- NB: Document based on OpenViBE >= 0.18.0
With this feature we offer the user the possibility to select channels at the acquisition server level and thus only give the acquisition client the data it needs.
Let us consider a device that records EEG on 32 channels but we only need some of them. To use the channel selection we need to name only the channels we need. Usually, after naming those channels, we would have something like this :
Name the channels you need and un-name the ones you do not in the drivers properties. You may only need to do this once and save this configuration in a txt file (save button) and load it when you need it (load button) :
You should obtain (The acquisition server name ‘Channel index’ the channels that have no name) :
To ask the acquisition server to only record the named channels, you need to set the corresponding checkbox in the preferences menu :
Then you will see that only the named channels are displayed :
With this there is no need for a channel selector in the designer. See the following OpenViBE scenario for example :
In the usual case, with a channel selection done with the Channel Selector box the previous scenario would display :
As you see the Acquisition client receives a lot of zeroes from the channels that do not record.
With the channel selection done at the acquisition server level, we would have :
Only the relevant data is transferred.