POS Technical Documents

What's the difference between Metrologic's low-speed USB and full-speed USB?

Metrologic's line of products includes both low & full speed USB scanners. There are several differences between the two. Low speed USB transmits at 1.5 megabits per second (Mbps) and has a maximum cable length of three meters (approx 10 feet). Full speed USB transmits at 12 Mbps and has a maximum cable length of five meters (approx 16 ft). With each transmission speed, there are different communcation protocols supported.

For our low speed USB products, we support two protocols, keyboard emulation and serial emulation. With our keyboard emulation products, the necessary driver is called an HID keyboard driver. This driver is shipped as part of the Microsoft Windows operating systems. With our serial emulation products, a special Metrologic written driver is available that will create a virtual COM port on the host system. This virtual port can only be accessed through standard serial (RS-232) communication programs, but will only support communication from the scanner to the host. This cable will connect to a standard Type A USB port.

For our full speed USB products, we support ony the IBM SurePOS protocol. This protocol utilizes a HID driver that is a standard part of Microsoft Windows operating systems. While this protocol does not support standard keyboard or serial emulation, Metrologic has written several programs that will allow our customers to obtain keyboard (Metrologic's SoftWedge program) or serial data (Metrologic's OPOS driver) from our full speed USB scanners. This cable has a Power Plus USB connector and will not connect to a standard Type A USB port.