ADLINK USB-1903 - Manual (Page 56)

42 Operation
4.3.2 External Analog Triggering
The analog multiplexer can select one input channel as the analog
trigger source. That is, one of 16 input channels in single-end
mode (or 8 input channels in pseudo-differential mode) can be
selected as the analog trigger source. An external analog trigger
occurs when the analog trigger signal crosses above (above high)
or below (below low) the pre-defined voltage level. The range of
trigger level is the full-scale range of the selected input channel
and the resolution is 16-bit. In external analog trigger mode, the
first acquired data starts with a delay of 4 microseconds.
Below-Low Analog Triggering
In below-low analog triggering, as shown, the trigger signal is
generated when the input analog signal is less than the
Low_Threshold voltage. High_Threshold setting is not used in
this triggering situation.
Figure 4-4: Below-Low Analog Triggering
Above-High Analog Triggering
In above-high analog triggering, as shown, the trigger signal is
generated when the input analog signal exceeds the
High_Threshold voltage. Low_Threshold setting is not used in
this triggering situation