Chapter4 ConnectingSignals
©NationalInstruments Corporation 4-23 NI6013/6014 User Manual
Figures 4-13 and 4-14 show the input and output timing requirements
for TRIG1.
Figure4-13. TRIG1Input Signal Timing
Figure4-14. TRIG1Output Signal Timing
The devicealso uses TRIG1 to ini tiate pretriggered DAQoperations.
In most pretriggered applications, TRIG1 is generated by a software
trigger.Refer to the TRIG2 signal description for a complete description
oft heu se of TRIG1 and TRIG2 in a pretriggered DAQoperation.
TRIG2 Signal
Any PFIpin can externally input the TRIG2 signal, which is available as
anoutput on the PFI1/TRIG2 pin. RefertoFigure 4-12for the relationship
ofTRIG2 to the D AQ sequence.
As ani nput, TRIG2 is configuredin the edge-detection m ode. Youcan
select anyPFI pin as the so urce for TRIG2 and configure the polarity
selection for either rising or falling edge. The selected edge of TRIG2
initiates the posttriggered phase of a pretriggered DAQsequence. In
pretriggeredmode, the TRIG1 signal initiates the data acquisition. The scan
counter(SC) indicates the minimum number of scans before TRIG2 can be
recognized.After the SC decrements to zero, it is loaded with the number
ofposttrigg er scans to acquire while the acquisition continues. The device
Rising-Edge
Polarity
Falling-Edge
Polarity
tw=10 ns minimum
tw
tw=50to100ns
tw