Positive or negative edge trigger

Edge Trigger mode corresponds to the commonly used trigger facility found on oscilloscopes.

The analogue trigger input is continuously sampled at the selected sample rate. If the programmed trigger level is crossed by the trigger signal from lower to higher values (rising edge)... Edge trigger. Diagram showing positive edge point in relation to a analogue input signal.
...or higher to lower value (falling edge), then the trigger event will be detected at the programmed level. The card will start recording or replaying data depending on functionality, (digitiser or waveform generator).

N.B. Positive and negative triggers can be combined!
Edge trigger. Diagram showing negative edge point in relation to a analogue input signal.
A digital trigger input is also available on the cards faceplate, located alongside the multiple purpose digital (LVTTL) I/O connections. The edge trigger operation can be used with this input too, however the level is not programmed, instead it works by simply looking for a fast edge. User sets this to be either positive or negative edge recognition, or combined as shown opposite.

N.B. AND/OR combinations are possible between the analogue and digital triggers.
Edge trigger. 
		Diagrams showing edge points in relation to a digital TTL input signal.

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