# Toshiba Tosvert VF-AS1 Instruction Manual Page 152

The new high-performance inverter.

3) Setting the PID control
In case of controlling the airflow, water flow and pressure, please set the parameter  to ""(Process type PID
control operation)
(1)Please set the parameter (Acceleration time),(deceleration time) to the suitable time for the system.
(2)Please set the following parameters to place limits to the setting value and the control value.
Placing a limit to the process value : The parameter (Process upper limit),  (Process lower limit)
Placing a limit to the PID deviation : The parameter (PID deviation upper limit ),  (PID deviation
lower limit )
Placing a limit to the PID output : The parameter (PID output upper limit ),  (PID output lower limit )
Placing a limit to the output frequency : The parameter (Upper limit frequency ),  (Lower limit frequency )
Adjust PID control gains according to the process value, the feedback input signal and the item to be controlled.
Here are the parameters used to adjust PID control gains.
Title



Proportional (P) gain
The proportional (P) gain set with  is the proportional (P) gain obtained by PID control.
A proportional (P) gain, a factor by which the deviation (difference between the process value and the feedback
value) is multiplied, is used to perform control in such a way as to make a correction in proportion to the deviation.
6
Although setting this gain high is effective in increasing the response speed, setting it excessively high may cause
an unstable operation, such as vibration.
Feedback value
High proportional gain 
Fast response
 Integral (I) gain
The integral (I) gain set with  is the integral (I) gain obtained by PID control.
The integral gain reduces the deviation remaining after proportional control to zero (offsetting of residual deviation).
Although setting this gain high is effective in reducing the residual deviation, setting it excessively high may cause
an unstable operation, such as vibration.
Feedback value
Function
Proportional (P) gain
Integral (I) gain
Differential (D) gain
~
~
~
Low proportional gain 
Slow response
Low integral gain 
Residual deviation
High integral gain 
F-36
E6581442
Default setting



Process value
Time
Process value
Time