View Full Version : App hangs at livestop
July 11, 2005, 09:53:27
I'm using a DMK21BF04 camera with VB6 and Imagingcontrol 2.1
I have to use still images, triggered by a light barrier. The app works fine, as long as the trigger is in use. I now found that in some cases the application hangs at a livestop and waits for the trigger to act.
The same effect arises when unloading the form with the Imagingcontrol. The process hangs until the light barrier sends a triggering signal.
What could be the reasons for this behaviour?
July 11, 2005, 10:29:18
The problem is that the program hangs in the MemorySnapImage method. I think you use this method. You can solve this problem, if you would use the ImageAvailable event. You set "LiveCaptureContinuous" to true, insert the ImageAvailable event and call startLive().
You do not need to call MemorySnapImage. Every time a frame is delivered, the ImageAvailable event handler will be called.
This means, your application does not block due to wait for a frame.
July 15, 2005, 12:50:55
unfortunately I don't use the said method. Even when only starting the app, doing nothing but loading the MainForm and trying to stop the app: as long as the devicetrigger is set to true the app hangs while unloading until the trigger signal comes from the camera.
Any other idea?
July 18, 2005, 08:03:27
To make sure, everything is understand:
I am developing on a Win2000 Pro System using VB6 Sp5. The camera is a DMK21BF04, I have to use an external Trigger (light barrier) which sends a 12V signal (NC, high value for switching).
The problem arises as soon as the trigger has been activated:
When there was no trigger signal in between starting the trigger and doing anything else (i.E. stopping for a livefeed):
or even only trying to set some properties:
The application then hangs at the livestop method, waiting for a trigger signal. Only when a trigger is sent, the remaining statements will be used.
Please give a reason for that behaviour and a way to avoid it.
Thank you again
July 18, 2005, 08:12:51
Could you please send your project as zipped file to email@example.com, so i can have a look on it? You can write in german in your mail.
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