Rockwell Automation 20G PowerFlex 750-Series AC Drives - Manual (Page 107)

Rockwell Automation Publication 750-RM002B-EN-P - September 2013 107
Feedback and I/O Chapter 2
Analog Scaling
[Anlg In
n Lo]
[Anlg In n Hi]
A scaling operation is performed on the value read from an analog input to
convert it to units usable for some particular purpose. Control the scaling by
setting parameters that associate a low and high analog value (in volts or mA)
with a low and high target (in Hz).
Example 1
• P255 [Anlg In Type], Bit 0 = “0” (Voltage)
• P545 [Spd Ref A Sel] = “Analog In 1”
• P547 [Spd Ref A AnlgHi] = 60 Hz
• P548 [Spd Ref A AnlgLo] = 0 Hz
• P61 [Anlg In1 Hi] = 10V
• P62 [Anlg In1 Lo] = 0V
This is the default setting, where 0V represents 0 Hz and 10V represents 60 Hz
providing 1024 steps (10 bit analog input resolution) between 0 and 60 Hz.
Example 2
Consider the following setup:
• P255 [Anlg In Type], Bit 0 = “0” (Voltage)
• P545 [Spd Ref A Sel] = “Analog In 1”
• P61 [Anlg In1 Hi] = 10V
• P62 [Anlg In1 Lo] = 0V
• P547 [Spd Ref A AnlgHi] = 60 Hz
• P548 [Spd Ref A AnlgLo] = 0 Hz
• P520 [Max Fwd Speed] = 45 Hz
• P522 [Min Fwd Speed] = 15 Hz
10
9
8
7
6
5
4
3
2
1
0
0 10 20 30 40 50 60
Output Hertz
Inpu
t V
ol
ts