National Instruments NI 784xR - Manual (Page 40)

Chapter 2 Hardware Overview of the NI 78xxR
© National Instruments Corporation 2-19 R Series Intelligent DAQ User Manual
Figure 2-11. Example Digital I/O Connections
Figure 2-11 shows DIO<0..3> configured for digital input and DIO<4..7>
configured for digital output. Digital input applications include receiving
TTL, LVTTL, CMOS, or LVCMOS signals and sensing external device
states, such as the state of the switch shown in Figure 2-11. Digital output
applications include sending TTL or LVCMOS signals and driving external
devices, such as the LED shown in Figure 2-11.
The NI 78xxR SHC68-68-RDIO cable contains individually shielded
bundles that route each digital signal on an individually shielded pair of
wires, and each signal is twisted with its own wire to digital ground.
The SHC68-68-RDIO was designed specifically for R Series devices and is
the NI-recommended cable for digital applications. If you are using the
SH68-C68-S cable, however, please note the following considerations.
*3.3 V CMOS
†
Use a pull-up resistor when driving 5 V CMOS devices.
LED
TTL, LVTTL, CMOS, or LVCMOS Signal
+5 V
Switch
I/O Connector
DGND
NI 783 x R/784 x R/785 x R
DIO<0..3>
DIO<4..7>
+5 V
5 V CMOS
†
TTL or
LVCMOS*
Compatible
Devices
DGND