Modbus – IAI America ROBO Cylinder Series User Manual

Page 285

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6. Modbus

ASCII

277

Modbus

(3) Query format

1 register = 2 bytes = 16-bit data

Field

Number of characters

(number of bytes)

ASCII mode

fixed character

string

Remarks

Header

1

‘:’

Slave address [H]

2

Arbitrary

Axis number + 1 (01

H

to 10

H

)

00

H

if broadcast is specified

Function code [H]

2

‘1’, ‘0’

Numerical value specification

Start address [H]

4

Arbitrary

Refer to 6.7.1. (2), “Start

address list”

Number of registers [H]

4

Arbitrary

Refer to 6.7.1 (2), “Start

address list”

Number of bytes [H]

2

In accordance with

the number of

registers above

Enter the value twice as large

as the number of registers

specified above

Changed data 1 [H]

4

Refer to 6.7.1 (2), “Start

address list”

Changed data 2 [H]

4

Refer to 6.7.1 (2), “Start

address list”

Changed data 3 [H]

4

Refer to 6.7.1 (2), “Start

address list”

:

:

Error check [H]

2

LRC calculation

result

Trailer

2

‘CR’, ‘LF’

Total number of bytes

Up to 256

(4) Response format

When normally changed, the response message responds with a copy of the query message

excluding the number of bytes and changed data.

Field

Number of characters

(number of bytes)

ASCII mode

fixed character

string

Remarks

Header

1

‘:’

Slave address [H]

2

Arbitrary

Axis number + 1 (01

H

to 10

H

)

00

H

if broadcast is specified

Function code [H]

2

‘1’, ‘0’

Numerical value specification

Start address [H]

4

Arbitrary

Refer to 6.7.1 (2), “Start

address list”

Number of registers [H]

4

Arbitrary

Refer to 6.7.1 (2), “Start

address list”

Error check [H]

2

LRC calculation

result

Trailer

2

‘CR’, ‘LF’

Total number of bytes

Up to 256

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