What to Note when Desiging an USB Camera

The paper describes several points that can be useful for those who have decided to develop they own camera or a vision system transferring data to the computer via Universal Serial Bus (USB). It is substantiated why the camera, which has a number of unique properties and functionality not typical for cameras in general but required for the specific scientific or industrial equipment, should be designed as a composite USB device. Such device consists of so-called driverless camera (video class device) and one or several additional communication devices implemented as virtual serial ports. In the operating system they are provided as separate independent devices, while actually it is the single device attached to the computer with the single cable. The arguments are given as to why other techniques may be worse comparing to the proposed one. The article gives a number of not so obvious but at the same time useful tips. Explanatory examples of the implementation are presented in schematic form. Also, the discussions on the need to use an additional hardware are provided.