Modbus – IAI America ROBO Cylinder Series User Manual

Page 158

Advertising
background image

5. Modbus RTU

150

Modbus

(5) Query sample

Examples of different operations are shown in [1] to [3] below.

[1] A sample query that turns the servo of a controller of axis No. 0 on and then executes home

return operation is performed.

Query (silent intervals are inserted before and after the query)

First time

01 06 0D 00 10 00 86 A6 --- Servo ON

Second time 01 06 0D 00 10 10 87 6A --- Home return

Field

RTU mode

8-bit data

Start

Silent interval

Slave address [H]

01

Function code [H]

06

Start address [H]

0D00

Changed data [H]

First time: 1000

Second time: 1010

(Keep the servo ON bit 1 in cases

other than when the servo is OFF.)

Error check [H]

First time: 86A6

(in accordance with CRC calculation)

Second time: 876A

(in accordance with CRC calculation)

End

Silent interval

Note 1 Home return is not performed even if 1010

H

is sent to change the data while the

servo is OFF (refer to the timing chart at startup of each RC controller).

Note 2 To keep the previous status, send the previous status even if there is no change.

As in the example above, keep the servo ON bit as 1 at home return as well.

If the change is successful, the response message will be the same as the query.

[2] Move to position No. 1 using the position movement specification register (address 9800

H

).

Before this operation, perform the operation in example [1] above to complete a home return.

Query (Silent intervals are inserted before and after the query.)

01 06 98 00 00 01 67 6A

Field

RTU mode

8-bit data

Start

Silent interval

Slave address [H]

01

Function code [H]

06

Start address [H]

9800

Changed data [H]

0001

Error check [H]

676A (in accordance with CRC

calculation)

End

Silent interval

Advertising