National Instruments NI 6013 User Manual

Also see for NI 6013: Note to Users

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National Instruments NI 6013 User Manual Manual pdf 54 page image

Chapter 4 Connecting SignalsNI 6013/6014 User Manual 4-28 ni.comFigure 4-20. CONVERT* Output Signal TimingThe SI2 counter on the NI 6013/6014 normally generates CONVERT*unless you select some external source. The counter is started by theSTARTSCAN signal and continues to count down and reload itself untilthe scan is finished. It then reloads itself in preparation for the nextSTARTSCAN pulse.A/D conversions generated by either an internal or external CONVERT*signal are inhibited unless they occur within a DAQ sequence. Scansoccurring within a DAQ sequence may be gated by either the hardware(AIGATE) signal or software command register gate.AIGATE SignalAny PFI pin can externally input the AIGATE signal, which is notavailable as an output on the I/O connector. AIGATE can mask off scansin a DAQ sequence. You can configure the PFI pin you select as the sourcefor AIGATE in level-detection mode. You can configure the polarityselection for the PFI pin for either active high or active low. Inlevel-detection mode if AIGATE is active, the STARTSCAN signal ismasked off and no scans can occur.AIGATE can neither stop a scan in progress nor continue a previouslygated-off scan; in other words, once a scan has started, AIGATE does notgate off conversions until the beginning of the next scan and, conversely,if conversions are being gated off, AIGATE does not gate them back onuntil the beginning of the next scan.tw = 50 to 150 nstw