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External triggering using LL Grab in IMAQdx

Hello all,

                I am trying to develope a vi for external triggering of image acquisition and processing using IMAQdx low level grab for controlling number of buffers for example saywhen i need more than 5 buffers.

 

I took help of examples from Hardware input and output>>IMAQdx>>Low level >>Low level grab.vi and  Hardware input and output>>IMAQdx>>Signal input and output>> Triggered grab.vi.

 

I tried to understand and used trigger control attributes like trigger mode, trigger activation as it is explained in Triggered grab.vi. but failed to run successfully my vi.

 

Any comments and suggestions about where i might be going wrong???

 

I have attached my vi to this post. I also want to use counter pulse generation in sync with this acquisition using DAQ board.

 

Using Labview 8.2. 

Message Edited by viswa on 03-11-2010 01:17 PM
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Your code seems to work for me, with the exception of how you exit the main loop. You want to "or" your two exit conditions I believe. Also, I had to change the "Subtracted image" to be created as an I16 because that is what my camera was returning.

 

Eric 

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Hello Bluecheese,

                                 The vi runs properly but the trigger mode automatically goes from Mode0 to off when i run the vi. 

 

I am unable to find out why it is doing so?

 

Partly i guess that is due to the boolean result from trigger parameters which is controlling acquisition.

 

Could you postback your modified vi? Also do you see the frame rate same as applied trigger frequency?

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I see the problem. It is the driver. I used initially Legacy IEEE1394 driver for configuring my camera, so it did not work with the attributes properties for controlling camera mode. Now i have upgraded the driver to NIIMAQdx. Now the camera is acquiring images but the frame rate is not the same as the triggered pulse frequency.

 

I am trying to sort it out by changing the exposure time and packet size of data transmission. will let you know if it works.

 

 

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