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3 Usage

The usage of kacq is very simple.

3.1 Configuration

All the configuration of the recording and oscilloscope is done via the preferences dialog.

3.1.1 Comedi preferences

The comedi page of the preferences dialog allows you to set the sampling rate for acquisition. This page also displays the number of cards on the computers, the name of the cards and the comedi drivers used to interact with the cards. The total number of channels available for recording is also displayed. That is the first place to look to know if kacq has detected your hardware correctly.

3.1.2 Channels settings

The channel page allows you to select the channels you want to record and display. By default, they will all be selected.

3.1.3 Saving settings

The saving page allow you to select a directory where the data will be stored during recording. Although you could save the data on a remote file system, this is not recommanded as a slow network could interfere with the recording.

3.1.4 Oscilloscope settings

Via the the oscilloscope page of the preference dialog you can swich the oscilloscope on or off. One reason to swich off the oscilloscope is to run the program from a remote computer via a ssh -X session. Disabling the oscilloscope reduces the information sent over the network. That could also be useful if you have a really slow computer or a graphic card with limited capability. The oscilloscope has several pages. Up to 8 channels can be displayed on each page. You can also change the colour, gain, offset and page for each channel.

3.2 Recording

To record you need to press the red record button on the toolbar. This will start getting data from the card if it was not already done and will save the selected channels to the file. You can change the file name via the text entry located at the bottom left of the window. There is a file index which increses by one each time the recording is stop. This index will be added to the file name. To stop the recording, just press once again on the red record button.

3.3 Looking at the data

The oscilloscope allows you to look at the raw data as they are being acquired. You can activate the oscilloscope by pressing on the play button. The oscilloscope allow you to move back in time. You need to first press the pause button. The use the rewind button to move back in time.