Link read, Plc block transfer instruction data, Message operation – Rockwell Automation 1336T PLC Comm. Adapter, Series B, FRN 2.xx-3.xx User Manual

Page 175: Example, Link parameter read

Advertising
background image

7–29

Publication 1336 FORCE–5.13 –– September, 1998

The Link Parameter Read message reads the source parameter
number that is linked to the specified sink parameter.

PLC Block Transfer Instruction Data

BTW instruction length:

3 words

BTR instruction length:

4 words

Message Length

3

Header

Word 1

Header

Word 1

PLC Decimal Value

2304

Header

Word 2

Header

Word 3

Header

Word 2

Header

Word 3

PLC Decimal Value

2304 –– Message OK

Sink Parameter Link

-30464 –– Message Error

0

Parameter Number

Data

Word 4

Message Structure

Source Parameter

Number

PLC Request –– Block Transfer Write

Drive Response –– Block Transfer Read

Message Operation

The Link Parameter Read function specified in the BTW reads the
source parameter that is linked to the requested sink parameter,
defined in word 3 of the header message. The source parameter is
returned in word 4 of the BTR.

If an error has occurred, word 2 of the BTR returns a value of
-30464.

Example

In this example, the link associated with parameter 101 was
requested from the drive. The BTW header message word 4 defines
the sink parameter of the requested link with a value of 101. The
linked source parameter 330 is returned in word 4 of the BTR.

1

0

N10:0

2

3

4

5

6

7

8

9

N10:90

BTW
Data File

BTR
Data File

Data Format

101

0

101

330

3

0

2304

2304

Link Read

Link Parameter Read

Advertising