MAN0878-09-EN_XLE_XLT_UserManual
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12.2.4 Quadrature
Two HSC inputs are consumed for each of the two possible Quadrature counters. For example,
selecting quadrature mode for HSC 1 will use HSC inputs 1 and 2, which correspond to A and B
quadrature signals. Therefore, HSC 1 and 3 may be configured for quadrature input.
Alternately, HSC 3 may be configured to reset HSC1 (quadrature) count on a marker input
Quadrature mode works much like the totalizer except the accumulator will automatically
increment or decrement based on the rotation phase of the two inputs. See the following
example for more details. Quadrature inputs are typically used for reporting the value of an
encoder.
Two modes are available for quadrature that select whether the accumulator counts up or
down when the phase of input 1 leads input 2. Check your encoder’s documentation to
determine the output form it uses or try both modes to determine if the encoder counts up
when expected.
Using the above waveforms and a HSC input configuration of “Quadrature”
-
“1 leads 2, count
up,” the accumulator will count up when 1 is rising and 2 is low, 1 is high and 2 is rising, 1 is
falling and 2 is high, and when 1 is low and 2 is falling. This results in 4 counts per revolution.
In order to determine the number of cycles, the accumulator would have to be divided by 4.
90°
Phase shift
1
(leading)
2
(lagging)
