Pre-excitation signal (LX signal)
• When the Pre-excitation/servo ON (LX) signal is turned ON while the motor stops under Real sensorless vector control,
Vector control, or PM sensorless vector control, pre-excitation (zero speed control / servo lock) starts.
• To input the LX signal, set "23" in any of Pr.178 to Pr.189 (Input terminal function selection) to assign the function.
• Changing the terminal assignment using Pr.178 to Pr.189 (Input terminal function selection) may affect the other functions.
Set parameters after confirming the function of each terminal.
• Performing pre-excitation (by using the LX or X13 signal) during torque control (under Real sensorless vector control) may
rotate a motor at a low speed even though a start command (STF or STR) is not input. The inverter at a start command ON
may also rotate the motor at a low speed even though a speed limit value is set to zero It must be confirmed that the motor
running will not cause any safety problem before performing pre-excitation.
• Note that during the pre-excitation operation, a voltage is applied to the motor even with the FWD/REV indicator OFF on the
• When offline auto tuning (Pr.96 Auto tuning setting/status = "1, 11, or 101") is performed during pre-excitation operation,
pre-excitation is disabled.
• During the orientation operation, do not set "0 or 8888" in Pr.11 and do not set "0" in Pr.12. The motor may not stop
• Install a mechanical brake to make an emergency stop or to stay stopped for a long time.
Wait until the machine stops completely, and fix the motor with a mechanical brake, then turn the LX signal (pre-
Parameters referred to
Pr.178 to Pr.189 (Input terminal function
Pr.422 Position control gain, Pr.1298 Second position control
5.16.9 Output stop function
The motor coasts to a stop (inverter output is shutoff) when the inverter output frequency falls to Pr.522 setting or lower.
Output stop frequency
• When both of the frequency setting signal and output frequency fall to the frequency set in Pr.522 or lower, the inverter
stops the output and the motor coasts to a stop.
• The motor re-starts when the frequency setting signal exceeds Pr.522 + 2 Hz and is accelerated at the Pr.13 Starting
frequency (0.01 Hz under PM sensorless vector control).
5.16 (G) Control parameters
When Pr. 850 = 1
Zero speed control
0 to 590 Hz
Set the frequency to start coasting to a stop (output shutoff).