Quantizing may be used when the noise level is high in the analog input
signal. The inverter output frequency changes in consistent intervals (steps)
based on measuring (quantizing) the height (value) of the analog input
signal. Delicate control (resolution) of the output frequency is not as good
compared to standard resolution of 0.1%. Parameter values for quantizing
refer to a percentage based on the maximum input. Therefore, when IN-17
is set to 1% of the analog maximum input of 10 V and with a maximum
frequency of 60 Hz, the output frequency will increase or decrease by 0.6
Hz per 0.1V difference.
With quantizing applied, changes to the inverter output frequency for analog
signal increase and analog signal decrease are treated differently. When
the input signal increases, the output frequency starts increasing when the
height becomes equivalent to 3/4 of the quantizing value. From then on, the
output frequency increases according to the quantizing value. When the
input signal decreases, the output frequency starts decreasing when the
height becomes equivalent to 1/4 of the quantizing value.
Although the noise can be reduced using the low-pass filter (IN-07), the
inverter output response to the input signal takes longer with higher filter
times. It can become difficult to control the output frequency when the input
signal is delayed, a period of long pulse (ripple) may occur on the output
frequency.
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