Control Protocol Parts Explained - Mitsubishi Electric MELSEC FX Series User Manual

FX communication
7.4.3

Control Protocol Parts Explained

This is to explain the content of data set in each control procedure.
1 ) Control codes
The control codes are listed below.
Signal
STX
ETX
EOT
ENQ
ACK
a ) The programmable controller initializes the transmission sequence when receiving any
one of ENQ, ACK, NAK, and starts.
b ) When EOT, or CL code is received as follows, the programmable controller initializes the
transmission sequence. At this time, no response is made from the programmable
controller.
Code
Description
(Hexadecimal)
02H Start of Text
03H End of Text
04H End of Transmission
05H Enquiry
06H Acknowledge
Format 1
E
O
T
or
C
L
Computer
Programmable
controller
Signal
(Hexadecimal)
LF
CL
CR
NAK
Format 4
E C L
O
T R F
or
C C L
Computer
L R F
Programmable
controller
Computer link 7
Code
Description
0AH Line Feed
0CH Clear
0DH Carriage Return
15H Not Acknowledge
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