The network structure can be up to six levels deep. As always only one USB device can be connected to one USB socket, distributors (hubs) must be used. Up to 127 different devices can theoretically be connected to the USB bus: this is done in the form of a star topology. The bus specification involves a central host controller, this master takes over the coordination of the connected peripheral devices called slaves.Data transmission is possible in both directions: camera control, triggering, parameterisation is equally possible during operation.USB cables are therefore quite interference-free, have a thin cross-section and can easily be laid in an industrial environment. The signal level between 1 and 0 is thus twice as high, interferences can widely be eliminated.
The signal receiver evaluates the voltage difference of both signals. The data transmission is always symmetrical, one conductor transmits the data signal, the other always the inverted signal. In addition to two conductors for the voltage supply, two other conductors (D+ / D-) are required which are twisted.
A wide market launch is expected for 2010. USB 3.0, also called super-speed USB, is supposed to increase the transmission speed to up to 4.8 Gbit/s. In 2009 the first chipsets for the next generation of USB were presented to an expert audience. In case of industrial cameras, too, this interface is well established on the market and predominantly serves for cheap applications. The voltage supply is also integrated in the cable. 40 MB/s net) which is sufficient for many applications.
USB 2.0 corresponds to a data rate of 480 Mbit/s (approx. For a number of years, several USB 2.0 ports have been a standard in every PC. The USB 2.0 interface was specified in 2000 and shortly afterwards integrated into mainboard chipsets. Due to the maximum data rate of 12 Mbit/s, the use in machine vision was unthinkable.
USB 2.0 CAMERA PC PC
The aim was to harmonise and simplify the different interfaces of the PC for peripheral devices (mouse, keyboard, modem, printer, scanner. Already in 1996 the USB interface was developed by Intel and introduced onto the market as USB 1.0.