Rockwell Automation 1336T ControlNet Frn1.02 Rev 1.5 - Manual (Page 56)

4–14 Using Unscheduled Messaging
Publication 1336 FORCE–5.18 ––March, 1999
Message Operation
The Scattered Parameter Value Read function specified in the PMW
reads a pre-defined group of parameter values, in any order, from the
device. Word 3 of the PMW data file defines the number of
parameters to be read. The parameters to be read and their order is
defined starting with word 4. An unused word is left between each
parameter request, so the PMR can respond with the parameter value
as shown.
If an error has occurred in reading any of the parameters:
•
Word 2 of the PMR returns a value of -32765.
•
Bit 15 of the PMR word for the number of that parameter is set.
•
The PMR word for the value of that parameter returns a status
word instead of the parameter value.
Example
In this example, eight parameters were read from a 1336 FORCE, as
defined in word 3 of the PMW data file. The requested parameter
numbers were 5, 7, 8, 20, 18, 17, 19, and 36. The PMR response
returned the values of these parameters into the PMR data file. These
values are in drive units.
1 0
N7:10
2 3 4 5 6 7 8 9
N7:20
PLC MSG
Write File
PLC MSG
Read File
Data Format
8 5
0 17
19
0
3
18
0
0
7
19
0
0
8
36
0
0
20
N7:90
N7:100
8 5
4096 17
0
4096
3
18
6
51
7
19
1000
60
8
36
1000
6144
20
➀ ➀ ➀ ➀ ➀
➀ ➀ ➀ ➀ ➀
➀ ➀ ➀ ➀ ➀ ➀ ➀ ➀
➀ ➀ ➀ ➀ ➀ ➀ ➀ ➀ ➀
➀ These values vary depending on parameters and products.
Scattered Parameter Value Read
(continued)