Instruction Manual

5. Modbus RTU
82
Modbus
(4) Query sample
A sample query that reads the current position (address 9003
H
) of a controller with axis No. 0 is
shown below.
z Query (silent intervals are inserted before and after the query)
01 03 90 03 00 01 59 0A
Field RTU mode
8-bit data
Start Silent interval
Slave address [H] 01
Function code [H] 03
Start address [H] 9003
Number of registers [H] 0001
Error check [H] 590A (in accordance with
CRC calculation)
End Silent interval
The response to the query is as follows.
z Response (silent intervals are inserted before and after the response)
01 03 02 90 00 D4 44
Field RTU mode
8-bit data
Start Silent interval
Slave address [H] 01
Function code [H] 03
Number of data bytes [H] 02 (2 bytes = 1 register)
Data 1 [H] 90 00
Error check [H]
D444 (in accordance with CRC calculation)
End Silent interval
The input data area address is “9000”
H
, o Convert into binary number
“1001000000000000.”
n n
INT15 -------------------- INT 1
Note The data of the response example is simply an example and will vary depending on
various conditions.