Toshiba TOSVERT VF-nC3 Instruction Manual page 139

 (D-gain adjustment parameter)
This parameter adjusts the differential gain level during PID control. This gain increases the speed of
response to a rapid change in deviation (difference between the process quantity and the amount of
feedback).
Note that setting the gain more than necessary may cause great fluctuations in output frequency, and
thus operation to become unstable.
Previous deviation - current deviation
Assign an input terminal function 52 (PID integral/derivative) to an input terminal, when that input
terminal is ON, it is possible to calculate integral/derivative amounts always as 0 (zero).
5) Adjusting feedback input
To use external analog setting (VIB) or feedback input (VIA), perform voltage-scaling adjustments (input point
setting) as required. See Section 6.5.2 for further details.
If the feedback input data is too small, voltage-scaling adjustment data can also be used for gain adjustment.
Example of 0 - 10 Vdc voltage input
setting (  =  )

(60Hz)

(0Hz)
0V

0%
VI input value
6) Setting the time elapsed before PID control starts
You can specify a waiting time for PID control to prevent the inverter from starting PID control before the
control system becomes stable, for example, after start-up.
The inverter ignores feedback input signals, carries out operation at the frequency determined by the amount
of processing for the period of time specified with  and enters the PID control mode after a lapse of
the specified time.
Feedback amount
Example of 0 - 5 Vdc voltage input
setting (  =  )

(60Hz)

(0Hz)
0V
10V


0%
100%
F-35
Large differential gain
Small differential gain
Example of 4 - 20 Adc voltage input
setting (  =  )

(60Hz)

5V
(0Hz)

100%
VI input value
E6581595
Time
4mA 20mA
 
20% 100%
VI input value
6