Rockwell Automation 20D PowerFlex 700S with Phase I Control Reference Manual - Manual (Page 38)

38 Rockwell Automation Publication PFLEX-RM002D-EN-E - August 2013
Chapter 1 Detail Drive Configuration and Operation
To setup the PowerFlex 700S to follow a speed reference from the 20-COMM-D,
Parameter 691 [DPI Ref Select] must be set to “Port 5.” Parameter 16 [Speed Ref
Sel] must be set to “Speed Ref DPI.”
Reference and Feedback values are floating-point values in the PowerFlex 700S.
Use the following logic to transmit and receive reference and feedback data as
integer data.
In the ControlLogix system, Datalinks are transmitted over DeviceNet as 32 bit
integers (DINT). In order to send or receive floating point a COP (copy)
instruction must be used. The copy instruction in ControlLogix performs a
bitwise copy. Set the length of the copy instruction to a value appropriate for the
destination data type. For example, when copying a DINT data type to a REAL
data type, the length would be one (1) since both data types contain 32 bits of
data.
When using explicit messaging in the ControlLogix system, the message type
CIP Generic is used. The data is transferred over DeviceNet in the same data type
as the parameter in the PowerFlex 700S. Make sure that the data type for the
Source and Destination tags in your ControlLogix message instruction matches
the data type in the PowerFlex 700S. Also, the Number of Elements in the
ControlLogix message instruction must match the size of the Source data. For
example, to send an explicit message to write to parameter12 [Speed Ref 2],
which is floating point:
• The Source and Destination tags should be type REAL.
• The Number of Elements should be 4 bytes since a REAL data type takes
up 4 bytes of data.
Transmitted Reference
Floating Point Reference (RPM) 32768
×
Base Motor RPM
---------------------------------------------------------------------------------------------------- =
Floating point Feedback (RPM)
Feedback received Base Motor RPM
Ч
32768
---------------------------------------------------------------------------------------------- =