MITSUBISHI ELECTRIC FR-S520 - Manual (Page 44)

35
1
Output waveform of terminal FM
The output signal of terminal FM has a pulse waveform as shown in the table below
and the number of its pulses is proportional to the inverter output frequency.
The output voltage (average voltage) is also proportional to the output frequency.
Terminal FM Output Voltage
Specifications
Output
waveform
Calibration parameter C1 (Pr. 900)
8V
Number
of output
pulses
(pulses/
second)
Max. 2400 pulses/s
Set a full-scale value which
achieves 1440 pulses/s.
Pr. 55: frequency monitoring
reference
Pr. 56: current monitoring
reference
Output
voltage
0 to 8VDC max. (*1)
(Approx. 5V at 1440 pulses/s)
Inverter
24V
SD
FM
FM
Example of Inverter and Frequency
Meter
*1. 0.5V or less when a DC ammeter of 300
Ω
or less internal resistance is connected
to measure the output voltage.
Adjustment
Analog meter
To adjust the reading of an analog indicator (ammeter), turn the calibration resistor
to change the current.
When using the operation panel or parameter unit for adjustment, change the pulse
width of the output waveform (calibration parameter "C1") (adjust the current through
the adjustment of the output voltage) to adjust the reading. (For details, refer to page
111.)
REMARKS
It is not recommended to use a voltage type indicator because it is easily affected
by a voltage drop, induction noise, etc. and may not provide correct reading if the
wiring distance is long.