Pid Control - Hitachi SJ200 Series Instruction Manual

3–22
"A" Group: Standard Functions

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 setpoint (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 scale factor in A075 lets you multiply the PV by a factor, converting it into
engineering units for the process.
• Proportional, integral, and derivative gains are all adjustable.
• See "PID Loop Operation" on page 4–54
Func.
Code SRW Display
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 0000.0%
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.
"A" Function
Name /
Enables PID function,
two option codes:
OFF
00... PID Disable
01... PID Enable
Proportional gain has a range
of 0.2 to 5.0
0001.0
Integral time constant has a
range of 0.0 to 150 seconds
0001.0s
Derivative time constant has a
range of 0.0 to 100 seconds
000.00s
Process Variable (PV) scale
factor (multiplier), range of
001.00%
0.01 to 99.99
Selects source of Process
Variable (PV), option codes:
OI
00... [OI] terminal (current in)
01... [O] terminal (voltage in)
02... ModBus network
03... Calculate function output
Two option codes:
00... PID input = SP – PV
OFF
01... PID input = –(SP – PV)
Sets the limit of PID output as
percent of full scale,
range is 0.0 to 100.0%
for more information.
Run
Mode
Description
Edit
Defaults
–FEF –FU
Units
(EU) (USA)
00 00 —
1.0 1.0 —
1.0 1.0 sec.
0.0 0.0 sec.
1.00 1.00 —
00 00 —
00 00 —
0.0 0.0 %