Rockwell Automation 20-COMM-ER 20-COMM-ER Dual-Port EtherNet/IP Communication Adapter User Manual - Manual (Page 85)

Rockwell Automation Publication 20COMM-UM015B-EN-P - July 2013 85
Using the I/O Chapter 5
PowerFlex 7-Class Drives
The Reference value is an unscaled value; it is NOT in Hertz or RPM. The
Reference uses a ‘32767’ scale. The ‘32767’ endpoint of the scale is equal to the
value of drive parameter 55 - [Maximum Freq], which has a default value of 130
Hz. For all PowerFlex 70/700 drives, default scaling is 0…15123 which is equal to
0…60.0 Hz. This is based on the formula shown below. Reference scaling is
limited by drive parameter 82 - [Maximum Speed]. If the default value of 60 Hz.
for parameter 82 - [Maximum Speed] is changed, the speed Reference scaling also
changes. To determine Reference scaling, use the following formula:
(Parameter 82 ÷ Parameter 55) * 32767 = Scaling
Using drive parameter 82 and 55 default values, speed Reference scaling is:
(60 Hz ÷ 130 Hz) * 32767 = 15123
Therefore, 0…15123 = 0…60.0 Hz.
If parameter 82 - [Maximum Speed] is changed to 90 Hz, then:
(90 Hz ÷ 130 Hz) * 32767 = 22685
Therefore, 0…22685 = 0…90.0 Hz.
A graphic representation of this Reference scaling is shown below.
For PowerFlex 70 EC drives, firmware 2.xxx or later, or PowerFlex 700 VC drives,
firmware 3.xxx or later, drive parameter 298 - [DPI Ref Select] was added to
simplify scaling for the speed Reference. When drive parameter 298 - [DPI Ref
Select] is set to its default ‘0’ (Max Freq), the speed Reference scaling is as shown
above. However, when parameter 298 - [DPI Ref Select] is set to ‘1’ (Max Speed),
the speed Reference scaling is equal to parameter 82 - [Max Speed]:
Parameter 82 = Scaling
Using the parameter 82 default value, speed Reference scaling is:
0…32767 = 0…60.0 Hz.
If parameter 82 - [Maximum Speed] is changed to 90 Hz, then:
90 Hz = 32767
Speed Feedback uses the same scaling as the speed Reference.
0
0 Hz
P
ar
. 55 - [Maxim
um F
req]
Par. 82 - [Maxim
um Speed]
130 Hz
90 Hz
60 Hz
32767 22685 15123
Scaling = (Parameter 82 ÷ Parameter 55) * 32767