7167 Owner’s Manual Chapter 3: Solving Problems
November 2003
22
ut the Universal Serial Bus
The Universal Serial Bus (USB) is a peripheral bus for personal computers that was first released in
January 1996. Since that time, virtually all Intel Architecture personal computers have the hardware to
support USB, and a large number of computers exist that have both the hardware and software
support required to interface with USB peripherals.
Advantages of USB connections
USB has a number of advantages over legacy connection schemes (e.g., serial RS-232). These
advantages include:
• High Speed: up to 12 MB/second for high-speed devices.
• Plug and Play: Devices are automatically recognized and configured at installation.
• Hot plug: Bus supports installation and removal of devices with the power applied.
• Up to 127 devices: One host can support up to 127 devices with the use of hubs.
• “Free ports”: Most PC architecture machines contain two USB ports in the base hardware.
These advantages have become attractive to the POS industry for a couple of reasons.
Additional POS devices. Some POS systems are required to host more peripherals than can be
supported by two RS-232 ports typical in a platform. With the addition of one (or two) USB
connectors, the platform can now support the additional devices that had previously required a serial
port expander card.
Higher bandwidths. New devices coming into use have bandwidth requirements that are higher
than the bandwidth that can be supported on legacy interfaces. These devices include image scanners
and printers. As the speed and capability of POS printers increases, the performance of the printer in
an application can become limited by the speed of the communications interface. USB provides ample
bandwidth to support current and future POS printer requirements.
Advantages of the NCR USB Solution
NCR has eliminated any cost associated with porting applications to USB by implementing a USB
solution that simulates standard serial communications in Windows 98 (SR2), Windows 98 USB Hot
Patch, ID: Q236934, NT 4.0 (Service Pack 3 or higher) and Windows 2000. Application developers
need only redirect their software to the virtual serial ports created by the NCR USB solution to use the
printer.
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