Table Of Contents

Trigger Settings (Oscilloscope)

Last Modified: December 14, 2018

You can configure the trigger by using the trigger settings.

You can configure some settings directly on the panel. To access additional settings, click the configuration button on the top right side of the section.

Setting Description
Mode Mode in which the Oscilloscope responds to a trigger.
  • Auto—The Oscilloscope waits momentarily for any occurrence of trigger condition before automatically triggering.
  • Normal—The Oscilloscope waits indefinitely for any occurrence of trigger condition.
Type Type of trigger to start the acquisition. Refer to the Oscilloscope Concepts section to learn about different trigger types.
  • Immediate—There is no external signal that triggers the acquisition, and the acquisition begins immediately.
  • Analog edge—A trigger occurs when the signal you select in Source crosses the trigger threshold that you define in Level.
  • Digital edge—A trigger occurs on a rising edge of an external digital signal. To use a digital edge trigger, you must first connect a TTL-level signal to the Trigger channel on the NI ELVIS III.
Source Source of the trigger that starts the data acquisition.
  • Channel N—The instrument uses Channel N as the trigger signal. You can select Channel N only when Type is Analog edge.
  • TRIG—The instrument uses the Trigger channel on the NI ELVIS III as the trigger signal. You can select TRIG only when Type is Digital edge.
Level Voltage at which a trigger occurs. This setting is enabled only when Type is Analog edge. Level must be between -25 V + Vertical offset and 25 V + Vertical offset. For example, if Vertical offset is 25 V, Level must be between 0 V and 50 V.

The Oscilloscope uses hysteresis to reduce false triggering due to noise or jitter in the signal, by adding a window above or below Level. The hysteresis is 25% of Volts per division. You can adjust the value of hysteresis by configuring Volts per division in Channel Settings. Refer to Hysteresis to learn more about how hysteresis works.

Slope Place at which a trigger occurs.
  • Rising—The trigger occurs at a rising edge for digital signals, or a rising slope for analog signals.
  • Falling—The trigger occurs at a falling edge for digital signals, or a falling slope for analog signals.
  • Either—The trigger occurs in either case.
Acquisition delay Decides whether the instrument waits for a certain period of time after a trigger is detected before it starts sampling. Enable Acquisition delay when there is a delay between when the trigger occurs and when the desired data is generated, or when you need a high sampling rate for the desired acquisition window.

The time between the trigger position and the middle of the display pane. The value of Position changes when you move the trigger horizontally.

The following settings are available on the panel only:

Setting Description
Force Manually triggers the Oscilloscope.
Set 50% Sets the trigger level as 50% of the peak-to-peak voltage of the measured signal. This setting is available only when Type is Analog edge.

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