Manual

82 Rockwell Automation Publication 750COM-UM003B-EN-P - November 2012
Chapter 6 Using Explicit Messaging
ControlLogix Controller Example Scattered Read Request Data
In this message example, we use the data structure in Figure 25 in the source tag
named Scattered Read Request to read these five 32-bit REAL (floating point)
parameters in a PowerFlex 750-Series drive:
• Parameter 001 - [Output Frequency]
• Parameter 007 - [Output Current]
• Parameter 008 - [Output Voltage]
• Parameter 009 - [Output Power]
• Parameter 011 - [DC Bus Volts]
See DPI Parameter Object
on page 115 (Class code 0x93) or Host DPI
Parameter Object on page 129 (Class code 0x9F) for parameter numbering.
Figure 25 - Example Scattered Read Request Data
ControlLogix Controller Example Scattered Read Response Data
The Scattered Read Request message reads the multiple parameters and returns
their values to the destination tag (Scattered_Read_Response). Figure 26
shows
the parameter values which, in this example, have been converted using a UDDT
for correct presentation. COP (Copy) instructions could have been used for this
purpose instead of a UDDT. If parameters being read are 32-bit integers, do not
COP the data to a REAL tag.
Figure 26 - Example Scattered Read Response Converted Data
In this message example, the parameters have the following values:
PowerFlex 750-Series Drive Parameter Read Value
1 - [Output Frequency] 60.205975 Hz
7 - [Output Current] 12.570678 Amp
8 - [Output Voltage] 418.34348V AC
9 - [Output Power] 12.3584 kW
11 - [DC Bus Volts] 566.5277V DC