Parameter value read – Rockwell Automation 1203 Serial Communications Module Series B User Manual

Page 59

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5–11

Block Transfer Emulation Instructions

1203–5.5 September 1995

The Parameter Value Read function 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

Data

Word 1

PLC Decimal Value

769

Message Structure

PLC Request

Header Word 1

Header Word 2

Header Word 3

Parameter Value or

Message Length

Drive Response

Parameter Number

3

(See Drive List)

Status Word

Message Operation

Parameter Value Read reads parameter values from the drive and
places that value (or an error code) in word 1 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 1 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 and a value of 4096 was returned. 4096 is the internal
drive unit value for the Maximum Rated Voltage Parameter. This
corresponds to a value of 100% Drive Rated Volts in Display Units.

Data File Format

0

N10:10

N10:90

1

2

3

4

5

6

7

8

9

3

769

20*

4096*

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

PLC request

Drive response

Parameter Value Read

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