start button on PCI 6250

[wang]

Hi,

I input  a analog voltage into PCI 6250 board and use ohm law to get the current.

The question is how am I put a start button on the inputting voltage using digital I/O. The AI voltage does not

have a data input for me to wire.

Attached is my sample. Pls take a look

[Dennis_Knutson]

see here. This question is also confusing since you ask about a start button but also mention digital I/O. What exactly are you asking for?

[wang]

Hi,

I put a reset.vi button on my sample application. It did not allow me to wire the input from physical task constant to DAQmx reset vi input

why?

The second question. I got a on and off switch on my test fixture. In order to generate a CD current out to the test fixture. I need to

turn on the switch. I know Labview can put a reset button and reset everything of your application. How about a on and off switch?

Can Labview put a on and off switch to control the test fixture power??  I am in a urgent. Pls you pls send me quickly?

Many thanks!

[Dennis_Knutson]

You're talking about DAQmx Reset Device? If so, then no, it does not have a Boolean input. Whenever you call it, it will reset the device. So, you have to write a program that will call the function only when the control is true. You can use an event structure for the front panel boolean and in the value change event, you put this function.

Well, LabVIEW by itself cannot control anything. You need something that interfaces the LabVIEW program to the test fixture. This could be a DAQ board that controls some relays as an example.

[wang]

Hi,

Do you have an example for what you said?

Especially you are talking about event structure

[Dennis_Knutson]

You have the shipping examples (Help>Find Examples). You were also given a great example here when you asked the same question. You should check into the LabVIEW Learning Center and take a class, read a book, or on-line tutorial.

[wang]

Hi,

My actual problem is that I have a test fixture with power on and off switch, a 6V to 4V switch, a reset button, enable button,

beep button and a shock test button.

I want to put all these buttons into my Labview program so that I don't have to manually adjust the button on the test fixture.

Can I do it in Labview using PCI 6250? Can NI 5112 board can also do this thing too?

I am in a urgent. I appreicate if you can reply to me promply

[Dennis_Knutson]

You can easily create some controls in LabVIEW that interface to your 6250 DAQ board. The 5112 is a digitizer so it doesn't have any outputs you can use for control. If you want to replace the switches in your fixture, one way is to use relays instead. Then the digital I/O of the 6250 can interface to the relays through a relay driver (since the digital I/O can't source enough current).

[wang]

Hi,

Thanks for your answer.

Do you have any more information on relay? Is it a NI product and some software dirver?

If so, can you direct me to the infomation I can look at.

Is that common way people usually replace switches on the test fixture to the digtial I/O for PCI 6250 boards?

If so, I like to follow this kind of ways. If not, can you suggest somer others

[Dennis_Knutson]

A relay is a basic electronic element. A short definition is "An electrically activated mechanical device that opens and closes electrical contacts.". It's a coil that when a current passes through it, generates a magnetic field. The field causes an actuator to move, closing a set of contacts. Think of it as a switch that's controlled by the application of an external voltage. I think that if you don't have any working knowledge of basic electronics, you're going face more problems than just not knowing anything about LabVIEW. You're going to have to find someone where you work who can make an informed decision about modifying what you have.