Section 7 Modbus Tcp Communication; Modbus Tcp/Ip; Connection To Client; Protocol Server Attachment To A Client - ABB Remote I/O RIO600 Installation And Commissioning Manual

1MRS757488 H
Section 7
7.1
7.1.1
7.1.2
7.1.3
RIO600
Installation and Commissioning Manual
Modbus TCP communication

Modbus TCP/IP

Modbus is a communication protocol developed by Modicon Company in 1970s. It
was used originally for communication in PLCs and RTU devices but later the
Modbus protocol has been used in a variety of different device applications.
The Ethernet based Modbus TCP/IP communication in this IED follows the
specifications maintained by Modbus Organization. The Modbus communication
reference guides can be downloaded from Technical Resources on www.modbus.org.
RIO600 is designed to operate with a wide range of different Modbus masters and
clients. The word "client" refers to the protocol master. RIO600 is referred to as
"server" or a slave device. RIO600 can communicate with one Modbus protocol client
at a time.
Modbus TCP can be used in parallel with IEC 61850 GOOSE.

Connection to client

In RIO600, it is possible to activate one Modbus protocol server instance. Modbus
TCP server is activated by setting the Modbus operation parameter to "ON" and
selecting Write to IED in PCM600. Modbus TCP can be used in parallel with the IEC
61850 GOOSE.

Protocol server attachment to a client

After protocol activation, RIO600 should be connected to the intended client. When
the client makes a TCP connection, its IP address is checked. Protocol reservation is
given to the client with this IP address. Modbus TCP client must use the Slave ID in
its data requests to ensure responses from RIO600. The Slave ID is set through
Parameter Setting in PCM600.

TCP/IP link

RIO600 operates as a ModbusTCP/IP server. A Modbus TCP/IP client can establish
a connection to RIO600 through the standardized TCP socket port 502. The Modbus
TCP/IP interface of RIO600 can be configured to accept one Modbus client IP
address. The analog output and binary output write authority for the Modbus TCP/IP
client is configurable, for example, if Modbus TCP is used only for monitoring and
RIO600 outputs are operated using IEC 61850 GOOSE.
Modbus TCP communication
Section 7
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