Link read, Plc block transfer instruction data, Message operation – Rockwell Automation 1336T ControlNet Frn1.02 Rev 1.5 User Manual

Page 77: Continuous parameter link read

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4–35

Using Unscheduled Messaging

Publication 1336 FORCE–5.18 ––March, 1999

The Continuous Parameter Link Read message returns a list of up to
60 parameters that are linked to each drive parameter in a
consecutive list.

PLC Block Transfer Instruction Data

PLC Message Write instruction length:

4 words

PLC Message Read instruction length:

5-64 words

Message Length

4

Header

Word 1

Header

Word 1

PLC Decimal Value

4

Header

Word 2

Header

Word 2

PLC Decimal Value

4 –– Message OK

-327664 –– Message Error

0

Data

Word 5

Number of Parameter

Links to Read

Data

Word 3

Starting Parameter

Number

Data

Word 4

Number of Parameter

Links to Read

Data

Word 3

Starting Parameter

Number

Data

Word 4

Data

Word 6

Data

Word

Message Structure

Data

Word

Data

Word

Data

Word 64

Source Parameter

Number 1

Source Parameter

Number 2

Source Parameter

Number 60

PLC Request –– PLC Message Write

Drive Response –– PLC Message Read

Message Operation

The request must specify the number of links to be read and the
starting sink parameter number. The response returns the parameter
number of the source that is linked to each sink parameter. The
response returns links for a consecutive list of sink parameters (up to
60 links). If a parameter is not linked, a value of 0 is returned.

Link Read

Continuous Parameter Link Read

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