Mitsubishi Electric FR-A820-00046 Instruction Manual page 526

(M) Monitor display and monitor output signal
Terminal FM pulse train output (Pr. 291)
Two kinds of pulse trains can be output to the terminal FM.
● When Pr. 291 "Pulse train I/O selection" = "0 (initial value) or 1", output is made from FM, with
maximum of 8 V DC and 2400 pulses/s.
The pulse width can be adjusted by using the operation panel or parameter unit and calibration
parameter C0 (Pr. 900) FM/CA terminal calibration.
● Commands can be sent (such as inverter output frequency) by connecting a 1 mA full-scale DC
ammeter or a digital meter.
Fig. 5-155:
Not needed when the operation panel or parameter unit is used for calibration.
Use a calibration resistor when the indicator (frequency meter) needs to be calibrated by a
neighboring device because the indicator is located far from the inverter.
However, the frequency meter needle may not deflect to full-scale if the calibration resistor is
connected. In this case, calibrate additionally with the operation panel or parameter unit.
In the initial setting, 1 mA full-scale and 1440 pulses/s terminal FM are used at 60 Hz.
5 - 346
Inverter
24 V
2.2K
3.3K
FM
20K
SD
Indicator
1mA full-scale
analog meter
1 mA
FM
(+)
Calibration
resistor
SD
Pulse width T1: Adjust using calibration parameter C0
Pulse cycle T2: Set with Pr. 55 (frequency monitor)
Set with Pr. 56 (current monitor)
Indicating the FM output
Fig. 5-154:
FM output circuit
(-) T1
8 V DC
T2
Parameters
(Digital indicator)
1440 pulses/s (+)
FM
SD
I002611E
(-)
I002612E