Parameter value write, Plc block transfer emulation instruction data, Message operation – Rockwell Automation 1203-CN1 ControlNet Communications Module 1203-CN1 User Manual

Page 122: Example

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Publication 1203-5.13 – February, 2002

F-4

Supported Emulated Block Transfer Commands: Parameter Value Write

Parameter Value Write

Parameter Value Write writes a 16-bit parameter data value to the
selected parameter number.

PLC Block Transfer Emulation Instruction Data

PLC request instruction length: 4 word
Drive response instruction length: 4 words

Message Operation

Parameter Value Write sends a new value to the specified
parameter. The value must be in device units. Units for each
parameter are listed in the device manual.

If an error has occurred, word 1 of the response returns a value of
-31999, and word 3 contains a status code.

Example

In this example, a value of 4096 was sent to Parameter 20. 4096 is in
drive units and indicates a value of 100% Drive Rated Volts, as
defined in P147, Drive Rated Volts.

Data File Format

* Example only - These values vary depending on parameters and products.

Message Structure

Header Word 1

Data Word 2

PLC Request

Message Length

PLC Decimal Value

-31999 -- Message Error

Parameter Number

Drive Response

4

Data Word 3

Parameter Data

Header

Word 0

Header

Word 1

Data

Word 2

Message Length

PLC Decimal Value

769 -- Message OK

-31999 -- Message Error

Parameter Number

4

Data

Word 3

Status Word

Header Word 0

0

1

2

3

4

5

6

7

8

9

PLC request

4

-31999

20*

4096*

Drive response

3

769

20*

0

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