Hitachi L100 Series, Инструкция по эксплуатации

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L100 Inverter
Oper
ations
and Monitor
ing
4–29
Analog Input Operation
The L100 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 4–18 . Remember that you
must also set A_01 = 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
12 11 L H O OI FM CM2
+ –
4-20 mA, AT= ON
0-10 V, AT= OFF
[AT]
V/I input
select
Frequency
setting
A 01
12 11 L H O OI FM CM2
1 to 2k
Ω
, 2W
12 11 L H O OI FM CM2
+ –
4 to 19.6 mA DC,
4 to 20 mA nominal
0 to 9.6 VDC,
0 to 10V nominal
12 11 L H O OI FM CM2
12 11 L H O OI FM CM2
See I/O specs on page 4–6 .