User manual

Chapter 4 Connecting Signals
NI 6034E/6035E/6036E User Manual 4-22 ni.com
As an input, you can individually configure each PFI pin for edge or level
detection and for polarity selection, as well. You can use the polarity
selection for any of the 13 timing signals, but the edge or level detection
depends upon the particular timing signal being controlled. The detection
requirements for each timing signal are listed within the section that
discusses that individual signal.
In edge-detection mode, the minimum pulse width required is 10 ns. This
applies for both rising-edge and falling-edge polarity settings. There is no
maximum pulse-width requirement in edge-detect mode.
In level-detection mode, there are no minimum or maximum pulse-width
requirements imposed by the PFIs themselves, but there may be limits
imposed by the particular timing signal being controlled. These
requirements are listed later in this chapter.
DAQ Timing Connections
The DAQ timing signals are SCANCLK, EXTSTROBE*, TRIG1, TRIG2,
STARTSCAN, CONVERT*, AIGATE, and SISOURCE.
Posttriggered data acquisition allows you to view only data that is acquired
after a trigger event is received. A typical posttriggered DAQ sequence is
shown in Figure 4-11. Pretriggered data acquisition allows you to view data
that is acquired before the trigger of interest in addition to data acquired
after the trigger.
Figure 4-11. Typical Posttriggered Acquisition
13042
TRIG1
STARTSCAN
CONVERT*
Scan Counter
UM.book Page 22 Monday, May 14, 2001 10:32 AM