National Instruments AT E Series

Chapter4 ConnectingSignals

©NationalInstruments Corporation 4-35 ATE Series User Manual

before TRIG2 can berecognized. A fter the scan counter decrements to

zero,it is loaded with the number of posttrigger scans to acquire while the

acquisitioncontinue s. The deviceignores the TRIG2 signal if it is asserted

priort o the scancounter decrementing to zero. After the selected edge of

TRIG2 is received,the device acquires a fixed number of scans and the

acquisitionstops. This mode acquires data both beforeand after receiving

TRIG2.

As ano utput, the TRIG2 signal reflects the posttrigger in a pretriggered

acquisition sequence, evenif the acquisitio n isb eing externally triggered

byanother PFI. The TRIG2 signal is not used in posttriggered data

acquisition. The output is an activehigh pulse with a pulse width of

50 to 100 ns. This output is set to high-impedance at startup.

Figures 4-17 and 4-18 showthe input and outp ut timing requirements for

the TRIG2 signal.

Figure4-17. TRIG2 Input Signal Timing

Figure4-18. TRIG2 Output Signal Timing

Rising-Edge

Polarity

Falling-Edge

Polarity

tw=10 ns minimum

tw=50to100ns