Generating a manually on/off continuous DC Voltage

[HMayer]

I have no experience using digital input/output with labview so would like to know if the following is possible.
I am interested in controlling a microsolenoid valve using labview. It operates off 5 Vdc, and for now I would like
to manually (and in the future automated it) turn the valve on and off using a labview VI. I basically need an
on/off switch which then supplies a port in the breakout box with 5Vdc that I can wire up to the valve.

Has anyone done this before or have some sample code? If not, what would be the best resource to learn.

Thanks for your time.

[Buechsenschuetz]

I can't help you with any code, but if you need to drive a relay or solenoid first you should check whether you fulfill all hardware requirements. Most solenoids need more current than usual digital outputs can supply, and also usually the guaranteed 'logic high' voltage is just 2.4V or so - sufficient to drive a TTL input but not sufficient to drive a solenoid.

I would recommend to add a PhotoMOS relay like the AQV212 by Matsushita. All you need to drive the input side of this ic is a series resistor connected to the input, 390 ohms will be a good choice to connect it to a TTL level output. The output of the AQV212 can handle something like 30V and 300mA. When connecting solenoids or relays to electronic circuitry make sure to add a snubber diode across relay terminals to cut off voltage spikes.

[Sean_C.]

Hello,

LabVIEW comes with many shipping examples which demonstrate various applications. Click on Help >> Find Examples. Once the Example Finder opens, browse to Hardware Input & Output >> DAQmx >> Digital Generation >> Write Dig Chan.vi. This VI writes to eight lines according to the state of the front panel boolean buttons.

I hope this helps. Let me know if you have any further questions.

Regards,
Sean C.