Rockwell Automation 1395 Node Adapter Board - Manual (Page 17)

Chapter 3
Functional Description
3-5
If the data transferred between the drive and PLC Controller will be
manipulated (in the PLC Controller) in units other than drive units, the
PLC Controller program must scale the information. The scaled
information must be based on the drive units definitions for the parameters
in the drive. The External Vel Ref (Parameter 154) is in drive units where
4096 is defined as base speed. If the PLC Controller program is written in
terms of feet per minute (FPM), then FPM must be converted to drive units
before being sent to the drive.
Figure 3.3 provides an example PLC Controller program which could be
used to control the drive. Based on the configuration shown in Figure 3.2,
the PLC Controller program will be transferring information to Parameter
150 and 154 in the drive. Integer file N7 in the PLC is being used for drive
logic control and integer file N10 word 01 is used to store the drive speed
reference. To control the logic operation of the drive, the PLC program
must control the bits in the output image table which correspond to the
desired operation. Because Parameter 300 has been linked to Parameter
150 (Figure 3.2), and Parameter 300 is associated with group 1 in the
output image table, the PLC Controller program will be controlling bits in
word 0:21.