led glow through parallel port.

[Sippy]

ok I shall try to do play with the example Dennis mentioned and shall get back.

[Sippy]

Just one small doubt In Labview can I program in such a way that I glow an LED using a push button rather than using a toggle button from parallel port? If yes how?

[Dennis_Knutson]

Assuming you are talking about this , then of course. They are exactly the same on the block diagram which you should have been able to check yourself. The difference is totally cosmetic.

[Sippy]

In programming part how will you make a push button work like an toggle switch. I don't want to manually ON and OFF

[RavensFan]

First, be careful with your terminology.  Something that is manually on and off would be a toggle switch.  What you are describing is actually called a momentary switch.

If you want something that will pop back up automatically you need to set the mechanical action of the switch to Latched when released.  The button will stay down once you press and release, and will pop back up automatically once LabVIEW reads its value.

This is basic LabVIEW knowledge.  I would recommend looking at the online LabVIEW tutorials:
LabVIEW Introduction Course - Three Hours
LabVIEW Introduction Course - Six Hours

[Ray.R]

And these:

To learn more about LabVIEW, I suggest you try looking at some of these tutorials.

[Sippy]

The Prolem is I am not able to explain the problem very well.

But I will try again. 

In My hardware..Parallel port hardware is having 8 LEDs (D0 to D7).

and 5 Status port (In the form of Push Buttons) 

Basically I want to access those push buttons(Status port) Like the toggle button.

In the sense that... if i press one push button it becomes 0 and the moment I release that button it comes back to its intially position ie 1. since it is a push button. that means i need to keep holding the button till my work is not done and then release the button.

But in my hardware I cannot change those push buttons with toggle button so that it remains 0 if i press once and if I press again it should go 1.

So basically I need to program in such a way that My push button acts like toggle button. 

Pls don't suggest me to use boolean buttons I cannot do that. I have to access only from hardware.

[RavensFan]

I think I understand.  See the attached code.

Since I don't have hardware, I simulated it with a boolean button that is set for Switch until released, so it acts like a momentary hardware push button.  Replace that control with your Read DAQ function.

I use one shift register to remember its last state and special boolean logic so that it only acts on the transition from false to true.  With that it toggles your output boolean using exclusive OR logic.  That is also maintained in a shift register to remember the current state of your output line.

There may be other ways to implement this logic and even combine the boolean operations a bit more, but this seems to work the way I now understand what you are trying to do.

Message Edited by Ravens Fan on 03-03-2010 10:38 AM