National Instruments E Series - Manual (Page 31)

Chapter 3 Hardware Overview
 National Instruments Corporation 3-9 DAQCard E Series User Manual
Analog Trigger
♦
DAQCard-AI-16E-4
In addition to supporting internal software triggering and external
digital triggering to initiate a data acquisition sequence, the
DAQCard-AI-16E-4 also supports analog triggering. You can
configure the analog trigger circuitry to accept either a direct
analog input from the PFI0/TRIG1 pin on the I/O connector or a
postgain signal from the output of the PGIA, as shown in
Figure 3-4. The trigger-level range for the direct analog channel is
±
10 V in 78 mV steps. The range for the post-PGIA trigger
selection is simply the full-scale range of the selected channel, and
the resolution is that range divided by 256.
There are five analog triggering modes available, as shown in
Figures 3-5 through 3-9. You can set
lowValue and highValue
independently in software.
Figure 3-4. Analog Trigger Block Diagram
Analog
Input
Channels
PFI0/TRIG1
PGIA
+
-
ADC
DAQ-STC
Analog
Trigger
Circuit
Mux