Using Digital Inputs And Outputs - National Instruments NI 4350 User Manual

Using Digital Inputs and Outputs

Connecting Your Digital Input and Output
© National Instruments Corporation
The NI 4350 features TTL-compatible digital lines. These lines can be
individually configured either as inputs or as outputs. At power-up,
these digital lines are configured as high-impedance inputs with a weak
pull-up.
You can use the DIO lines as an interface to control processes, control
events such as turning on and off heaters, relays, motors, or lights,
generate patterns for testing, and communicate with peripheral
equipment. If the current and voltage specifications of the DIO lines are
not appropriate for your requirements, you can use external signal
conditioning such as electromechanical relay, solid-state relay,
opto-coupler, and so on.
You can use the digital input lines to trigger analog acquisitions. To do
this with the LabVIEW or NI435X instrument driver, set up the analog
acquisition configuration, then poll the digital input line for your trigger
condition and, upon getting the trigger, start the analog acquisition.
All NI 4350 accessories are designed to be used for DIO. Refer to your
accessory installation guide for instructions on how to connect your
DIO lines. Figure 3-11 shows examples of how to connect DIO
for various applications such as controlling an LED, monitoring a
TTL-compatible or CMOS compatible signal, monitoring a low-voltage
switch, and monitoring a low-voltage transistor.
3-27
Chapter 3 NI 4350 Operation
NI 4350 User Manual