Trigger Controls

The edge triggering mechanism is looking for the signal to cross the trigger level. For a positive edge trigger, the signal must go from below the trigger level, to above the trigger level.

Figure 1. Positive Edge Trigger

1. No trigger – the line must cross.
2. No trigger – wrong direction.
3. Trigger point.

Figure 2. Negative Edge Trigger

1. No trigger – the line must cross.
2. No trigger – wrong direction.
3. Trigger point.

The trigger mechanism has two edge trigger modes: Positive and Negative Edge Trigger.

• To set the Positive Edge Trigger mode, click the button. The button will be highlighted when activated.
• To set the Negative Edge Trigger mode, click the button. The button will be highlighted when activated.

The trigger level can be adjusted in three different ways:

• Enter a trigger level value into the text box. Press the TAB keyboard button or click the mouse outside the text box to let the new value take effect.

• Click on the up/down arrows located to the right of the text box

• With the mouse cursor positioned over the text box, scroll the mouse wheel to increase/decrease the trigger level setting

• Drag the trigger level line in the plot area to a new position

The Oscilloscope trigger sub-module uses one of the channel signals when looking for the trigger condition.

• Click the colored Trigger source button corresponding to the channel chosen for use as a trigger source. The active Trigger source button will be highlighted.