Number Of Data Bytes - Mitsubishi Electric MELSEC IQ-R series Reference Manual

Control code used in a message (format 5) in binary code
The control code used for a message in binary code (format 5) is shown in the table below.
Symbol name Description
STX Start of Text
ETX End of Text
DLE Data Link Escape
■Additional code (10H)
The additional code is added to distinguish the data when the control code DLE (10H) is the same as the setting data in the
frame 5.
When '10H' is included in the data from "Number of data bytes" and "Request data" in the request message, the additional
code '10H' is added in front of the data.
When '10H' is included in the data from "Number of data bytes" and "Response data" in the response message, the additional
code '10H' is added.
('10H' is transmitted as '10H' + '10H'.)
Calculate the following value except for the additional code.
• Number of data bytes (setting item of format 5)
• Sum check code

Number of data bytes

A number of data bytes indicates the total number of bytes from the frame ID No. to control code.
Range
Calculate the data in the range from frame ID No. before DLE (10H) except for the additional code. (Page 35 Additional
code (10H))
Control code
Number of
DLE STX
data bytes
10 02
H H
Setting method
Set the data in binary code (format 5) at data communication.
Send 2-byte numerical value from the lower byte (L: bits 0 to 7).
Ex.
Response message (Normal completion: Response data)
• Frame ID No.: 1 byte
• Access route: 7 byte
• Response ID code, normal completion code: 4 bytes
• Response data: 2 bytes + additional code (10H) 1 byte
Number of data bytes = 1 + 7 + 4 + 2 = 14 (0EH)
Number of
Control code
data bytes
DLE STX
10 02 0E00
H H H
Code (hexadecimal)
02H
03H
10H
Frame
Control code
ID No.
DLE
F8
10
H H
Specify the number of
bytes in this range.
Frame Access route Response
ID No. ID code
F8 ( 7 bytes ) FFFF
H H
Specify the number of bytes in this range.
Sum check code
ETX
03
H
Normal Response
Control code
completion
data
code
DLE
0000 001010 10
H H
4 MESSAGES OF SERIAL COMMUNICATION MODULE
Sum check code
ETX
03
H H
4.3 Details of Setting Data
4
35