Parameter value read, Plc block transfer emulation instruction data, Message operation – Rockwell Automation 1203-GK5 DeviceNet Communications Module FRN 1.xxx-3.xxx User Manual
Page 123: Example
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Supported Emulated Block Transfer Commands (Parameter Value Read)
F-3
Parameter Value Read
Parameter Value Read reads the 16-bit parameter data value for the
selected parameter number.
PLC Block Transfer Emulation Instruction Data
PLC request instruction length: 3 words
Drive response instruction length: 1 word
Figure F.2
Message Structure
Message Operation
Parameter Value Read reads parameter values from the drive and
places that value (or an error code) in word 3 of the drive response
data file. The value is shown in device units. Device units are listed in
the user manual for the device you are using.
If an error occurs:
•
Word 3 of the response contains the status code.
•
The status area of the data file is non-zero.
Example
In this example, the value of parameter 20 was requested from a 1336
PLUS drive and a value of 4096 was returned. 4096 is the internal
drive unit value for Maximum Rated Voltage. This corresponds to a
value of 100% Drive Rated Volts in Display Units.
Data File Format
* Example only — These values vary depending on parameters and products.
Data
Word 3
PLC Decimal Value
769
PLC Request
Header Word 0
Header Word 1
Header Word 2
Parameter Value or
Message Length
Drive Response
Parameter Number
3
(See Drive List)
Status Word
Header 0
PLC Decimal Value
Header 2
Header
Word 2
Header
Word 1
Header
Word 0
769=OK –31999=Error
0
1
2
3
4
5
6
7
8
9
PLC request
3
769
20*
Drive response
6
769
20*
4069*