Modbus – IAI America ROBO Cylinder Series User Manual

Page 82

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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.

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