11. Connection to other devices
11.4 Modbus TCP
11.4.2 Programming communication with Modbus TCP
In order to program these communications, you will need at least one system that ful-
fills the functionality of a Modbus TCP client and that is able to send commands to the
lower-level server.
Since the easyE4 control relays can work with various Modbus TCP clients available on
the market, only standard-compliant Modbus TCP functions are supported.
In other words, functions that are defined in a standardized manner in the Modbus
standard and are accordingly implemented at the protocol level in a standardized man-
ner by all Modbus TCP stations. For more information, please refer to the MODBUS
MESSAGING ON TCP/IP IMPLEMENTATION GUIDE V1.0b published by the Modbus
Organization.
Connection:
In order for the Modbus TCP server to work, the following ports must be opened:
l
Modbus TCP: Service—Port 502
Port 502 is normally set by default. If it is not, make sure to set it when establishing a
connection.
Ports that may need to be opened depending on the functionality being used:
l
DNS: UDP/TCP port 53 (only if using DNS)
l
DHCP: UDP port 67 for server / UDP Port 68 for clients (only if using DHCP)
The Modbus TCP server implementation on the easyE4 will provide the following stand-
ard functions:
Function description
Function
Code
Read Coils
Used to read outputs
0x01
Read Discrete Inputs
Used to read inputs
0x02
Read Holding Registers
Used to read output registers
0x03
Read Input Registers
Used to read input registers
0x04
Write Single Registers
Used to write to a register
0x06
Write Multiple Registers
Used to write to multiple registers
0x10
There are two basic protocol data units (PDUs) for each of the function descriptions
above:
1. Request PDU (the Modbus TCP server must receive this PDU)
a. Byte 0 contains the function code, which is used to identify the function that
is desired
b. The remaining bytes are function-specific
2. Response PDU (the Modbus TCP server must send this PDU)
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easyE4
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Summary of Contents for easyE4 series
Page 1: ...Manual 11 18 MN050009 EN easyE4 Manual...
Page 4: ......
Page 16: ...12 easyE4 11 18 MN050009 EN www eaton com...
Page 22: ...0 1 About this manual 18 easyE4 11 18 MN050009 EN www eaton com...
Page 169: ...easyE4 11 18 MN050009 EN www eaton com 165...
Page 490: ...7 System settings 7 16 Time and Date setting 486 easyE4 11 18 MN050009 EN www eaton com...
Page 520: ...9 easyE4 inside 9 7 NET network 516 easyE4 11 18 MN050009 EN www eaton com...
Page 570: ...11 Connection to other devices 11 6 E mail function 566 easyE4 11 18 MN050009 EN www eaton com...
Page 578: ...12 Faults 12 4 Functionality of the NET faulty 574 easyE4 11 18 MN050009 EN www eaton com...
Page 582: ...13 Maintenance 13 3 Storage transport and disposal 578 easyE4 11 18 MN050009 EN www eaton com...
Page 594: ...590 easyE4 11 18 MN050009 EN www eaton com...