Instruction Manual

5. Modbus RTU
74
Modbus
(5) Query sample
A sample query that reads the present time of PCON-CA (addresses 8420
H
to 8421
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 20 00 02 ED 31
Field RTU mode
8-bit data
Start Silent interval
Slave address [H] 01
Function code [H] 03
Start address [H] 8420
Number of registers [H] 0002
Error check [H] ED31 (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 17 2C 1B 8B 74 D9
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] 17 2C 1B 8B
Error check [H]
74D9 (in accordance with CRC calculation)
End Silent interval
Current time is 14h:43m:23s April 26, 2012.
Note The data of the response example is simply an example and will vary depending on
various conditions.