Analog Output Operation - Hitachi L2002 Instruction Manual

Analog Output Operation

In inverter applications it is useful to monitor
the inverter operation from a remote location or
from the front panel of an inverter enclosure. In
some cases, this requires only a panel-mounted
volt meter. In other cases, a controller such as a
PLC may provide the inverter's frequency
command, and require inverter feedback data
(such as output frequency or output current) to
confirm actual operation. The analog output
terminal [AM] serves these purposes.
The inverter provides an analog voltage output on terminal [AM] with terminal [L] as
analog GND reference. The [AM] can output inverter frequency or current output value.
Note that the voltage range is 0 to +10V (positive-going only), regardless of forward or
reverse motor rotation. Use C028 to configure terminal [FM] as indicated below.
Func. Code
C028
The [AM] signal offset and gain are adjustable, as indicated below.
Func.
B080 [AM] analog signal gain
C086 [AM] terminal offset tuning
The graph to the right shows the effect of the
gain setting. To calibrate the [AM] output for
your application, follow the steps below:
1. Verify that the inverter is in Stop Mode.
2. Use C086 to adjust the offset voltage. The
factory default (0V) is the correct value for
most cases. Otherwise, you can have a
positive voltage at zero speed or current.
3. Run the motor at the full scale speed.
a. If [AM] represents output frequency, use
B080 to set the voltage for full scale
output (up to 10V).
b. If [AM] represents motor current, use B080 to set the voltage for full scale
output. Remember to leave room at the upper end of the range for increased
current when the motor is under heavier loads.
Description
00 Output frequency
01 Output current
Description
L200 Inverter
2
AM H O OI
+
Analog
Voltage
Output
10VDC
full scale,
1mA max
See I/O specs on page 4–6.
Range
0 – Max. frequency (Hz)
0 – 200%
Range Default
0 to 255 100
0 – 10V 0.0
[AM]
B080=200%
10V
5V
0
1/2 full
scale
4–55
L
–
A GND
B080=100%
B080=50%
Hz
Full
or
scale
A
output