# Mitsubishi Electric FR-F820-00046 Instruction Manual Page 248

Fr-f800 series.

 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.
60Hz(50Hz)
Pr. 386
(Hz)
0Hz
0
Pr. 385
*1
Limit value = (Pr.386 - Pr.385) × 1.1 + Pr.385
 How to calculate the input pulse division scaling factor (Pr.384)
The maximum number of input 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 given by the external signals is as follows: JOG operation > multi-speed operation >
terminal 4 analog input > pulse train input. When pulse train input is enabled (Pr.291 = "1, 11, 21, or 100" and Pr.384 ≠ "0"),
 Speed synchronized operation by pulse input/output
Inverter (master)
JOG
Pulse train
output
*1
When the wiring length between FM and JOG is long, the influence of stray capacitance causes the pulse to flatten out and prevents the input
pulse from being recognized. When the wiring length is long (10 m or longer of shielded twisted pair cable with a recommended cable size of 0.75
2
mm
), connect between terminal JOG and terminal PC with an external pull-up resistor. The following table shows the reference resistance values
for wiring length.
Wiring length
Pull-up resistor
The stray capacitance of the wiring changes considerably according to how the cable is laid, thus the above wiring lengths are not guaranteed
values.
When using a pull-up/down resistor, check the permissible power of the resistor and the permissible load current (terminal PC: 100 mA, high-
speed pulse train output: 85 mA), and use within the permissible range.
• Setting "100" in Pr.291 allows the use of the entire pulse train input for the pulse train output (via terminal FM) just as they
are.
Connecting in a daisy chain enables speed synchronized operation of multiple inverters.
• Set Pr.384 to "125" for inverters that receive pulse train since the maximum pulse train output is 50k pulses/s.
• The maximum number of input pulses should be 50k pulses/s.
Limit value
Input pulse
(pulse/s)
Maximum input pulse
To next inverter (slave)
Pull up
*1
resistor
PC
Speed
command
FM
JOG
SD
SD
Less than 10 m
Not required
10 mA
Speed
Pulse train
command
input
Pulse train
output
10 to 50 m
1 kΩ
35 mA
5.6 (D) Operation command and frequency command
FM
To next inverter (slave)
SD
50 to 100 m
470 Ω
65 mA
5. PARAMETERS
1
2
3
4
5
6
7
8
9
10
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