National Instruments PCI-6034E, Руководство пользователя

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Chapter 10 Triggering
© National Instruments Corporation 10-5 E Series User Manual
Level Triggering with Hysteresis
Hysteresis adds a programmable window above or below the trigger level
that a valid trigger signal must pass through and is often used to reduce
false triggering due to noise or jitter in the signal.
When using Hysteresis with a rising slope, the trigger asserts when the
signal starts below Level and then crosses above Level . The trigger
deasserts when the signal crosses below Level minus hysteresis as shown
in Figure 10-5.
Figure 10-5. High Hysteresis
When using Hysteresis with a falling slope, the trigger asserts when the
signal starts above Level and then crosses below Level . The trigger
deasserts when the signal crosses above Level plus hysteresis, as shown in
Figure 10-6.
Figure 10-6. Low Hysteresis
Window Triggering
A window trigger occurs when an analog signal either passes into (enters)
or passes out of (leaves) a window defined by two voltage levels. Specify
the levels by setting the window
Top value and the window Bottom value.
Level
Analog Comparison Event
Hysteresis
Level
Analog Comparison Event
Hysteresis