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Chapter 7 Communication function
7-45
4)
Example of use
In case 1 WORD from %MW20 of station No.1 and 1 WORD from %QW0.2.1 address are read supposing that
data of H1234 is in %MW20 and data of H5678 is in %QW0.2.1.
(Computer request format)
Format
Name
Header
Station
No.
Command
Command
type
Number of
blocks
Variable
Length
Variable name
Variable
length
Variable name Tail
Frame
check
Frame(Ex) ENQ H01
R(r)
SS
H02
H05
%MW20
H08 %QW0.2.1 EOT
BCC
ACSII value
H05
H3031
H52(72)
H5353
H3032
H3035
H254D573230
H3038
H255157302E
322E31
H04
(For PLC ACK response after execution of command)
Format
Name
Header
Station
No.
Command
Command
type
Number of
blocks
Variable
length
Variable name
Variable
length
Variable name Tail
Frame
check
Frame(Ex.)
ACK
H01 R(r) SS H02 H02 H1234 H02 H5678
ETX
BCC
ACSII value
H06
H3031
H52(72)
H5353
H3032
H3032
H31323334
H3032 H35363738 H03
(For PLC NAK response after execution of command)
Format
Name
Header
Station
No.
Command
Command
type
Error code
Tail
Frame
check
Frame(Ex.) NAK H01
R(r)
SS
Error
code(2)
ETX
BCC
ACSII value
H15
H3031
H52(72)
H5353
Error code(4)
H03