Analog Edge Trigger With Hysteresis (Rising Slope); Analog Edge Trigger With Hysteresis (Falling Slope) - National Instruments NI 6221 User Manual

Hysteresis
Analog Comparison Event
© National Instruments Corporation

Analog Edge Trigger with Hysteresis (Rising Slope)

When using hysteresis with a rising slope, you specify a trigger level and
amount of hysteresis. The high threshold is the trigger level; the low
threshold is the trigger level minus the hysteresis.
For the trigger to assert, the signal must first be below the low threshold,
then go above the high threshold. The trigger stays asserted until the signal
returns below the low threshold. The output of the trigger detection
circuitry is the internal Analog Comparison Event signal, as shown in
Figure 11-5.
First signal must go
below low threshold
Figure 11-5. Analog Edge Triggering with Hysteresis Rising Slope Example

Analog Edge Trigger with Hysteresis (Falling Slope)

When using hysteresis with a falling slope, you specify a trigger level and
amount of hysteresis. The low threshold is the trigger level; the high
threshold is the trigger level plus the hysteresis.
For the trigger to assert, the signal must first be above the high threshold,
then go below the low threshold. The trigger stays asserted until the signal
returns above the high threshold. The output of the trigger detection
circuitry is the internal Analog Comparison Event signal, as shown in
Figure 11-6.
Then signal must
go above high threshold before
Analog Comparison Event asserts
11-5
Chapter 11 Triggering
High threshold
(Level)
Low threshold
(Level – Hysteresis)
M Series User Manual