Omron MX2 Series - Read;Write From;To Multiple Holding Registers [17 H]

8 Communications Functions
8 - 19
Multi-function Compact Inverter 3G3MX2-EV2 User’s Manual (I666-E1)
8-5-8 Read/Write from/to Multiple Holding Registers [17h]
Reads data from and writes data to consecutive multiple holding registers in a continuous manner.
Because the holding registers 0001 to 0002 hex for the Output Frequency Setting/Monitor (F001) have
a data resolution of 0.01 s, to set 50.00 Hz, set the written data to 5000 (0000 1388 hex).
Similarly, the holding registers for the Output Frequency Monitor (d001) are 1001 to 1002 hex.
⚫ Query
(Register address) = (Register number) − 1
(Register address) = (Register number) − 1
0000 1388 hex → 5000 dec → 50.00 Hz
⚫ Response
0000 1388 hex → 5000 dec → 50.00 Hz
*1. Broadcasting cannot be performed.
*2. Note that the holding register start address is 1 less than the register number: Register address = Register
number - 1.
If the Read/Write from/to Multiple Holding Registers function is not executed normally, refer to 8-5-9
Exception Response on page 8-20.
8
8-5 Explanation of Each Function Code
8-5-8 Read/Write from/to Multiple Holding Reg- isters [17h]
No.
Field name
Example
[hex]
1
Slave address
*1
01
2
Function code
17
3
Read register start address (MSB)
*2
10
4
Read register start address (LSB)
*2
00
5
Number of read registers (MSB)
00
6
Number of read registers (LSB)
02
7
Write register start address (MSB)
*2
00
8
Write register start address (LSB)
*2
00
9
Number of write registers (MSB)
00
10
Number of write registers (LSB)
02
11
Number of written data bytes n
04
12
Written data 1 (MSB)
00
13
Written data 1 (LSB)
00
14
Written data 2 (MSB)
13
15
Written data 2 (LSB)
88
16
CRC-16 (MSB)
F4
17
CRC-16 (LSB)
86
No.
Field name
Example
[hex]
1
Slave address
*1
01
2
Function code
17
3
Number of read data bytes n
04
4
Read data 1 (MSB)
00
5
Read data 1 (LSB)
00
6
Read data 2 (MSB)
13
7
Read data 2 (LSB)
88
8
CRC-16 (MSB)
F4
9
CRC-16 (LSB)
71
Example. Writing 50.00 Hz to Output Frequency Setting/Monitor
(F001) and Reading from Output Frequency Monitor (d001) Value
from Inverter with Slave Address 1