Hitachi WJ200-001L, Инструкция по эксплуатации, Страница: 277 / 680

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Analog Input Disconnect Detect
This feature is useful when the inverter receives a speed reference from an external
device. Upon input signal loss at either the [O] or [OI] terminal, the inverter normally
just decelerates the motor to a stop. However, the inverter can use the intelligent
output terminal [Dc] to signal other devices that a signal loss has occurred.
Voltage signal loss at [O] terminal -
Parameter

is the Start Frequency
Adjustment. It sets the beginning (minimum) output frequency when the speed
reference source is greater than zero. If the analog input at terminal [O] is less than
the Start Frequency, the inverter turns ON the [Dc] output to indicate a signal loss
condition.
Current signal loss at [OI] terminal -
The [OI] terminal accepts a 4mA to 20mA signal,
with 4mA representing the beginning of the input range. If the input current falls
below 4mA, the inverter applies a threshold to detect signal loss.
Note that a signal loss is not an inverter trip event. When the analog input value is again above
the

value, the [Dc] output turns OFF. There is no error condition to clear.
Option
Code
Terminal
Symbol
Function Name State Description

ODc Analog voltage Input
Disconnect Detect ON when signal loss is detected on [O] input
OFF when no signal loss is detected on [O] input

OIDc Analog current Input
Disconnect Detect ON when signal loss is detected on [OI] input
OFF when no signal loss is detected on [OI] input
Valid for inputs:
11, 12, AL0
– AL2
Example for terminal [11] (default output
configuration shown
– see
page 3-89 ):
Example for terminal [AL0], [AL1], [AL2] (requires
output configuration
– see
page 4-51 and 3-91 ):
See I/O specs on
page 4-6
Required settings

=

,

Notes:

The [Dc] output can indicate an analog signal
disconnect when the inverter is in Stop Mode, as
well as Run Mode.

The example circuit for terminal [11] drives a relay
coil. Note the use of a diode to prevent the
negative-going turn-off spike generated by the coil
from damaging the inverter’s output transistor.
RY
Inverter output
terminal circuit
CM2 11
DC
AL1
Power
supply
Load
AL0 AL2
Inverter logic
circuit board DC