Chapter 5
Theory of Operation and Register-Level Programming
5-2
©
National Instruments Corporation
Figure 5-1.
AMUX-64T Block Diagram
The AMUX-64T multiplexers are controlled by a 4-bit scanning counter
that is loaded via the 4-bit digital I/O port A of the MIO board. The MIO
signal EXTSTROBE* loads the value at digital I/O port A into the
AMUX-64T scanning counter. The MIO signal SCANCLK, which is active
during scanned data acquisition, switches the input channels automatically
on the AMUX-64T after each A/D conversion.
CH0
CH1
CH2
CH3
Jumper W1
IC Temperature Sensor
CH60
CH61
CH62
CH63
Multiplexers
64 Analog Inputs
50-Pin I/O Connector
16 Analog Inputs
50-Pin I/O Connector
Scanning
Counter
DIP Switch
4
DIOA
<3..0>
2
Timing
Lines
MUX Address
and Enables
To
MIO board
To Second
AMUX-64T
(Optional)
Power
Converter
External
+5 V
Switch
+5 V
LED
+5 V
+15 V
-15 V
Signal
Conditioning
Area
•
•
•
•
•
•
•
•
•
•
•
•
•
•
68-Pin I/O Connector