Hitachi ABB RVT Installation Und Betriebsanleitung Seite 552

The complete Modbus TCP/IP Application Data Unit is embedded into the data field of a standard TCP frame and sent
via TCP to well-known system port 502, which is specifically reserved for Modbus applications. Modbus TCP/IP cli-
ents and servers listen and receive Modbus data via port 502.
Modbus TCP must establish a connection before transferring data, since it is a connection-based protocol. The Mas-
ter (or Client in Modbus TCP) establishes a connection with the Slave (or Server). The Server waits for an incoming
connection from the Client. Once a connection is established, the Server then responds to the queries from the Client
until the client closes the connection.
The number of Clients connected to 1 specific RVT is limited to 5.
In summary:
– Modbus TCP allows the user to connect to a RVT12-3P through Ethernet or Internet using Modbus standard proto-
col (with HMI, SCADA...)
– The slave address of Modbus RTU specification is replaced by the IP address via TCP port 502.
– Multiple Clients may access multiple RVT Servers.
STATUS
Approved
SECURITY LEVEL
Public
DOCUMENT ID
9AKK106713A9758
RVT CO MM UNI CATI O N
REV. LANG. PAGE
K en 10/71
© 2022 Hitachi Energy. All rights reserved.