Rockwell Automation 1203-CN1 ControlNet Communications Module 1203-CN1 - Manual (Page 121)

Publication 1203-5.13 – February, 2002
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: 4 word
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 the Maximum Rated Voltage Parameter. 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
Message Structure
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
Header 1.OR.0x8000
Header 2
Header
Word 2
Header
Word 1
Header
Word 0
0 1 2 3 4 5 6 7 8 9
PLC request 3 769 20*
Drive response 6 769 20* 4069