How to get the Modbus Plus communication protocol?

Modbus Plus is a proprietary protocol, you would have to buy a license to the protocol from Modicon. It's not an open standard like Modbus or Modbus TCP.

David Doggett

The unlike Modbus Serial and Modbus TCPIP the Modbus Plus protocol has not been openly published.

If you would like to implement Modbus plus on a computer please refer to the Modbus Plus interface cards from Schneider Electric - they are supplied with drivers etc. OR you may use software like the OPC server.

If you would like to implement it in some other device then please look at the web site "": for a partnering program that will allow you access to the chips and source code.

David Doggett
Some general information on Modbus-Plus protocol can be found in Modicon document 890 USE 102 00. Use the search tool at "": to find this. The specification for Modbus-Plus
is not at "": .

Modbus-Plus is a 1Mbs, peer-to-peer, token passing network that carries Modbus/RTU messages. The one byte slave address used in
Modbus/RTU is replaced by a five byte routing path.

Windows drivers for the Modbus-Plus adapters are available from Modicon. Windows OPC drivers are available from a number of sources. Drivers for QNX and Unix are available from 3rd parties. If you want to make your own host adapter I think you should talk to Modicon about buying the Modbus-Plus chip set, licensing, and a Modconnect parternship agreement.

Jay Kirsch
Thread starter Similar threads Forum Replies Date
G Modbus 1
A Modbus 1
A Modbus 0
F Modbus 4
B Modbus 1