National Instruments PCI-DIO-96 - page 27

Chapter 3 Signal Connections
© National Instruments Corporation 3-7 PCI-DIO-96 User Manual
Figure 3-3 depicts signal connections for three typical digital I/O
applications.
Figure 3-3. Digital I/O Connections Block Diagram
In Figure 3-3, PPI A, port A, is configured for digital output, and PPI C,
port B, is configured for digital input. Digital input applications include
receiving TTL signals and sensing external device states such as the
state of the switch in Figure 3-3. Digital output applications include
sending TTL signals and driving external devices such as the LED
shown in Figure 3-3.
41
43
45
47
67
69
71
73
50, 100
GND
PCI-DIO-96 Board
Switch
I/O Connector
+5 V
+5 V
LED
PPI C
Port B

CPB<7..4>
PPI A
Port A

APA<3..0>
TTL Signal