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

Page 180: Example, Link parameter write

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7–34

Publication 1336 FORCE–5.13 –– September, 1998

The Link Parameter Write message writes the source parameter link
to the linkable sink parameter. This function writes only one link.

PLC Block Transfer Instruction Data

BTW instruction length:

4 words

BTR instruction length:

4 words

Header

Word 1

Header

Word 1

PLC Decimal Value

-30464

Header

Word 2

Header

Word 3

Header

Word 2

Header

Word 3

PLC Decimal Value

2304 –– Message OK

Sink Parameter Number

-30464 –– Message Error

0

Sink Parameter Number

Message Structure

4

Data

Word 4

Link Parameter

PLC Request –– Block Transfer Write

Data

Word 4

Link Parameter

Drive Response –– Block Transfer Read

Message Operation

The Link Parameter Write function specified in the BTW writes the
corresponding source parameter link to the defined linkable sink
parameter. The sink parameter is defined in word 3 of the BTW data
file with its linked source defined in word 4.

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

Example

In this example, a link was defined between the sink parameter
defined in word 3 (parameter 101, External Velocity Reference), and
the source parameter (parameter 340, Analog Input 2). The BTR
header message confirmed the link by returning a value of 2034 in
word 2, and the link in order of sink-to-source in words 3 and 4.

1

0

N10:0

2

3

4

5

6

7

8

9

N10:90

BTW
Data File

BTR
Data File

Data Format

101

340

101

340

4

0

-30464

2304

Link Write

Link Parameter Write

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