Toshiba MITOS VT6 AIR User Manual page 10

The meaning f the several numbers is the following one:
1. moment in which there is the start
2. moment in which the controlled variable is catches up the set-point and starts the PID regulation
3. moment in which there is the stop
4. equal time to the value of the Delay ACC/DEC PID after which PID regulation enter however in function
The figure "a" is relative to the case in which between the start and stop inverter the controlled variable never doesn't
catch up the set point.
The figure "b" is relative to the case in which between the start and stop inverter the controlled variable catch up the set
point ( in correspondence of the point 2).
The purpose of the two couples of different ramps in manual and automatic is to allow a slower answer during the start-
up, a quicker one when you are working at full speed.
If the system can be led to instability (permanent waver), an empirical way to find the values of integrative, derivative
and proportional constants is the following one:
1) Set Ki and Kd to zero
2) Staring from Kp low, increase Kp slowly to reach a waver of controlled variable
3) Reduce Kp at the half of precedent value
4) If necessary, increase Ki to bring to zero errors in stationary system
5) If necessary, increase Kd to speed up the answer
If you change the unit of measurement to the controlled variable, you need to calibrate again the PID parameters.
02/10/2015 10 / 17 Manual_MITOS_VT6_AIR_ver3p3_eng