# Mitsubishi Electric FR-A820-00046 Instruction Manual Page 464

(D) Operation command and frequency command
Pulse train input specification
Item
Supported pulse method
HIGH input level
LOW input level
Maximum input pulse rate
Minimum input pulse width
Maximum wiring length
(reference value)
Detection resolution
Tab. 5-114: Pulse train input specification
The wiring length of complementary output is dependent on the output wiring specification of
the complementary output unit. The stray capacitance of the wiring changes considerably accord-
ing to how the cable is laid, thus the maximum wiring length is not a guaranteed value.
Adjustment of pulse train and frequency (Pr. 385, Pr. 386)
The frequency during zero input pulse and maximum input pulse can be set with Pr. 385 "Frequency
for zero input pulse" and Pr. 386 "Frequency for maximum input pulse", respectively.
Fig. 5-115:
Limit value = (Pr. 386 - Pr. 385) x 1.1 + Pr. 385
How to calculate the input pulse division scaling factor (Pr. 384)
● The maximum number of pulses can be calculated by the following formula with Pr. 384 "Input
pulse division scaling factor":
Maximum number of pulses (pulse/s) = Pr. 384 × 400 (maximum 100k pulses/s)
(number of detectable pulses = 11.45 pulses/s)
● For example, to run the invert at 0 Hz when pulse train input is zero and at 30 Hz when pulse train
is 4000 pulses/sec, set the inverter as follows:
Pr. 384 = 10 (maximum number of input pulses 4000 pulses/s)
Pr. 385 = 0 Hz, Pr. 386 = 30 Hz (pulse train limit value 33 Hz)
NOTE
The priority of the frequency command by the external signals is "Jog operation > multi-speed
operation > terminal 4 analog input". When pulse train input is enabled (Pr. 291 = "1, 11, 21, 100"
5 - 284
Open collector output
method
Complementary output
method
60 Hz/50 Hz
Pr. 386
(Hz)
0 Hz
0
Pr. 385
Specification
Open collector output.
Complementary output. (24 V power supply voltage)
20 V or more (voltage between JOG and SD)
5 V or less (voltage between JOG and SD)
100 kpps
2.5 μs
2 kΩ (typ)/10 mA (typ)
2
10 m (0.75 mm
/twisted pair)
100 m (output resistance 50 Ω)
1/3750
Limit value
Input pulse
(pulse/s)
Maximum input pulse
Parameters
I002575E