Mitsubishi Electronics QD75D, QD75P user manual Vs =, Mm/pulse, Pulse/s

1 PRODUCT OUTLINE

MELSEC-Q

(a)In the system shown in Fig. 1.4, the movement amount per pulse, command pulse frequency, and the deviation counter droop pulser amount are determined as follows:

1)Movement amount per pulse

The movement amount per pulse is determined by the worm gear lead, deceleration ratio, and the pulse encoder resolution.

The movement amount, therefore, is given as follows: (Number of pulses output) × (Movement amount per pulse).

A =	L		[mm/pulse]
	R ⋅	n

2) Command pulse frequency

The command pulse frequency is determined by the speed of the moving part and movement amount per pulse:

Vs =	V	[pulse/s]
	A

3)Deviation counter droop pulser amount.

The deviation counter droop pulser amount is determined by the command pulse frequency and position loop gain.

ε =	Vs	[pulse]
	K

(b)The QD75 allows the user to select from the following four units as the unit used by positioning commands to any of the axes (1 to 4, if the module supports four axes): mm, inch, degree, and pulse.

The unit selected for one axis may differ from the unit selected for another axis.

When such data as the movement amount per pulse, acceleration/deceleration time, positioning speed, and positioning address are correctly set in consideration of the chosen unit, the QD75 can calculate the number of pulses required for a movement amount to the target positioning address and execute the positioning by outputting a pulse train that includes the calculated number of pulses.

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