Analog Input - DAQ DAQCard-1200 User Manual

Analog Input

© National Instruments Corporation
Each 82C53 contains three independent 16-bit counter/timers and one 8-bit
Mode Register. Each counter has a CLK input pin, a GATE input pin, and
an OUT output pin. You can program all three counter/timers to operate in
several useful timing modes.
The first group of counter/timers is called Group A and includes A0, A1,
and A2. You can use these three counters for internal DAQ and DAC
timing, or you can instead use the three external timing signals,
EXTCONV*, EXTTRIG and EXTUPDATE*, for DAQ and DAC timing.
The second group of counter/timers is called Group B and includes B0, B1,
and B2. You can use counters B0 and B1 for internal DAQ and DAC timing,
or you can use the external timing signal CLKB1 for AI timing. If you are
not using Counters B0 and B1 for internal timing, you can use these
counters as general purpose counter/timers. Counter B2 is reserved for
external use as a general purpose counter/timer.
For a more detailed description of Counter Group A and Counters B0
and B1, refer to the following Analog Input and
The DAQCard-1200 has eight AI channels with software-programmable
gain and 12-bit A/D conversion. The DAQCard-1200 also contains DAQ
timing circuitry for automatic timing of multiple A/D conversions and
includes advanced options such as external triggering, gating, and clocking.
Figure 4-4 shows a block diagram of the AI circuitry.
4-5
Chapter 4 Theory of Operation
Analog Output sections.
DAQCard-1200 User Manual