Hitachi L2002 Multi-speedand Jog Frequency Setting

3–16

“A” Group: Standard Functions

Configuring Drive Parameters

The example graph below shows a typical analog input waveform. The filter removes the noise spikes. When a speed change (such as level increase) occurs, the filter naturally has a delayed response. Due to the deadband feature (A016=17), the final output changes only when the 16-sample average moves past the deadband threshold.

	A016=17	Hz
					Small step-change
	Output freq.
	reference
				Threshold exceeded					+0.1
+0.1
										“0”
16-sample avg. “0”								New deadband
		–0.2	Deadband							–0.2
	Analog input						speed increase given
						noise spikes				t

TIP: The deadband feature is useful in applications that require a very stable output

frequency but use an analog input for the speed reference. Example application: A grinding machine uses a remote potentiometer for operator speed input. After a setting change, the grinder maintains a very stable speed to deliver a uniform finished surface.

Multi-speed and Jog Frequency Setting

The L2002 inverter has the capability to store and output up to 16 preset frequencies to the motor (A020 to A035). As in traditional motion terminology, we call this multi-speed profile capability. These preset frequencies are selected by means of digital inputs to the inverter. The inverter applies the current acceleration or deceleration setting to change from the current output frequency to the new one. The first multi-speed setting is duplicated for the second motor settings (the remaining 15 multi-speeds apply only to the first motor).

The jog speed setting is used whenever the Jog command is active. The jog speed setting range is arbitrarily limited to 10 Hz, to provide safety during manual operation. The acceleration to the jog frequency is instantaneous, but you can choose from three modes for the best method for stopping the jog operation.