Rockwell Automation 25-COMM-D PowerFlex 525 DeviceNet Adapter - Manual (Page 49)

Rockwell Automation Publication 520COM-UM002A-EN-E - April 2013 49
Using the I/O Chapter 5
When using a CompactLogix/ControlLogix controller, the 16-bit INT
Reference word is always INT 1 in the output image (see
CompactLogix
Controller I/O Image for PowerFlex 520-Series Drives on page 48 ) and the
16-bit INT Feedback is always INT 1 in the input image.
The Reference and Feedback 16-bit INT values represent drive speed. The
scaling for the speed Reference and Feedback is 0.01 Hz. For example, a 16-bit
INT Reference value of ‘3000’ would equal a Reference of 30.00 Hz. Note that
the commanded maximum speed can never exceed the value of
Host parameter
P044 [Maximum Freq] . PowerFlex 520-Series Drive Example Speed Reference/
Feedback Scaling on page 49 shows example References and their results for a
PowerFlex 520-series drive that has its:
•
Host parameter P043 [Minimum Freq] set to 10.00 Hz.
•
Host parameter P044 [Maximum Freq] set to 50.00 Hz.
Using Datalinks A Datalink is a mechanism used by PowerFlex drives to transfer data to and from
the controller. Datalinks allow a drive parameter value to be read or written to
without using an Explicit Message. When enabled, each Datalink occupies one
16-bit word in a ControlLogix, CompactLogix, or MicroLogix controller.
The following rules apply when using PowerFlex 525 drive Datalinks:
• Datalinks can not be used with Multi-drive mode.
• The target of a Datalink can be any appropriate
Host parameter. For
example,
Host parameter P041 [Accel Time 1] can be the target of the
DeviceNet adapter installed in the drive.
• The data passed through the drive’s Datalink mechanism is determined by
the settings of the following parameters
–
Device parameter 02 [DLs From Net Cfg]
–
Device parameter 04 [DLs To Net Cfg]
–
Host parameters C161...C164 [Opt Data In 1...4]
PowerFlex 520-Series Drive Example Speed Reference/Feedback Scaling
Network Reference Value Speed Commanded Value Output Speed Network Feedback Value
10000 100.00 Hz 50.00 Hz (1)
(1) The drive runs at 50.00 Hz instead of 100.00 Hz or 65.00 Hz because Host parameter P044 [Maximum Freq] sets 50.00 Hz as the
maximum speed.
5000
6500 65.00 Hz 50.00 Hz
(1)
5000
3250 32.50 Hz 32.50 Hz 3250
0 0.00 Hz 0.00 Hz 0
IMPORTANT Attempting to write a negative value to the Speed Reference will result in the
drive ramping to maximum speed due to overflow, the direction of the drive
can only be controlled programmatically with the appropriate bits (bits 4 and
5) in the Command Word.