AutomationDirect DURAPULSE Series User Manual page 118

Chapter 4: AC Drive Parameters
Example 4: Forward and Reverse Operation
In this example, the potentiometer (or other analog signal device) is programmed
to run a motor full-speed in both forward and reverse directions. The frequency
reference will be 0Hz when the potentiometer is positioned at mid-point of its
scale. Parameter P4.04 must be set to enable reverse motion.
When calculating the values for the Analog Input using reverse motion, the reverse
frequency reference should be shown using a negative (-) number. Pay special
attention to signs (+/-) for values representing reverse motion.
• Minimum Frequency Reference = -60 Hz (reverse)
• Maximum Frequency Reference = 60 Hz
Calculations
A) Max Output Frequency = (1750 rpm / 1750 rpm) x 60 Hz = 60 Hz
B) Analog Offset % = (-60 Hz / 60 Hz) x 100 = -100%
The negative (-) value for the Analog Offset % shows that a negative offset is needed
for P4.01.
C) Analog Gain % = ((60 Hz – (-60 Hz)) / 60 Hz) x 100 = 200%
D) Mid-point Frequency = ((60 Hz – (-60 Hz)) / 2) + (-60 Hz) = 0Hz
Parameter Settings
P4.01: 02 – Negative Input Offset Polarity
P4.02: 100 – 100% Analog Input Offset
P4.03: 200 – 200% Analog Input Gain
P4.04: 01 – Reverse Motion Enable
Results
Maximum Output
4–50 DURA
PULSE
60Hz
Frequency
0Hz
-60Hz
0V
-10V
0mA
4mA
AC Drive User Manual
Forward
Reverse
5V 10V
0V 10V
10mA 20mA
12mA 20mA
1st Ed. Rev. D 05/2013