Mitsubishi Electric 800 Series Instruction Manual page 311

(D) Operation command and frequency command
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
Pr. 386
(Hz)
0Hz
0
Pr. 385
 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 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" and Pr.384 ≠ "0"), terminal 2 analog input becomes
invalid.
Speed synchronized operation by pulse input/output
Inverter (master)
JOG
Pulse train
output

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
2
0.75 mm ), connect the terminal JOG to the terminal PC by an external pull-up resistor. The table below shows the reference resistance values
for wiring length.
Wiring length
Pull-up resistor
Load current (reference)
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 load 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.
310
PARAMETERS
Limit value
Input pulse
(pulse/s)
Maximum input pulse
Pull up
resistor
Speed
command
FM
SD
Less than 10 m 10 to 50 m
Not required 1 kΩ
10 mA 35 mA
To next inverter (slave)
∗1
PC
Pulse train
input
JOG
Pulse train
output
SD
50 to 100 m
470 Ω
65 mA
Speed
command
FM
To next inverter (slave)
SD