DAQ system PCIe-FRM24 C User Manual page 14

A rotary encoder is used to detect the rotational direction and speed of a rotating object such
as an electronic volume or motor. When the rotating shaft is turned, two pulse signals that can
discriminate left and right come out in proportion to the speed. It is divided into single phase,
A/B phase and A/B/Z phase, and the resolution is determined according to the number of pulses
indicating how many A/Bs are generated in one rotation.
Encoder
Motion Controller
Or
Digital I/O
A, B phase : Forward movement
A Phase
B Phase
[Figure 2-11. Encoder A/B Phase Clockwise/Counter Clockwise]
A and B operates the difference of 90 degree as shown in the figure above.
When "B" is low and "A" is high, it move counter-wise direction
When "B" is high and "A" is high, it move count counter-wise direction.
Z also used as a trigger because Z shows the one on the wheel once.
PCIe-FRM24_C
Encoder IN
Line Driver
FPGA Core Logic
PHOTO
[Figure 2-12. Encoder Z Phase (Phase)]
PCIE-FRM24_C User's Manual
OUT
TTL(3.3V)
Line Drive
A, B phase : Backward movement
A Phase
B Phase
Camera
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