413
Station
No.
As
above
Example 1: Read the states of M10~M63 at the Salve #0 (total 54 bit devices)
Suppose the states of M10~M63 at the Salve #0 are as below: (composed to Byte values)
1
1
0
1
1
1
0
1
1
1
1
0
1
1
1
1
0
1
M63
0 0 0 0 0 0
0
1
1
0
1
1
1
0
1
1
1
1
0
1
1
1
1
0 0 0 0 0 0 0 0
0 0 0
0 0 00
M10(B0)
M26(B2)
M34(B3)
M58(B6)
55H
00H
ABH
2EH
D
L
E
10H
S
T
X
02H 21H00H
D
L
E
E
T
X
10H 03H07H 00H 92H 10H 00H 00H 36H 00H 30H
L H
〜
L H L H H L
30H
D
L
E
10H 00H
D
L
E
E
T
X
10H 03H
00H 08H 00H 55H 00H ABHAAH FFH 12H 46H 31H
L H B0 B1 B2 B3 B4 B6B5 H L
2EH
A
C
K
06H
※ 54 bits in total, 54 = 36H (the number of devices)
Function code 21H: to read bit devices (up to 1024 bits can be read at one command).
D
L
E
S
T
X
10H 02H
FFH
00H
〜
L H
〜
L H L H
D
L
E
E
T
X
10H 03H
H L
D
L
E
D
L
E
A
C
K
A
C
K
10H
10H
06H
06H
00H
XXH
L
H Bn
D
L
E
D
L
E
E
T
X
E
T
X
10H
10H
03H
03H
H
H
L
L
B0 B1
.....
01H 00H
21H XXH
8 bits
Fill the unused
devices as “0”
M18(B1)
M50(B5)
M42(B4)
AAH
FFH
12H
Command
to PLC
Feedback
from PLC
(error)
Feedback
from PLC
(complete)
Command
to PLC
Feedback
from PLC
(complete)
Number
of data
Bytes
Function
code
Station
No.
Device code
Head
number
of devices
Number
of
devices
SUM
Check
Data block
(Transmit unit: Byte)
SUM
Check
Error
code
Error
code
SUM
Check
Number
of data
Bytes
Station
No.
As
above
Station
No.
Station
No.
Number
of data
Bytes
Number
of data
Bytes
Function
code
Error
code
Device code
Number
of data
Bytes
Head
number
of devices
Number
of
devices
SUM
Check
SUM
Check
Status (by Byte values)
at M10~M63
To Next Page
Loading...
Need help?
General