National Instruments AT-MIO-64F-5, User Manual

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Chapter 2 Configuration and Installation
© National Instruments Corporation 2-29 AT-MIO-64F-5 User Manual
Digital output specifications (referenced to DIG GND):
V
OH
output logic high voltage 2.4 V minimum
V
OL
output logic low voltage 0.5 V maximum
I
OH
output source current, logic high 2.6 mA maximum
I
OL
output sink current, logic low 24 mA maximum
With these specifications, each digital output line can drive 11 standard TTL loads and over 50
LS TTL loads.
Figure 2-12 depicts signal connections for three typical digital I/O applications.
LED
+5 V
TTL Signal
+5 V
Port A
ADIO<3..0>
Port B
BDIO<3..0>
31
29
27
25
32
30
28
26
24
DIG GND
Switch
MIO Subconnector
AT-MIO-64F-5 Board
Figure 2-12. Digital I/O Connections
In Figure 2-12, port A is configured for digital output, and 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 2-12. Digital output applications include sending TTL signals
and driving external devices such as the LED shown in Figure 2-12.