National Instruments E Series - Manual (Page 64)

Chapter 4 Signal Connections
DAQCard E Series User Manual 4-28  National Instruments Corporation
Figures 4-14 and 4-15 show the input and output timing requirements
for the TRIG1 signal.
The DAQCard also uses the TRIG1 signal to initiate pretriggered data
acquisition 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 data acquisition operation.
Figure 4-14. TRIG1 Input Signal Timing
Figure 4-15. TRIG1 Output Signal Timing
Rising-edge
polarity
Falling-edge
polarity
t
w
t
w
= 10 ns minimum
t
w
t
w
= 50-100 ns