
EM58 – HS58 - HM58 MODBUS TCP/IP
•
it supports standard Ethernet and does not require dedicated Masters or
chipsets; standard PC Ethernet cards and PCs can be used to
communicate in any Ethernet network;
•
it does not require any configuration file;
•
it does not need any specific software thanks to the possibility of
integrating a web server: it is designed to offer helpful functions and
deliver complete information on the device that can be accessed
through the Internet.
In particular it allows:
◦
to display and check the currently set parameters;
◦
to set the network communication parameters;
◦
to set the device work parameters;
◦
to upgrade the firmware;
◦
to monitor the device and access some advanced maintenance
functions.
The web server can be accessed from any PC running a web browser.
6.2 General MODBUS frame description
The MODBUS application protocol defines a simple
Protocol Data Unit (PDU)
independent of the underlying communication layers:
Function Code
Data
MODBUS PDU
The mapping of MODBUS protocol on a specific bus or network introduces some
additional fields on the
Application Data Unit (ADU)
. The Client that initiates a
MODBUS transaction builds the MODBUS Application Data Unit, and then adds
fields in order to build the appropriate communication ADU. The function code
indicates to the Server which kind of action to perform.
MODBUS RTU ADU
Address
Function Code
Data
Checksum
MODBUS PDU
6.3 MODBUS on TCP/IP Application Data Unit
MODBUS TCP/IP uses TCP/IP and Ethernet to carry the data of the MODBUS
message structure between compatible devices. That is, MODBUS TCP/IP
combines a physical network (Ethernet) with a networking standard (TCP/IP),
and a standard method of representing data (MODBUS as the application
MAN EM58_HS58_HM58 MT E 1.1.odt
MODBUS® TCP/IP interface 35 of 104
Summary of Contents for EMC58 MT
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