Time Stamp - Basler ace acA640-90gm User Manual

11.4 Time Stamp

The Time Stamp feature adds a chunk to each acquired frame containing a time stamp that was
generated when frame acquisition was triggered.
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 on.
The chunk mode must be active before you can enable the time stamp feature or
any of the other chunk feature. Making the chunk mode inactive disables all chunk
features.
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
image.
To retrieve data from a chunk appended to an image that has been received by your PC, you must
first run the image 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 Chunk Enable parameter value from within your application
software by using the Basler 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(),
Result.GetPayloadSize() );
int64_t timeStamp = Camera.ChunkTimestamp.GetValue();
You can also use the Basler pylon Viewer application to easily set the parameters.
For more information about the pylon API and the pylon Viewer, see Section 3 on
Basler ace GigE
Chunk Features
page 27.
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