Instruction Manual

5. Modbus RTU
71
Modbus
(4) Query sample
A sample query that reads the total moving distance (addresses 8402
H
to 8403
H
) of a controller
with axis No. 0 is shown below.
z Query (silent intervals are inserted before and after the query)
01 03 84 02 00 02 4D 3B
Field RTU mode
8-bit data
Start Silent interval
Slave address [H] 01
Function code [H] 03
Start address [H] 8402
Number of registers [H] 0002
Error check [H] 4D3B (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 04 00 00 40 9E 4A 5B
Field RTU mode
8-bit data
Start Silent interval
Slave address [H] 01
Function code [H] 03
Number of data bytes [H] 04 (4 bytes = 2 registers)
Data 1 [H] 00 00
Data 2 [H] 40 9E
Error check [H]
4A5B (in accordance with CRC calculation)
End Silent interval
The Total moving distance is “0000409E
H
” o Convert into decimal number o 16542 m
Note The data of the response example is simply an example and will vary depending on
various conditions.