SJ700
2
Inverter
Appendix B
B–25
Explanation of
Function Codes
Read Coil Status [01h]:
This function reads the status (ON/OFF) of selected coils. An example follows below.
• Read intelligent input terminals [1] to [6] of an inverter having a slave address “8.”
• This example assumes the intelligent input terminals have terminal states listed below
(coils 13 and 14 are OFF).
• The data set in the response shows terminal states of coils 7 to 14.
• Data “17h = 00010111b” indicates the following assuming coil 7 is the LSB.
• When a read coil is outside the defined coils, the final coil data to be transmitted contains
“0“as the status of the coil outside the range.
• When the Read Coil Status command cannot be executed normally, see the exception
response.
Item
Data
Intelligent input terminal
[1]
[2]
[3]
[4]
[5]
[6]
Coil number
7
8
9
10
11
12
Terminal status
ON
ON
ON
OFF
ON
OFF
Item
Data
Coil number
14
13
12
11
10
9
8
7
Coil status
OFF
OFF
OFF
ON
OFF
ON
ON
ON
Query:
Note 1:
Broadcasting is disabled.
Note 2:
The starting coil number is one
less than the number of the coil to
be read first.
Note 3:
When 0 or more than 32 is
specified as a number of coils,
error code “03h” is returned.
Response:
Note 4:
Data is transferred by the specified
number of data bytes (data size).
No.
Field Name
Example
(hex)
1
Slave address *1
08
2
Function code
01
3
Coil start number
(high order)
00
4
Coil start number (low
order)
06
5
Number of coils (high
order) *2
00
6
Number of coils (low
order) *2
06
7
CRC-16 (high order)
5C
8
CRC-16 (low order)
90
No.
Field Name
Example
(hex)
1
Slave address
08
2
Function code
01
3
Data size (in bytes)
01
4
Coil data *4
17
5
CRC-16 (high order)
12
6
CRC-16 (low order)
1A
