Figure 4-18. startscan output signal timing – National Instruments NI 6014 User Manual
Page 52
Chapter 4
Connecting Signals
4-26
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Figure 4-18. STARTSCAN Output Signal Timing
The CONVERT* pulses are masked off until the device generates the
STARTSCAN signal. If you are using internally generated conversions,
the first CONVERT* appears when the onboard sample interval counter
(SI2) reaches zero. If you select an external CONVERT*, the first external
pulse after STARTSCAN generates a conversion. The STARTSCAN pulses
should be separated by at least one scan period.
A counter on the NI 6013/6014 internally generates STARTSCAN unless
you select some external source. This counter is started by the TRIG1
signal and is stopped either by software or by the sample counter.
Scans generated by either an internal or external STARTSCAN signal are
inhibited unless they occur within a DAQ sequence. Scans occurring within
a DAQ sequence may be gated by either the hardware (AIGATE) signal or
software command register gate.
STARTSCAN
a. Start of Scan
t
w
= 50 to 100 ns
t
w
Start Pulse
CONVERT*
STARTSCAN
b. Scan in Progress, Two Conversions per Scan
t
off
= 10 ns minimum
t
off