Analog input operation, Analog input operation 4–53 – Hitachi L2002 User Manual

Page 197

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background image

L200

2

Inverter

Oper

ations

and Monitor

ing

4–53

Analog Input Operation

The L200

2

inverters provide for analog input

to command the inverter frequency output
value. The analog input terminal group
includes the [L], [OI], [O], and [H] terminals
on the control connector, which provide for
Voltage [O] or Current [OI] input. All analog
input signals must use the analog ground [L].

If you use either the voltage or current analog
input, you must select one of them using the
logic input terminal function [AT] analog
type. If terminal [AT] is OFF, the voltage
input [O] can command the inverter output
frequency. If terminal [AT] is ON, the current
input [OI] can command the inverter output
frequency. The [AT] terminal function is
covered in

“Analog Input Current/Voltage

Select” on page 4–23

. Remember that you

must also set A001 = 01 to select analog input
as the frequency source.

NOTE: If no logic input terminal is configured for the [AT] function, then inverter sums
the voltage and current input to determine the desired input value.

Using an external potentiometer is a common
way to control the inverter output frequency
(and a good way to learn how to use the
analog inputs). The potentiometer uses the
built-in 10V reference [H] and the analog
ground [L] for excitation, and the voltage
input [O] for the signal. By default, the [AT]
terminal selects the voltage input when it is OFF. Take care to use the proper resistance
for the potentiometer, which is 1 to 2 k Ohms, 2 Watts.

Voltage Input – The voltage input circuit uses
terminals [L] and [O]. Attach the signal
cable’s shield wire only to terminal [L] on the
inverter. Maintain the voltage within specifi-
cations (do not apply negative voltage).

Current Input – The current input circuit
uses terminals [OI] and [L]. The current
comes from a sourcing type transmitter; a
sinking type will not work! This means the
current must flow into terminal [OI], and
terminal [L] is the return back to the transmit-
ter. The input impedance from [OI] to [L] is
250 Ohms. Attach the cable shield wire only to terminal [L] on the inverter.

+V Ref.

A GND

Voltage input

Current input

L

H O OI

AM

+ –

4-20 mA, AT=ON

0-10 V, AT=OFF

[AT]

V/I input

select

Freq.

setting

L

H O OI

AM

A001

1 to 2k

Ω, 2W

L

H O OI

AM

+ –

4 to 19.6 mA DC,
4 to 20 mA nominal

0 to 9.6 VDC,
0 to 10V nominal

See I/O specs on page

4–6

.

L

H O OI

AM

L

H O OI

AM

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