Rockwell Automation 20D PowerFlex 700S with Phase I Control Reference Manual - Manual (Page 115)

Rockwell Automation Publication PFLEX-RM002D-EN-E - August 2013 115
Detail Drive Configuration and Operation Chapter 1
The feedback is also scaled so that base motor speed = 32768. The SLC/PLC-5
does not use DINT, and only handle 16 bit integers, so the feedback has to be
handled differently to account for references above 32767 or below -32768. The
following example shows how to read feedback values less than twice base motor
speed, but does not show the logic for the block transfer I/O messages. See
Chapter 4 of the 20-COMM-R User Manual for an example program for the
block transfer I/O messages.
Compute
Dest
F12:0
0.0
Expression (F12:1 I F12:4) * 32768.0
CPT
LES ADD
MOV
Less Than (ASource A
Source B
F12:0
0.0
-32768.0
-32768.0
Less Than (ASource A
Source B
Dest
F12:0
0.0
-65536.0
-65536.0
N10:10
0
Move
Source A
Dest
-1
-1
N10:10
0
EQU MOV
MOV
Equal
Source A
Source B
F12:0
0.0
-32768.0
-32768.0
Move
Source A
Dest
F12:0
0.0
N10:10
0
Move
Source A
Dest
-1
-1
N10:11
0
LIM MOV
MOV
Limit Test
Low Lim
Test
High Lim
-32767.0
-32767.0
F12:0
0.0
-1.0
-1.0
Move
Source
Dest
F12:0
0.0
N10:10
0
Move
Source A
Dest
-1
-1
N10:11
0
GRT SUB
MOV
Greater Than (A>B)
Source A
Source B
F12:0
0.0
32767.0
32767.0
Subtract
Source A
Source B
Dest
F12:0
0.0
65536.0
65536.0
N10:10
0
Move
Source A
Dest
-1
-1
N10:11
0
Convert the 32 bit floating point speed reference into 2, 16 bit intergers to
send over RIO.
F12:0 = 32 bit floating point speed reference (counts)
N10:10 = LSW of speed reference to send over RIO (counts)
N10:11 = MSW of speed reference to send over RIO (counts)
Calculate a speed reference based on 32768 = base motor speed.
F12:0 = 32 bit floating point speed reference (counts)
F12:1 = speed reference (RPM)
F12:4 = base motor speed (RPM)
0000
0001