Hitachi L2002 PID Control, •See “PID Loop Operation” on page 4–56for more information, •Proportional, integral, and derivative gains are all adjustable

3–24

“A” Group: Standard Functions

PID Control

Configuring Drive Parameters

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 4–56 for more information.

		“A” Function		Run		Defaults
				Mode
Func.	Name /				–FE(F)	–FU
			Description	Edit			Units
Code	SRW Display			Lo Hi	(EU)	(USA)
A071	PID Enable		Enables PID function,	✘ ✔	00	00	—
			two option codes:
	PID Mode	OFF
			00... PID Disable
			01... PID Enable
A072	PID proportional gain		Proportional gain has a range	✔ ✔	1.0	1.0	—
			of 0.2 to 5.0
	PID P	0001.0
A073	PID integral time		Integral time constant has a	✔ ✔	1.0	1.0	sec.
	constant		range of 0.0 to 150 seconds
	PID I	0001.0s
A074	PID derivative time		Derivative time constant has a	✔ ✔	0.0	0.0	sec.
	constant		range of 0.0 to 100 seconds
	PID D	000.00s
A075	PV scale conversion		Process Variable (PV) scale	✘ ✔	1.00	1.00	—
			factor (multiplier), range of
	PID Cnv	001.00%
			0.01 to 99.99
A076	PV source setting		Selects source of Process	✘ ✔	00	00	—
			Variable (PV), option codes:
	PID INP	OI
			00... [OI] terminal (current in)
			01... [O] terminal (voltage in)
			02... ModBus network
			03... Calculate function output
A077	Reverse PID action		Two option codes:	✘ ✔	00	00	—
			00... PID input = SP – PV
	PID MINUS	OFF
			01... PID input = –(SP – PV)
A078	PID output limit		Sets the limit of PID output as	✘ ✔	0.0	0.0	%
			percent of full scale,
	PID Vari 0000.0%
			range is 0.0 to 100.0%

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.