Analog input time constant (Pr.74)
• Use this parameter to eliminate noise on the frequency setting circuit.
• Increase the filter time constant if the operation is unstable due to noise or other factors.
If the setting is too large, response becomes slow. (The time constant can be between 0 and 8, which are about 5 ms to 1
Analog speed command input time constant (Pr.822, Pr.832)
• Use Pr.822 Speed setting filter 1 to set the primary delay filter time constant to the external speed command (analog
input command). Increase the setting of the time constant to allow delays in follow-up of the speed command or when the
analog input voltage is unstable.
• Use Pr.832 Speed setting filter 2 to change the time constant to use one inverter to switch operation between two or more
• Pr.832 Speed setting filter 2 is enabled when the RT signal is ON.
Analog speed command input offset adjustment (Pr.849)
• Use this parameter to set a range in which the motor is stopped for prevention of incorrect motor operation in a very low
speed rotation when the speed command is an analog input.
• The voltage range is offset according to the setting in Pr.849 Analog input offset adjustment, assuming that 100%
corresponds to zero.
100% < Pr.849 ...... Positive side
100% > Pr.849 ...... Negative side
The detailed calculation of the offset voltage is as described below:
Offset voltage [V] = Voltage at the time of 100% (5 V or 10 V
It depends on the Pr.73 setting.
• The analog input filter is invalid (no filter) during PID control operation.
Parameters referred to
Pr.73 Analog input
Pr.125, C2 to C4 (bias and gain of the terminal 2 frequency
5.9 (T) Multi-function input terminal parameters
according to Pr.125
and C2 to C4
Slope does not
(10V or 5V)
) × (Pr.849 - 100) / 100