
MANUEL STA46
Modbus TCP
JP Viskovic 30/08/2005 OEE-F
6
1-4 Function
Code
1-4-0
I/O memory area (CIO) Read Multiple Coils
[Function]
Reads coils in I/O memory area.
[Request]
Length
Data
Function Code
1 Byte
0x01
Starting Address
2 Bytes
0x0000-0xFFFF
Quantity of Coils
2 Bytes
1-2000(0x7D0)
[Response]
Length
Data
Function Code
1 Byte
0x01
Byte Count
1 Byte
N
Coil Status
n Byte
n = N or N+1
Example: read 19 bits (CIO 0001.04 to 0002.06)
Request
Response
Data
Data
Function Code
0x01
Function Code
0x01
Starting Address(H)
0x00
Byte Count
0x03
Starting Address(L)
0x14
Coil Status 27-20
0xCD
Quantity of Coils(H)
0x00
Coil Status 35-28
0x6B
Quantity of Coils(L)
0x13
Coil Status 38-36
0x05
15 14 13
12 11
10
9 8 7 6 5 4 3 2 1 0
0CH
15 14 13
12 11
10
9 8 7 6 5 4 3 2 1 0
1CH 31
1
30
0
29
1
28
1
27
1
26
1
25
0
24
0
23
1
22
1
21
0
20
1
19 18 17 16
2CH
47 46 45 44 43 42 41 40 39 38
1
37
0
36
1
35
0
34
1
33
1
32
0
3CH
63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48
Italic characters
show the ON/OFF(1/0) status of its bit condition.