AutomationDirect DURAPULSE GS3-2010, User Manual

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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
0V
-10V
0mA
4mA
10V
10V
20mA
20mA
5V
0V
10mA
12mA
Maximum
Frequency
Reference
Maximum
Output
Frequency
Positive Offset
0Hz
11.5Hz
25.6Hz
30Hz
39.6Hz
60Hz
Chapter 4: AC Drive Parameters
DURA
PULSE AC Drive User Manual 1st Ed. Rev. D 05/2013