Specifications

STB NIP 2311 Services

EIO0000000051 6/2010 115

Modbus Messaging Service Description

The Modbus Messaging Services

The Modbus messaging service handles the transfer of data or commands between

two devices. One device is the client and the other is the server. The client initiates

the request and the server responds to the request. These services use the Modbus

protocol (or Modbus over TCP/IP in Ethernet applications) to support the data

transfer between devices.

1 SCADA and HMI data requests

2 PLC data transfer

3 device data gathering

Modbus Communication Standard

Modbus has been the industrial communication standard since 1979. It is now

combined with Ethernet TCP/IP to support Transparent Ready solutions.

Modbus over TCP/IP is an open Ethernet protocol. The development of a connection

to Modbus TCP/IP requires no proprietary component or license purchase. The

protocol may be easily combined with any device that supports a standard TCP/IP

communication stack. Specifications can be obtained free of charge from