National Instruments VXI-MIO Series - Manual (Page 77)

Chapter 4 Signal Connections
 National Instruments Corporation 4-31 VXI-MIO Series User Manual
Figure 4-20. STARTSCAN Output Signal Timing
The CONVERT* pulses are masked off until the module generates the
STARTSCAN signal. If you are using internally generated conversions,
the first CONVERT* will appear when the onboard sample interval
counter reaches zero. If you select an external CONVERT*, the first
external pulse after STARTSCAN will generate a conversion. Separate
the STARTSCAN pulses by at least one scan period.
A counter on your VXI-MIO Series module internally generates the
STARTSCAN signal 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 data acquisition sequence.
Scans occurring within a data acquisition sequence may be gated by
either the hardware (AIGATE) signal or software command register
gate.
t
w
= 50-100 ns
a. Start of Scan
t
off
t
off
= 10 ns minimum
Start Pulse
CONVERT*
STARTSCAN
STARTSCAN
b. Scan in Progress, Two Conversions per Scan
t
w