BitFlow NEO-PCE-CLB, Справочник по аппаратуре

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Understanding Stage Movement vs. Quadrature Encoder Modes The Neon
NEO-4-4 BitFlow, Inc. Version G.5
4.2 Understanding Stage Movement vs. Quadrature Encoder Modes
The quadrature encoder system has many modes that can be used in various combi-
nations. These combinations are easier to understand through a few simple illustra-
tions. Figure 4-1 shows the basic Encoder Count vs. Time graph and how it
corresponds to stage movement. Keep in mind that the encoder could be attached to
any mechanical system, however, a back and forth stage is a simple way to illustrate
these modes.
In Figure 4-1 you can see as the stage moves back and forth, the encoder counts up
and down. Further, in this example we assume QENC_AQ_DIR = 1, which tells the sys-
tem to only acquire when the encoder counter is moving in the positive direction. This
is illustrated by solid lines in the positive direction and dashed lines in the negative
direction.
Figure 4-1 Encoder Count vs Time
Time
Encoder
Co
u nter
These lines are acq u ired
These lines are not acq u ried
Corresponding Encoder Co u nt vs. Time
Stage Movement
Stage
Direction
of Motion