Message operation, Example, Parameter read full – Rockwell Automation 1336T ControlNet Frn1.02 Rev 1.5 User Manual
Page 58

4–16
Using Unscheduled Messaging
Publication 1336 FORCE–5.18 ––March, 1999
Data
Word 15
Parameter Text
Character 12
Character 11
Parameter Text
Character 14
Character 13
Parameter Text
Character 16
Character 15
File, Group, Element
Minimum Value
Maximum Value
Default Value
Unit Text
Character 2
Character 1
Unit Text
Character 4
Character 3
Data
Word 16
Data
Word 17
Data
Word 18
Data
Word 19
Data
Word 20
Data
Word 21
Data
Word 22
Data
Word 23
Drive Response –– PLC Message Read
Message Operation
The Parameter Read Full function specified in the PMW retrieves the
attributes of the requested parameter. The attributes for each
parameter include the data, minimum and maximum values, and the
parameter text. The response message returns this information,
beginning with data word 4. The parameter text is returned with each
data word containing two ASCII characters per word. This data
returns with the first and second characters in opposite order as
shown in the following example.
If an error has occurred in the block transfer, word 2 of the PMR
returns a value of -32000.
Example
In this example, a Parameter Read Full was performed through block
transfer on a 1336
FORCE. N7:10 shows the header message for the
PMW. The data is returned in the PMR data file, starting with word
4, for parameter 101. Word 4 shows the present value in drive units.
Words 5 through 9 provide scaling information, used to convert drive
units to engineering units. Words 10 through 17 provide the
parameter name.
Parameter Read Full
(continued)