Link write, Plc block transfer instruction data, Message operation – Rockwell Automation 1336T ControlNet Frn1.02 Rev 1.5 User Manual
Page 81: Example, Link parameter write
4–39
Using Unscheduled Messaging
Publication 1336 FORCE–5.18 ––March, 1999
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
PLC instruction length:
4 words
PLC 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 –– PLC Message Write
Data
Word 4
Link Parameter
Drive Response –– PLC Message Read
Message Operation
The Link Parameter Write function specified in the PMW writes the
corresponding source parameter link to the defined linkable sink
parameter. The sink parameter is defined in word 3 of the PMW data
file with its linked source defined in word 4.
If an error has occurred in the link, word 2 of the PMR 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 PMR
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
N7:0
2
3
4
5
6
7
8
9
N7:0
PLC MSG
Write File
PLC MSG
Read File
Data Format
101
340
101
340
4
0
-30464
2304
Link Write
Link Parameter Write