National Instruments E Series , Analog Input

Chapter 3 Hardware Overview
DAQCard E Series User Manual 3-2  National Instruments Corporation
Figure 3-2 shows a block diagram for the DAQCard-AI-16XE-50.
Analog Input
The analog input section of each DAQCard is software configurable.
You can select different analog input configurations through
application software designed to control the DAQCards. The following
sections describe in detail each of the analog input categories.
Input Mode
The DAQCards have three different input modes—nonreferenced
single-ended (NRSE) input, referenced single-ended (RSE) input, and
differential (DIFF) input. The single-ended input configurations use up
to 16 channels. The DIFF input configuration uses up to eight channels.
Input modes are programmed on a per channel basis for multimode
scanning. For example, you can configure the circuitry to scan 12
channels—four differentially configured channels and eight
Figure 3-2. DAQCard-AI-16XE-50 Block Diagram
Timing
PFI / Trigger
I/O Connector
32
PCMCIA Connector
Digital I/O (8)
16-Bit
Sampling
A/D
Converter
Configuration
Memory
+
Programmable
Gain
Amplifier
–
Calibration
Mux
Mux Mode
Selection
Switches
Analog
Muxes
Voltage
REF Calibration
DACs
DAQ - STC
Analog Input
Timing/Control
Analog Output
Timing/Control
Digital I/O
Trigger
Counter/
Timing I/O
RTSI Bus
Interface
DMA/
Interrupt
Request
Bus
Interface
(8)
(8)
AI Control
Data (16)
Analog
Input
Control
EEPROM
Control DMA Interface
DAQ-PCMCIA
DAQ-STC
Bus
Interface
Analog
Output
Control
Bus
Interface
IRQ
DMA
Data
Transceivers
ADC
FIFO
EEPROM