Industrial USB > 13 13-6 www. m oxa. com Introduction to USB Connectivity Industrial USB Serial transmission applications use names such as COM3 and COM4 to identify COM ports. Unfortunately, most USB-to-serial products are unable to use fixed COM names on the host PC. This means that the names of the COM ports change when the USB-to-serial device is plugged into a different USB port, either on the same or a different PC, forcing the user to reconfigure the COM names manually from within the application. Moxa’s UPort® 1200/1400/1600 USB-to-serial hubs have an advanced feature that allows them to use fixed COM names. When the user enables the “COM Preserver™” function, the COM names “go with” the UPort® device. In fact, Moxa’s drivers can even create the same COM port names on a different host PC. With this feature, you do not need to modify application programs, or rebuild the entire project every time you install a new operating system or upgrade the computer. Don’t worry about moving the UPort® from one USB hub to another, or even from one computer to another. Once the COM Preserver™ function is enabled, the names of the USB-to-serial COM ports will go with the UPort® wherever it is used. Note that the COM Preserver™ function is disabled by default. Users can use the traditional method of enumerating COM ports, or enable the COM Preserver™ function to make use of this great new feature. COM port assignment is maintained across different PCs COM port assignment is maintained across different USB ports Moxa’s UPort® 1000 series and UPort® 2000 series of products provide a unique fixed-base COM function that allows users to set a specific initial COM port number. Regardless of which UPort® is plugged into the host, the COM port numbers for the UPort®’s serial ports will be numbered sequentially starting with the initial COM port number. For example, assume that you have set COM10 as the first COM number that will be assigned. If UPort® D1 is plugged into your computer first, your computer will assign COM10 and COM11 to the UPort®’s serial ports. When UPort® D2 is plugged in, the computer will assign COM numbers COM12 and COM13. Moxa’s 25-plus years of experience in serial board design is now built into a new top performance CPU called MOXA ART. This chip equips the UPort® converters with USB 2.0 (Hi-Speed 480 Mbps), a 128-byte FIFO, on-chip hardware and software flow control, and burst data mode, making Moxa’s UPort® converters perform far better than the competition. Top Serial Performance Patented COM Preserver Fixed-Base COM Mode Scenario 1 Scenario 2 Scenario 3 (D1) COM10-COM11 COM12-COM13 (D2) 1 2