USB in Industrial Applications

USB provides a medium bandwidth, non-proprietary port that is rapidly becoming the de facto standard for PCs. USB is a versatile protocol. It uses a multi-drop, half duplex twisted pair, similar in operation to a two-wire RS-485 system. The differential signaling offers a reasonable amount of noise immunity for harsh environments. Power is distributed on the bus as well, so low power peripherals may be operated without an external power supply.

Data rates are high: USB operates at a maximum of 12 Mbps. This opens many possibilities for low cost data acquisition equipment without the burden of proprietary ISA or PCI bus cards competing for space inside the box. The multidrop nature of the bus allows many USB devices to be mixed and matched on the same bus. There are some limitations to USB: operating distances are very limited. Any bus segment cannot exceed 5 meters. There is no provision for securing cable connections.

B&B Electronics is addressing the advances of USB into the industrial area. USB to RS-232/422 and RS-485 converters allow the use of legacy equipment with newer PCs. Booster cords, in effect single port hubs, allow greatly increased operating distances. Count on B&B to continue to be your source for data communications tools!