ADLINK PCI-9810 - Manual (Page 41)

Operation Theory 29
5 Operation Theory
The operation theorem of the PCI-9812/9810 card functions is
described in this chapter. These functions include A/D conversion
and digital input. This section aims to assist you in understanding,
operating, and programming the PCI-9812/9810.
5.1 Conversion Procedure
Before programming the PCI-9812/9810 to perform A/D
conversions, you must first understand the following concepts:
X A/D signal source control
When using an A/D converter, you must be familiar with the
properties of the signal to be measured, and you must decide
which channels to use and connect the signals to the PCI-
9812/9810 card. In addition, you must define and control the A/
D signal sources, including the A/D channels, A/D gains, and
A/D signal types. Refer to section 5.2 for A/D signal source
control.
X A/D trigger source control
After identifying the A/D signal source, you must decide how to
trigger the A/D conversion and define or control the trigger
source. The A/D converter will start to convert the signal to a
digital value when a trigger condition is met. Refer to section
5.3.
X A/D clock control
The A/D clock is controlled by an internal or external clock
source. The operation of the A/D clock source is described in
section 5.4.