Pid Control - Hitachi X200 Series Instruction Manual

3 22
3 22

PID Control

When enabled, the built-in PID loop calculates an ideal inverter output value to cause a
loop feedback process variable (PV) to move closer in value to the set point (SP). The
frequency command serves as the SP. The PID loop algorithm will read the analog input
for the process variable (you specify the current or voltage input) and calculate the
output.
A scaled factor in A075 lets you multiply the PV factor, converting it into
engineering units for the process.
Proportional, integral, and derivative gains are all adjustable.
See
Func.
Code
A071 PID enable
PID Mode
A072 PID proportional gain
PID P
A073 PID integral time constant
PID I
A074 PID derivative time constant
PID D
A075 PV scale conversion
PID Cnv
A076 PV source setting
PID INP
A077 Reverse PID action
PID MINUS
A078 PID output limit
PID Vari
NOTE: The setting A073 for the integrator is the integrator's time constant Ti, not the
gain. The integrator gain Ki = 1/Ti. When you set A073 = 0, the integrator is disabled.
"PID Loop Operation" on page 4-56
"A" Function
Name /
SRW Display
OFF
0001.0
0001.0s
000.00s
001.00%
OI
OFF
0000.0%
for more information.
Description
Enables PID function,
two option codes:
00 PID Disable
01 PID Enable
Proportional gain has a range of
0.2 to 5.0
Integral time constant has a
range of 0.0 to 150 seconds
Derivative time constant has a
range of 0.0 to 100 seconds
Process Variable (PV), scale
factor (multiplier), range of 0.01
to 99.99
Selects source of Process Variable
(PV), option codes:
00 [OI] terminal (current in)
01 [O] terminal (voltage in)
02 ModBus network
10 Calculate function output
Two option codes:
00 PID input = SP-PV
01 PID input = -(SP-PV)
Sets the limit of PID output as
percent of full scale,
range is 0.0 to 100.0%
Defaults
Run
Mode -FE -FU
Units
Edit
(EU) (USA)
00 00
1.0 1.0
1.0 1.0 sec
0.00 0.00 sec
1.00 1.00
00 00
00 00
0.0 0.0 %