Generate and Acquire Data on Bidirectional Channels

This example shows how to use a bidirectional channel and read and write data using the same two lines on an NI 6255.

Discover NI devices connected to your system and find the ID for the NI 6255.

d = daqlist("ni")

dev = 3×4 table DeviceID Description Model DeviceInfo ________ ___________________________________ __________ _______________________ "Dev1" "National Instruments(TM) USB-6255" "USB-6255" [1×1 daq.ni.DeviceInfo] "Dev2" "National Instruments(TM) USB-6363" "USB-6363" [1×1 daq.ni.DeviceInfo]

Create a DataAcquisition and add two lines from port 0 and 2 lines from port 1 on Dev1.

d = daq("ni"); addbidirectional(d,"Dev1","Port0/Line0:1","Digital"); addbidirectional(d,"Dev1","Port1/Line0:1","Digital"); d.Channels

ans = Index Type Device Channel Measurement Type Range Name _____ _____ ______ _____________ _______________________ _____ __________________ 1 "dio" "Dev1" "port0/line0" "Bidirectional (Input)" "n/a" "Dev1_port0/line0" 2 "dio" "Dev1" "port0/line1" "Bidirectional (Input)" "n/a" "Dev1_port0/line1" 3 "dio" "Dev1" "port1/line0" "Bidirectional (Input)" "n/a" "Dev1_port1/line0" 4 "dio" "Dev1" "port1/line1" "Bidirectional (Input)" "n/a" "Dev1_port1/line1"

Set the direction on all channels to output data.

set(d.Channels,"Direction","Output");

Generate the digital output data.

写(d [1 0 1 0])

Change the direction on all channels to input data

set(d.Channels,"Direction","Input");

Acquire the digital data.

read(d,"OutputFormat","Matrix")

ans = 1 0 1 0