National Instruments AT-MIO-16X - Manual (Page 174)

Chapter 5 Programming
© National Instruments Corporation 5-5 AT-MIO-16X User Manual
Programming the Analog Input Circuitry
The analog input circuitry can be programmed for a number of different
modes depending on the application. If single channels are to be
monitored on an ad hoc basis, then the single conversion mode can be
used. If a number of consecutive conversions on any one given channel
are required, the single channel data acquisition mode should be used.
If more than one channel needs to be monitored with multiple
conversions per channel, the scanning data acquisition mode should be
used. This mode scans through a programmed number of channels, each
having its own gain, mode, and range setting. The channels are scanned
in a round-robin fashion, separated in time by the programmed sample
interval. The final mode is the interval-scanning mode. This mode
should be used if more than one channel needs to be monitored, but not
scanned at full speed. Interval scanning sequences through the scan list
with each channel conversion separated in time by the programmed
sample interval, then waits a scan interval before rescanning the list of
channels. The programming of each of these acquisition modes is
described in the following sections.
Single Conversions Using the SCONVERT or
EXTCONV* Signal
Programming the analog input circuitry to obtain a single A/D
conversion involves the following sequence of steps listed in
Figure 5-2.