National Instruments DAQCard-1200 - Manual (Page 54)

© National Instruments Corporation 4-1 DAQCard-1200 User Manual
4
Theory of Operation
This chapter explains the operation of each functional unit of the
DAQCard-1200.
Functional Overview
The block diagram in Figure 4-1 shows a functional overview of the
DAQCard-1200.
Figure 4-1. DAQCard-1200 Block Diagram
I/O Connector
+12 V
–12 V
+5 V
PCMCIA
I/O
Channel
Interface
Decode
Circuitry,
Core
Logic
PCMCIA
I/O Channel
4
4
8
8
8
1
1
8
8
8
8
3
Interrupt
Interface
82C53
Ctr/Timer
Group A
82C55A
Digital
Interface
DC-DC
Converter
20 MHz
Oscillator
Time
Divider
2K
FIFO
12-Bit
A/D
Pgm
Gain
Dither
Input
Mux
Control
Signals
82C53
Ctr/Timer
Group B
12-Bit
D/A
12-Bit
D/A
Calibration
1MHz
Timebase
2 MHz
Timebase
data