User Manual Instruction Manual

Application Notes 13-47
This is an application that only requires 30 Hz as a maximum output frequency, but is
still configured for full 10 volt input. The result is that the resolution of the input has
been doubled, providing only 3 Hz change per input volt (Configuration #1 is 6
Hz/Volt).
Analog Scaling
13.19.3.3 Configuration #3:
• Anlg In Config (320), bit 0 = “1” (Current)
• Speed Ref A Sel (90) = “Analog In 1”
• Speed Ref A Hi (91) = 60 Hz
• Speed Ref A Lo (92) = 0 Hz
• Analog In 1 Hi (322) = 20 mA
• Analog In 1 Lo (323) = 4 mA
This configuration is referred to as offset. In this case, a 4-20 mA input signal provides
0-60 Hz output, providing a 4 mA offset in the speed command.
Analog Scaling
Speed Ref A Sel (90) = “Analog In 1”
Analog In 1Hi (322)
10V
Speed Ref A Hi (91)
30 Hz
Analog In 1Lo (323)
0V
Speed Ref A Lo (92)
0 Hz
2
4
6
8
10
12
601218
Output Hertz
Input Volts
24 30 36 42 48 54 60
Speed Ref A Sel (90) = “Analog In 1”
Analog In 1Hi (322)
20 mA
Speed Ref A Hi (91)
60 Hz
Analog In 1Lo (323)
4 mA
Speed Ref A Lo (92)
0 Hz