Fine Adjustment Of Frequency Setting Signal - Toshiba TOSVERT VF-nC3 Instruction Manual

6.5.4

Fine adjustment of frequency setting signal

 : VI voltage bias
 : VI voltage gain
 Function
These parameters are used to fine adjust the relation between the frequency setting signal input
through the analog input terminal VI and the output frequency.
Use these parameters to make fine adjustments after making rough adjustments using the
parameters f201 to f204.
The figure below shows the characteristic of the frequency setting signal input through the VI terminal and
that of the output frequency.
Output frequency (Hz)
Maximum frequency

* Bias adjustment of VI input terminal (f470)
To give leeway, the inverter is factory-adjusted by default so that it will not produce an output until a
certain amount of voltage is applied to the VI input terminal. If you want to reduce the leeway, set f470
to a larger value. Note that specifying a too large value may cause an output frequency to be output, even
though the operation frequency is 0 (zero) Hz.
* Gain adjustment of VI input terminal (f471)
The inverter is factory-adjusted by default so that the operation frequency can reach the maximum
frequency, even though the voltage and current to the VI input terminal are below the maximum levels. If
you want to adjust the inverter so that it will output the maximum frequency at the maximum voltage and
current, set f471 to a smaller value. Note that specifying a too small value may cause the operation
frequency not to reach the maximum frequency, even though the maximum voltage and current are
applied.
Large
Small
0
0%
0V
4mA
Frequency setting signal（ VI input value）
F-17
Large

Small
Default setting
100%
10Vdc
20mAdc
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