Chapter 5 Messages Of Ethernet Interface Module; Types And Purposes Of Messages; Code - Mitsubishi Electric MELSEC IQ-R series Reference Manual

5
MESSAGES OF ETHERNET INTERFACE
MODULE
This section explains the specifications of the messages and access range of MC protocol when connecting with Ethernet
communication from an external device.
5.1

Types and Purposes of Messages

The messages of MC protocol can be classified as shown in the following table depending on the supported device and its
intended purpose.

Code

ASCII code and binary code are available.
Set the operation settings with Engineering tool.
Communication using binary code shorten the communication time since the amount of communication data
is reduced by approximately half as compared to the one using ASCII code.
Data storage order
The data size and the storing order of values for data in each item vary between ASCII code and binary code.
■Data communication in ASCII code
Data is stored in order from the upper byte to the lower byte.
■Data communication in binary code
Data is stored in order from the lower byte to the upper byte.
Ex.
Subheader of 4E frame request message (serial No. is '1234')
ASCII code
Serial number
5 4 0 0 1 2 3
35 34 30 30 31 32 33
H H H H H H
(Fixed value)
4 0 0 0 0
34 30 30 30 30
H H H H H H
(Fixed value)
Binary code
Serial number
54 00 34 12 00 00
H H H H H H
(Fixed value)
(Fixed value)
5 MESSAGES OF ETHERNET INTERFACE MODULE
5.1 Types and Purposes of Messages
5
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