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*

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