4–53
Example 7: Positive Offset with Reduced Analog Gain
This example illustrates how to provide a positive offset of the Analog Input, while
using the full scale of the potentiometer or other analog device. At the same time,
the Maximum Frequency Reference is limited by reducing the Analog Input Gain.
When the analog signal is at its lowest value, the set-point frequency will be at
11.5Hz. When the analog signal is at its maximum value, the set-point frequency
will be 39.6Hz.
• Minimum Frequency Reference = 11.5 Hz
• Maximum Frequency Reference = 39.6 Hz
Calculations
A) Max Output Frequency = (1750 rpm / 1750 rpm) x 60 Hz = 60 Hz
B) Analog Offset % = (11.5 Hz / 60 Hz) x 100 = 19.2%
C) Analog Gain % = ((39.6 – 11.5) / 60) x 100 = 46.8%
D) Mid-point Frequency = ((39.6 – 11.5) / 2) + 11.5 = 25.6 Hz
Parameter Settings
P4.01: 01 – Positive Analog Input Offset Polarity
P4.02: 19.2 – 19.2% Analog Input Offset
P4.03: 46.8 – 46.8% Analog Input Gain
P4.04: 00 (default ) – Forward Motion Only
Results
To Next Page
Loading...