“A” Group: Standard Functions
Configur
ing Dr
iv
e
P
a
ra
meters
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 setpoint (SP). The current
frequency command serves as the SP. The PID loop algorithm will read the analog input for the
process variable (you specify either 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.
• Optional – You can assign an intelligent input terminal the option code 23, PID Disable.
When active, this input disables PID operation. See
“Intelligent Input Terminal Overview”
on page 3–51
.
• See
“PID Loop Operation” on page 4–75
for more information.
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.
Func.
Code
Name/
Description
Keypad
Range and Settings
Defaults
Run
Mode
Edit
Lo Hi
SRW
OPE
FEF2
FE2
(EU)
FUF2
FU2
(USA)
FF2
F2
(Jpn)
A071
PID Enable
OFF
00
PID operation OFF
00
00
00
✘ ✔
ON
0 1
PID operation ON
✘ ✔
R-ON
02
PID operation ON with inverted output
✘ ✔
A072
PID proportional gain
0.2 to 5.0
1.0
1.0
1.0
✔ ✔
A073
PID integral time constant
0.0 to 999.9, 1000. to 3600. (seconds)
1.0
1.0
1.0
✔ ✔
A074
PID derivative time constant
0.0 to 99.99, 100.0 (seconds)
0.0
0.0
0.0
✔ ✔
A075
PV scale conversion
0.01 to 99.99, 100.0 (seconds)
1.00
1.00
1.00
✘ ✔
Process Variable (PV) scale factor (multiplier)
✘ ✔
A076
PV source setting
OI
00
[OI] terminal (current input)
00
00
00
✘ ✔
Selects source of Process
Variable (PV)
O
0 1
[O] terminal (voltage input)
✘ ✔
COM
02
Communication input
✘ ✔
PLS
03
Pulse train frequency input
✘ ✔
MATH
1 0
CALCULATE function output
✘ ✔
A077
Reverse PID Action
OFF
00
PID input = SP – PV (normal)
00
00
00
✘ ✔
Changes response to error
ON
0 1
PID input = –(SP – PV) (reverse)
✘ ✔
A078
PID output limit
Range is 0.0 to 100.0
0.00
0.00
0.00
✘ ✔
A079
PID feed forward select
no
00
Disable
00
00
00
✘ ✔
O
0 1
[O] terminal (voltage input)
✘ ✔
OI
02
[OI] terminal (current input)
✘ ✔
O2
03
[O2] terminal (voltage input)
✘ ✔
