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Chapter 4
Connecting Signals
4-34
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Figure 4-15. TRIG1 Input Signal Timing
Figure 4-16. TRIG1 Output Signal Timing
The device also uses the TRIG1 signal to initiate pretriggered DAQ
operations. In most pretriggered applications, the TRIG1 signal is
generated by a software trigger. Refer to the TRIG2 signal description for
a complete description of the use of TRIG1 and TRIG2 in a pretriggered
DAQ operation.
operations. In most pretriggered applications, the TRIG1 signal is
generated by a software trigger. Refer to the TRIG2 signal description for
a complete description of the use of TRIG1 and TRIG2 in a pretriggered
DAQ operation.
TRIG2 Signal
Any PFI pin can externally input the TRIG2 signal, which is available as
an output on the PFI1/TRIG2 pin.
an output on the PFI1/TRIG2 pin.
Refer to Figure 4-13 for the relationship of TRIG2 to the DAQ sequence.
As an input, the TRIG2 signal is configured in the edge-detection mode.
You can select any PFI pin as the source for TRIG2 and configure the
polarity selection for either rising or falling edge. The selected edge of the
TRIG2 signal initiates the posttriggered phase of a pretriggered acquisition
sequence. In pretriggered mode, the TRIG1 signal initiates the data
acquisition. The scan counter indicates the minimum number of scans
You can select any PFI pin as the source for TRIG2 and configure the
polarity selection for either rising or falling edge. The selected edge of the
TRIG2 signal initiates the posttriggered phase of a pretriggered acquisition
sequence. In pretriggered mode, the TRIG1 signal initiates the data
acquisition. The scan counter indicates the minimum number of scans
Rising-Edge
Polarity
Falling-Edge
Polarity
t
w
= 10 ns minimum
t
w
t
w
= 50 to 100 ns
t
w