ADLINK PXI-2022 - Manual (Page 34)

26 Function Block and Operation Theory
Figure 4-3: Basic Acquisition Timing of PXI-2020/2022
4.2.3 AI Data Format
When using an A/D converter, users should first know about the
properties of the signal to be measured. Users can decide which
channel to use and how to connect the signals to the card. Please
refer to 4.2 for signal con-nections.
The A/D acquisition is initiated by a trigger source; users must
decide how to trigger the A/D conversion. The data acquisition will
start once a trigger condition is matched. After the end of an A/D
conversion, the A/D data is buffered in a Data FIFO. The A/D data
can now be transferred into the PC's memory for further process-
ing.
Two acquisition modes, Software Polling and Scan acquisition are
de-scribed below. Timing, trigger modes, trigger sources, and
transfer me-thods are included in this section. The following table
illustrates the idea transfer characteristics of various input ranges
of the PXI-2020/2022. The data format of the PXI-2020/2022 is
straight binary.