Modbus – IAI America ROBO Cylinder Series User Manual

Page 178

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5. Modbus RTU

170

Modbus

5.6.2 Writing Position Table Data

(1) Function

Position table data can be changed using this query.

Every time an access is made to the start address list (address +0000

H

to +000E

H

), it is read out

of the non-volatile memory in the unit of 1 position data, and gets stored to the non-volatile

memory after the writing is executed.

* The EEPROM has a rewrite life of approx. 100, 000 times due to device limitations. If the

position table data is written frequently, the EEPROM will reach its rewrite life quickly and a

failure may occur. Accordingly, be careful not to let unexpected loops, etc., occur due to the

logics on the host side.

(2) Start address list

In a query input, each address is calculated using the formula below:

1000

H

+ (16 x Position number)

H

+ Address (Offset)

H

Example Change the speed command register for position No. 200

1000

H

+ (16 x 200 = 3200)

H

+ 4

H

= 1000

H

+ C80

H

+ 4

H

= 1C84

H

“1C84” becomes the input value for the start address field of this query.

* The maximum position number varies depending on the controller model and the PIO pattern

currently specified.

„

Position data change resisters

Address Symbol

Name

Sign

Register

size

Byte

size

Input

unit

+0000

PCMD

Target position

{

2

4

0.01 mm

+0002

INP

Positioning band

2

4

0.01 mm

+0004

VCMD

Speed command

2

4

0.01 mm/sec

+0006

ZNMP

Individual zone boundary +

{

2

4

0.01 mm

+0008

ZNLP

Individual zone boundary -

{

2

4

0.01 mm

+000A

ACMD

Acceleration command

1

2

0.01 G

+000B

DCMD

Deceleration command

1

2

0.01 G

+000C

PPOW

Push-current limiting value

1

2

%

+000D

LPOW

Load current threshold

1

2

%

+000E

CTLF

Control flag specification

1

2

* Addresses starting with “+” indicate offsets.

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