Toshiba VF-A7 instruction manual Operation frequency, Start-up frequency and End frequency

6.7 Operation frequency

6.7.1 Start-up frequency and End frequency

 ：Start-up frequency

 ：Stop frequency

・Function

The frequency set with the parameter  is put out immediately.

These parameters are used if the acceleration/deceleration time causes a delay in the response of the starting torque. It is advisable to set these frequencies between 0.5 and 2 Hz (at a maximum of 5 Hz). This setting reduces the slippage of motor below the rated value to prevent over-current. If 0 speed torque is needed(pt = ,), set , at .

･At startup: frequency set with  is put out immediately.

･At stop: The output frequency drops to 0 Hz immediately by the frequency set with .

[Parameter setting]

Title	Function	Adjustment range	Default setting
	Start-up frequency	～ [Hz]	
	Stop frequency	～ [Hz]	

Output frequency [Hz]

Start-up frequency Stop frequency





０ [s]

Note) Set these parameters so that the start-up frequency  is higher than the stop frequency . If the -set frequency is lower than the -set frequency, the reference frequency must be higher than the -set frequency to start the motor.

6.7.2 Operating by means of reference signals

 ：Run frequency

 ：Run frequency hysteresis

・Function

The start and stop of the motor can be controlled simply by giving frequency setting signals. [Parameter setting]

Title	Function		Adjustment range	Default setting
	Run frequency		～	
	Run frequency	hysteresis	～ [Hz]	

Output frequency [Hz] 

 ＋  

The motor starts to accelerate when the frequency setting signal reaches point B, while it starts to decelerate and stop when the frequency setting signal falls below point A.



－



0 A B 100 Frequency reference [%]

6.7.3 0Hz dead band frequency

 ：0Hz dead band frequency

・Function

In order to fixe the motor axis by the control with a sensor, you may set frequency reference as 0[Hz] by the analog input etc.. But it may be set to 0[Hz] neither

by the drift nor offset. In such a case, this function sets frequency instructions to 0[Hz] certainly. When frequency reference is smaller than -set value, frequency reference is set to 0[Hz].

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