Tristate Mode with DAQPad-6507

[Anthony_Wong]

Hi, I'm currently using LabVIEW 7.1 and a USB DAQPad-6507

I recently posted over at the Digital I/O forums, and realize that the 6507 does not support tristate mode directly. However, I plan to include relays that will mimic the tristate mode.

I'm wondering if it is possible to create a program in LabVIEW that will allow the control of the artificial tristate mode I plan to create.

i.e. Have two lines from the board to control the device (that is desired to have a tristate capability). In LabVIEW, the VI will have two switches, if both are off, (i.e. 0 0) then the device is open. If the mode is (0 1), then it is ground. If the mode is (1 0), then it is high voltage. (1 1) is not required, as it will short circuit the device.

Is this a simple task (or even possible?) in LabVIEW? Any ideas or comments are greatly appreciated

[Travis G.]

Hello Anthony,

Reading and writing to digital lines with your device in LabVIEW can be easily accomplished using the Traditional NI-DAQ Digital I/O functions, located on the functions palette under All Functions > NI Measurements > Data Acquisition > Digital I/O.  There are functions to read and write to digital lines or ports on your device.  I would recommend taking a look at some of the Traditional NI-DAQ shipping examples, found within LabVIEW under Help > Find Examples.  To find examples showing how to use the Traditional NI-DAQ Digital I/O functions, browse by category to Hardware Input and Output > Traditional DAQ > Digital Input and Output > 8255. 

I hope this helps,

Travis G.
Applications Engineering
National Instruments
www.ni.com/support