Capture keystrokes while VI running in the background.

Hi
I have a VI that needs to run in the background, however I need it to be able to recognize a certain string when typed in on the keyboard, actually it's a barcode reader - same difference. I have tried to use the keyboard.zip file from the ftp site however the VI's don't seem to work unless they are in focus. How do I do this with the program running in the background??
Thanks
Jacob Thastrup
BioImage A/S
www.BioImage.dk

Jacob,
Get the VI called Get Keys.vi (or something alike) from our online (free)
library, www.air.nl. Maybe it needs some small modifications, but it should
do the job.
However, barcode scanners are not exactly the same as user input. In theory,
yes, in practice, no. Problem is they are very fast. So, you have to scan
the keyboard very fast. Probably too fast (e.g. it's not possible to obtain
all characters from the scanner).
Fortunatlly barcode scanners often have possibilities to add a delay between
characters. Set to a delay of 50 ms (or experiment, until perfect..) and it
should work.
The VI gets keys even if another application is active.
Regards,
Wiebe Walstra.
AIR technical Automation
www.air.nl
"jact" wrote in messa
ge
news:[email protected]..
Thank you for your fast reply. However as far as I could get it to
work it still required me to have a VI in focus. The program running
in front is not a Labview VI so I'm still stuck any other suggestions?
Thanks
Jacob Thastrup

Similar Messages

LabVIEW closes while VI's are still running in the background

I have created a large application that is split between VB 6 and LV 6.1. The LabVIEW portion runs in the background, except that the VB portion can request that a LabVIEW user interface be presented on demand. Any time after this LabVIEW user interface has been opened and closed, opening and closing another application (or even just hiding a top-level window in another application) will cause LabVIEW to close, taking my background processing with it.
If the LabVIEW code is running as source code, LabVIEW prompts me before closing. However, when the LabVIEW code is running as an executable (.exe), the executable closes without prompting in this circumstance.
The scenario can be reproduced with a standard LabVIEW sample program. Proceed as follows:
1) Open VBToLV.vbp (the example program distributed with LabVIEW 6.1).
2) Start the VB program running.
3) Press the Launch LabVIEW button on the user interface of the VB program.
4) Enter an expression in the text box provided.
5) Select Display VI Front Panel.
6) Press the Run VI button.
7) Close the VI front panel by clicking its "X" button.
8) Open any handy application, such as Windows Explorer or Notepad.
9) Close this most-recently-opened program.
10) The LabVIEW Exit screen appears.
11) Exit LabVIEW.
12) Press the Run VI button.
13) An error occurs because LabVIEW has closed.
If the LabVIEW code had been built into an executable and called accordingly, there would have been no LabVIEW exit screen. The executable would have just exited silently.
This is not the way a COM server is supposed to behave. The VB program is still holding a valid reference to the server and it should remain open.
It appears that LabVIEW is monitoring the total number of top-level windows that are open. I suppose that this is how LabVIEW figures out when its own FP windows have been closed. In this case, it doesn't notice that all of its windows have been closed until some other window closes.
I have a work-around, but it's ugly.
Ron Martin
Balance Technology Inc.

Hi,
Perhaps you use references to windows in LabVIEW. If you get those
references with a full path (e.g. c:\code\subvis\vi1.vi), this will work
while in LabVIEW environment. But when an application is build, this will
fail, because the vi is no longer there. Try using the name in a string
instead (the OpenVIReference is polymorphic) with only the name of the vi in
it (e.g. vi1.vi).
There are some other isues that change when building an application. Most of
them are paths that change, and references that fail to open because of
them.
Regards,
Wiebe.
"cpuwzd" wrote in message
news:[email protected]...
> I have created a large application that is split between VB 6 and LV
> 6.1. The LabVIEW portion runs in the background, except that the VB
> portion can request that a LabVIEW user interface be presented on
> demand. Any time after this LabVIEW user interface has been opened
> and closed, opening and closing another application (or even just
> hiding a top-level window in another application) will cause LabVIEW
> to close, taking my background processing with it.
>
> If the LabVIEW code is running as source code, LabVIEW prompts me
> before closing. However, when the LabVIEW code is running as an
> executable (.exe), the executable closes without prompting in this
> circumstance.
>
> The scenario can be reproduced with a standard LabVIEW sample program.
> Proceed as follows:
>
> 1) Open VBToLV.vbp (the example program distributed with LabVIEW 6.1).
> 2) Start the VB program running.
> 3) Press the Launch LabVIEW button on the user interface of the VB
> program.
> 4) Enter an expression in the text box provided.
> 5) Select Display VI Front Panel.
> 6) Press the Run VI button.
> 7) Close the VI front panel by clicking its "X" button.
> 8) Open any handy application, such as Windows Explorer or Notepad.
> 9) Close this most-recently-opened program.
> 10) The LabVIEW Exit screen appears.
> 11) Exit LabVIEW.
> 12) Press the Run VI button.
> 13) An error occurs because LabVIEW has closed.
>
> If the LabVIEW code had been built into an executable and called
> accordingly, there would have been no LabVIEW exit screen. The
> executable would have just exited silently.
>
> This is not the way a COM server is supposed to behave. The VB
> program is still holding a valid reference to the server and it should
> remain open.
>
> It appears that LabVIEW is monitoring the total number of top-level
> windows that are open. I suppose that this is how LabVIEW figures out
> when its own FP windows have been closed. In this case, it doesn't
> notice that all of its windows have been closed until some other
> window closes.
>
> I have a work-around, but it's ugly.
>
> Ron Martin
> Balance Technology Inc.

Upgraded to Lion. Numbers is stalling to auto save after every keystroke. Isn't auto save supposed to run in the background?

Upgraded to Lion. Numbers is stalling to auto save after every keystroke. Isn’t auto save supposed to run in the background?

It's supposed to save when the processor isn't triggered by the user. If you type slowly, time between two strokes may be sufficient to allow it to start the save process.
Yvan KOENIG (VALLAURIS, France) lundi 17 octobre 2011 23:27:47
iMac 21”5, i7, 2.8 GHz, 4 Gbytes, 1 Tbytes, mac OS X 10.6.8 and 10.7.0
My iDisk is : <http://public.me.com/koenigyvan>
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import javax.microedition.media.Manager;
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package main;
import java.io.IOException;
import javax.microedition.lcdui.*;
import javax.microedition.lcdui.game.*;
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}Edited by: VANPERSIE on Jul 10, 2012 12:26 PM

Hi Andi,
Thanks for your reply.
Yes, I have waited for a while and the result doesn't change.
The Porblem here is the application is seen started in visual administrator.Only restart brings up the page back.
Can you please suggest anything.
Thanks and regards
Nagaraj

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I just had a similar experience with my iMac - late 2009. Ty unplugging it and let it sit for a while.
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I've tried doing a spotlight search to try and find the program and delete? It's not in my apps list?
So I'm stuck and need some help? Thank you

That is a LaunchAgent. You will find it in the /Home/Library/LaunchAgents/ or /Library/LaunchAgents/ folder. To delete it you will have to first kill the process in Activity Monitor, then drag the file to the Trash and delete it. If the process reappears, then drag the item to the Trash and restart the computer, after which you can Empty the Trash.
Exposing the /Home/Library/ Folder
Pick one of the following methods:
A. This method will make the folder visible permanently. Open the Terminal application in your Utilities folder and paste the following at the command prompt:
chflags nohidden ~/Library
Press RETURN.
B. Click on the Desktop, press the OPTION (⌥) button, select Library from the Finder's Go menu.
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~/Library
Press the Go button.

HT1338 My special characters screen for pages is running in the background no matter what I do. It randomly pops up and then goes away. I can't close it even though I have closed pages and restarted my computer. How can I stop this.

My special characters screen for pages is running in the background no matter what I do. It randomly pops up and then goes away. I can't close it even though I have closed pages and restarted my computer. How can I stop this.

Try trashing the .plist with CharacterViewer in its name in Home/Library/Preferences. To get to Home/Library you may need to hold the option key down while you do Finder > Go.

Stopwatch continues to Run in the background

Took awhile for this to develop, but the stopwatch resets itself to zero now after just a half hour of running. That's what alerted me to the underlying problem. I've left the stopwatch running for several days in the past. I don't know if that's the trigger for this bug or not.
Basically when i start the stopwatch it runs now for 30 mins, maybe an hour or two, but when I go back in to view it, flashes a VERY long number like "233:13:45" and then flashes to zero. While it should be showing a few hours of work, it shows this extremely long number and then zero's out.
The second time it happened I had the idea of hitting "Lap" instead of "Start" to restart it. In the lap area I saw an extremely long number. Its clear the stopwatch system is continuing to run in the background, possibly from a previous date where I left it running, months ago. It seems to be doing this in the background, as the front end always ultimately goes to zero, even when it should still be running for that particular day. Clear as mud?
Definitely a bug, and Im not sure how you'd duplicate it, but here would be my suggestion:
1) Start the stopwatch and let it run for like 5 to 10 days without stopping.
2) Navigate around the phone and use its other features in the meantime.
3) Stop the stopwatch and reset it to zero, and restart it.
4) Do the same thing. Run it for 5 days maybe.
5) Stop it and reset it to zero.
Eventually it may start zeroing out when it is supposed to be counting upwards. It may also flash a long number, prior to zeroing out. You may also be able to hit "LAP" when it incorrectly zero's out and you may then see the very long number. If so, you've duplicated the bug.

i have the same problem... i have yet to find a way to duplicate the problem at will, but it manifests itself on a fairly frequent basis.
a have been running laps at around 5-6 hours or so. the problem could occur on the 1st lap or on the 6th lap. all of the a sudden the display goes to all 0s, and if you hit lap or stop, the last lap will be over 66000 hours... which, the last time i checked was like over 7.5 years....
while i may have been an early adopter, i have not had my iphone that long....
a stopwatch should be one of the simplest applications to get right. i find it pretty lame that this bug appears.

Capture keystrokes while VI running in the background.

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