4.2.49 Meter (frequency meter) calibration (Pr. 900)
(200V class, 100V class)
Pr. 900 "FM terminal calibration"
z By using the control panel or parameter unit, you can calibrate a meter connected to
terminal FM to full scale deflection.
z Terminal FM provides the pulse output. By setting Pr. 900, you can calibrate the
meter connected to the inverter from the parameter unit without providing a
z You can display a digital value on a digital counter using the pulse train signal from
terminal FM. A 1440 pulses/sec. output is provided at the full scale value as
explained in the section of Pr. 54. When the running frequency has been selected
for monitoring, the ratio of this FM terminal output frequency can be set in Pr. 55.
Pulse width T1
Pulse period T2
(1)Calibration of terminal FM
1) Connect a meter (frequency meter) across inverter terminals FM-SD.
(Note the polarity. FM is the positive terminal.)
2) When a calibration resistor has already been connected, adjust the resistance to
"0" or remove the resistor.
3) Set any of "0 to 2" in Pr. 54.
When the running frequency or inverter output current has been selected as the
output signal, preset in Pr. 55 or Pr. 56 the running frequency or current at which
the output signal is 1440Hz.
At this 1440 pulses/sec., the meter normally deflects to full scale.
1mA full scale
: Adjusted with Pr. 900
: Set in Pr. 55 (frequency monitoring)
Set in Pr. 56 (current monitoring)
Pr. 54 "FM terminal function
Pr. 55 "frequency monitoring
Pr. 56 "current monitoring
( − )
( + )
Note : The parameter is factory-set to 1mA
full-scale or 1440 pulses/sec. FM
output frequency at 60Hz.