Chapter 4
Connecting Signals
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National Instruments Corporation
4-33
Figure 4-14.
Typical Pretriggered Acquisition
TRIG1 Signal
Any PFI pin can externally input the TRIG1 signal, which is available as
an output on the PFI0/TRIG1 pin.
Refer to Figures 4-13 and 4-14 for the relationship of TRIG1 to the DAQ
sequence.
As an input, the TRIG1 signal is configured in the edge-detection mode.
You can select any PFI pin as the source for TRIG1 and configure the
polarity selection for either rising or falling edge. The selected edge of
the TRIG1 signal starts the DAQ sequence for both posttriggered and
pretriggered acquisitions. The AT-MIO-16E-1, AT-MIO-16E-2,
AT-MIO-16XE-10, AT-AI-16XE-10, and AT-MIO-64E-3 support analog
triggering on the PFI0/TRIG1 pin. Refer to Chapter 3,
, for more information on analog triggering.
As an output, the TRIG1 signal reflects the action that initiates a DAQ
sequence, even if the acquisition is being externally triggered by another
PFI. The output is an active high pulse with a pulse width of 50 to 100 ns.
This output is set to high-impedance at startup.
Don't Care
0
1
2
3
1
0
2
2
2
TRIG1
TRIG2
STARTSCAN
CONVERT*
Scan Counter