Figure 4-2. high pulse with rising edge trigger, Figure 4-3. high and low pulse trains, Quadrature encoder – National Instruments NI 1450 Series User Manual

Page 51: Quadrature encoder -6

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Chapter 4

Digital I/O Functionality

NI 1450 Series Compact Vision System User Manual

4-6

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Figure 4-2. High Pulse with Rising Edge Trigger

Figure 4-3 shows how to create a high and low pulse train with a
microsecond delay and width.

Figure 4-3. High and Low Pulse Trains

Quadrature Encoder

The quadrature encoder uses ISO Input 6 for its Phase A input and
ISO Input 7 for its Phase B input. Encoder speed is limited by the speed of
the isolated inputs. Each isolated input can change at a maximum rate of
100 kHz, making the maximum encoder rate 400,000 counts/s.

The quadrature encoder can also be used as a timebase for the pulse
generation delay.

Trigger

Pulse

Delay

Width

Low Pulse Train

High Pulse Train

Delay

Width

Width

Delay

Software

Start

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