Chapter 4 Explanation of Functions
 
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(v) Performing a loopback test [08h]
 
The loopback test function is used to check the communication between the external control system 
(master) and the inverter (slave). 
 
(Example) 
When performing a loopback test with the inverter at slave address "1":
 
 
 
 
 
 
 
 
 
 
 
 
 
 
The diagnosis subcode only conforms to the echoing of query data (00h, 00h). It cannot be used for other 
commands. 
 
(vi) Writing data to multiple coils [0Fh]
 
This function rewrites data in sequential coils. 
 
(Example) 
When updating the status of the intelligent input terminals [1] to [6] of the inverter at slave address "5":
 
The status of the intelligent input terminals is updated to the status shown in the following table: 
 
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 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
If the function to write data to multiple coils cannot be executed normally, the inverter will return an 
exception response. For details, see Item (viii), "Exception response." 
Query 
  Field name  Sample setting 
(hexadecimal) 
1  Slave address (*1)  01
2 Function code  08
3  Diagnosis subcode (upper digit)  00
4  Diagnosis subcode (lo
er digit)  00
5  Data (upper digit)  Arbitrary
6  Data (lower digit)  Arbitrary
7  CRC-16 code (upper digit)  CRC
8  CRC-16 code (lower digit)  CRC
*1   This query cannot be broadcasted. 
Response 
Field name Sample setting 
(hexadecimal) 
1 Slave address 01
2 Function code 08
3 Diagnosis subcode (upper digit)  00
4 Diagnosis subcode (lo
er digit)  00
5 Data (upper digit) Arbitrary
6 Data (lower digit) Arbitrary
7 CRC-16 code (upper digit)  CRC
8 CRC-16 code (lower digit)  CRC
 
Query 
  Field name  Sample setting 
(hexadecimal) 
1  Slave address (*1)  05
2 Function code  0F
3  Starting coil numbe
(upper digit) (*2) 
00
4  Starting coil numbe
(lower digit) (*2) 
06
5  Number of coils (upper digit)  00
6  Number of coils (lower digit)  06
7  Number of data bytes (*3)  02
8  Updating data (upper digit) (*3)  17
9  Updating data (lo
er digit) (*3)  00
10  CRC-16 code (upper digit)  DB
11  CRC-16 code (lower digit)  3E
*1  If this query is broadcasted, no inverter will return any 
response. 
*2  Note that the starting coil number is 1 less than the 
actual coil number of the coil to which the data is to be 
written first. 
*3 The updating data consists of the upper and lower digits. 
Even when updating an odd number of data bytes, add 
1 to the number of data bytes to make it an even 
number before specifying the number of data bytes. 
Response 
Field name Sample 
setting 
(hexadecimal)
1 Slave address 05
2 Function code 0F
3 Starting coil numbe
 digit)  00
4 Starting coil numbe
(lower digit)  06
5 Number of coils (upper digit)  00
6 Number of coils (lower digit)  06
7 CRC-16 code (upper digit)  34
8 CRC-16 code (lower digit)  4C