Sometimes the filenames contain information about channel names.

1. Choose Selection > Detect Channel Names... to open the Detect Channel Names dialog box. Here you can define a pattern that matches a channel name and map it to a resulting channel.
   You can use this mechanism to import multiple input files with a single channel into a single file with multiple channels.
   
2. If your import data contains more than one channel use Add to create another channel for your import result.
   
3. Use Update preview to check, if your channel patterns match with your import data.