Basler raL2048-48gm Manuel d'utilisateur télécharger pdf (Page 213)

AW00118302000 Chunk Features

Basler racer GigE 203

11.4 Time Stamp

The Time Stamp feature adds a chunk to each acquired frame. The chunk contains a time stamp

that was generated when the frame start trigger for the frame became valid.

Note that when the camera is set for continuous acquisition mode with the frame start trigger set to

off, the user is not required to apply frame start trigger signals to the camera. In this case, the

camera will internally generate a signal that will be used for the stamp.

The time stamp is a 64 bit value. The time stamp is based on a counter that counts the number of

"time stamp clock ticks" generated by the camera. The unit for each tick is 8 ns (as specified by the

Gev Timestamp Tick Frequency). The counter starts at camera reset or at power off/on.

Enabling the Time Stamp and Retrieving Chunk Data

To enable the Time Stamp chunk:

 Use the Chunk Selector to select the Time Stamp chunk.

 Use the Chunk Enable parameter to set the value of the chunk to true.

Once the time stamp chunk is enabled, the camera will add a time stamp chunk to each acquired

frame.

To retrieve data from a chunk appended to a frame that has been received by your PC, you must

first run the frame and its appended chunks through the chunk parser that is included in the pylon

API. Once the chunk parser has been used, you can retrieve the time stamp information by doing

the following:

 Read the value of the Chunk Time Stamp parameter.

You can set the Chunk Selector and the Chunk Enable parameter value from within your application

software by using the pylon API. You can also run the parser and retrieve the chunk data. The

following code snippets illustrate using the API to activate the chunk mode, enable the time stamp

chunk, run the parser, and retrieve the frame counter chunk data:

// make chunk mode active and enable Time Stamp chunk

Camera.ChunkModeActive.SetValue( true );

Camera.ChunkSelector.SetValue( ChunkSelector_Timestamp );

Camera.ChunkEnable.SetValue( true );

// retrieve data from the chunk

IChunkParser &ChunkParser = *Camera.CreateChunkParser();

GrabResult Result;

StreamGrabber.RetrieveResult( Result );

ChunkParser.AttachBuffer( (unsigned char*) Result.Buffer(),

The chunk mode must be made active before you can enable the time stamp

feature or any of the other chunk features. Making the chunk mode inactive

disables all chunk features.

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Basler raL2048-48gm Manuel d'utilisateur Page 213