generate digital voltage cycle for controlling solenoid valves

[Vikrantrai01]

Hi,

I want to generate digital voltage cycle (0 V-15 V-0 V-15 V...) so as to turn on and off solenoid valves. The valves should open for at most 1-2 sec and then remain close for 30-40 seconds. I am using a DAQ card PCI-6503 and electromechanical relay ER-8 to send out digital voltages. I have no experience in using DAQ cards and stuff. Can someone please help me out in writing such simple VI? I would really appreciate if there is a similar tutorial on above mentioned problem.

Thanks,

Vikrant

[MickeyD]

Hi Vikrant,

The best way to implement your program is by modifying pre exisiting examples.  It really depends how accurate you need the timing to be if the windows millisecond clock is accurate enough, then you can simply run this in a while loop and have it programatically change after a number of iterations, or start over each time.  Please let me know which version of LabVIEW you are working with, and I can post the example I would look at.  If you have a little familiarity I would recommend using the example finder.  You can find it by clicking on  find examples in the bottom right of the startup screen.  Once there go to

Hardware Input and Output » DAQmx» Digital Generation » Write Dig Chan or Write Dig Port.

Placing a while loop around either of those would give you a great starting point.

Let me know what version of LabVIEW you have an what kind of timing is necessary for your application, and if you have trouble finding those examples let us know, but this application should be no problem to get setup.

Have a great day,

Michael Denton

[Vikrantrai01]

Thanks a lot for your help. I have both versions as in Labview 7.1 and the latest 8.2.1. Even I saw some VIs posted in different forums for controllng solenoid valves. The only concern I have is how to use DAQ to generate voltage or rather I should say how do I know whether I am getting the output I want?

Anyways, I appreciate your help and hope to get few good examples.

Thanks again,

Vikrant

[Robert_F]

Hi Vikrant,

You can use a DMM to measure the output of the PCI-6503.  You could also route the digital output signal to another digital input and measure that signal on the test panel in Measurement & Automation Explorer (MAX). 

[Vikrantrai01]

Thanks a lot. Fortunately I have DMM. Really appreciate your help. I have downloaded some VIs for controlling solenoid valves. Hope it works.

Vikrant

[vinoth002]

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@Robert_F wrote:

 You could also route the digital output signal to another digital input and measure that signal on the test panel in Measurement & Automation Explorer (MAX). 

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Hi Robert,

Could you tell me how to do this?

Thanks

Vinoth

[Robert_F]

Hello,

Glad to Vikrant you have it under control.

You would physically wire the digital output pin to the digital input pin.  Open a test panel in MAX and then run your application. 

[Vikrantrai01]

Hi,
I am just wondering whether I need an external power supply in order to send out voltages to my solenoid valves. Will the PCI card draw power from the computer? Because if thats the case, how do I know how much voltage I am getting as an output?
Just to mention, I have following things...
PCI 6503 card
Electromechanical relay ER 8

My solenoid valve is just a valve and has no logic built into it. It just takes 15V to open and 0V to close. Please help me out with this issue.

Thanks once again

Vikrant

[Robert_F]

Hello Vikrant,

Is your relay going to be able to switch if a TTL compatible signal is applied?  The PCI-6503 can only output digital signals that are TTL compatible (0V – 5V). 

[Vikrantrai01]

Hi,
Thanks for your help. I finally figured it out. I used an external power supply to switch on and off my solenoid valves.

Also I got a VI which will work for my application. Once again, I appreciate your help.

Vikrant