Omron M1 Series - Page 665

No. Field name Example (hex) Remarks
3
Register address (MSB)
*2
12
(Register address) = (Register number) − 1
4
Register address (LSB)
*2
16
5 Written data (MSB) 13 1388 hex → 5000 dec → 50.00 Hz
6 Written data (LSB) 88
7 CRC-16 (MSB) 60
8 CRC-16 (LSB) 20
*1. For a broadcast, no response will be sent back.
*2. Note that the holding register start address for C99(LOW) is 1216 hex, which is 1 less than the register
number 1217 hex: Register address = Register number - 1.

Response
No. Field name
Example
(hex)
1
Slave address
*1
01
2 Function code 06
3
Register address (MSB)
*2
12
4
Register address (LSB)
*2
16
5 Written data (MSB) 13
6 Written data (LSB) 88
7 CRC-16 (MSB) 60
8 CRC-16 (LSB) 20
*1. For a broadcast, no response will be sent back.
*2. Note that the holding register start address for C99(LOW) is 1216 hex, which is 1 less than the register
number 1217 hex: Register address = Register number - 1.
If the Write to Holding Register function is not executed normally, refer to 8-5-9 Exception Re-
sponse
on page
8-20.
8-5-5
Loop-back Test [08 hex]
Checks the communications between the master and the slave. Any value can be used for test data.
Example) Perform a Loop-back Test on Inverter with Slave Address
1

Query
No. Field name Example (hex)
1
Slave address
*1
01
2 Function code 08
3 Test sub code (MSB) 00
4 Test sub code (LSB) 00
5 Data (MSB) Any
6 Data (LSB) Any
7 CRC-16 (MSB) CRC
8 Communications Functions
8-15
M1 Series Standard Type User's Manual (I669)
8-5 Explanation of Each Function Code
8
8-5-5 Loop-back Test [08 hex]