Azatrax has released two IR(infrared) model train detection circuits that connect directly to a computer via USB (Universal Serial Bus). The new devices, model MRD2-U and MRD2-S, enable computer monitoring and control of the layout without burdening the DCC train control system. The model MRD2-U is a dual IR model train detector that informs the computer whether trains are present at either of two locations on the track. It also provides timing information so the computer software can calculate train speed and direction. Model MRD2-S is a dual IR model train detector that also controls a track switch. The switch can be set automatically by the infrared detectors, or by commands from the computer or manual push buttons. Connecting layout accessory control circuits to the computer directly via USB offers advantages including simplicity, reliability and better train control response. The accessory controls and software can also remain in place when the DCC system is changed or replaced with new technology. When train detectors and automatic controls are first added to a layout, they're often connected to the DCC train control system. It's an obvious choice... the DCC system is there, and you can control it with the cab controls. But the DCC standard was meant for one-way, low bandwidth communication for controlling trains only. As a layout grows, adding layout controls (train detectors, switch actuators, etc.) to a DCC system bogs it down and train control response time suffers. When layout control is coordinated by a computer, connecting the detectors and automation circuits to the computer via USB disentangles them from the DCC system. This frees up the DCC system to do what it does best - control the trains. The control of the layout is entirely separate. Detection and accessory circuits and software can remain in place when the DCC system is changed or replaced by a newer technology. The MRD2-S and MRD2-U detectors are currently supported by Deepwoods Software's Model Railroad System: www.deepsoft.com/home/products/modelrailroadsystem USB is an open standard, and open source USB communication utilities/API's are available for Windows, Mac OS and Linux at www.libusb.org More information is available at: www.azatrax.com/usb Azatrax specializes in the design and manufacture of model railroad infrared sensors, crossing signal controls and layout animation devices. Azatrax P.O. Box 6763 Longmont, CO 80501 www.azatrax.com