Abstract: An interface (12) for coupling a serial port (14) of a computer (16) to a bar code scanner (18). Electrical power required by the bar code scanner is delivered from the serial port of the computer. The bar code scanner is operated in either a reduced-power mode in which it is not scanning or in a higher power scanning mode. The interface may include an energy storage device (36) for storing energy from the serial port when the bar code scanner is operated in the reduced-power mode. When the bar code scanner is used for scanning, the energy storage device supplies the additional power required. In one embodiment, unformatted pulse data output from the bar code scanner are conveyed by data lines to a decoder (34) disposed in the interface. The unformatted pulse data are processed by the decoder to produce formatted data that are input to the serial port.

Abstract: An interface (12) is disclosed for coupling a peripheral device (18) to the serial port (14) of a computer (16). in one application, the interface allows the serial port to provide the power required by a scanner for operation. To reduce power consumption, the scanner is typically operated in either/a reduced-power, nonscanning mode or a higher power scanning mode. The interface may include an energy storage device (36) for storing energy from the serial port when the scanner is operated in the nonscanning mode and providing energy to the scanner when it is operated in the scanning mode. Thus, a scanner that requires more power than the serial port can provide at any one time can be used. The interface also includes a shutdown circuit (46) that prevents the scanner from being operated in conditions that might lead to the erroneous interpretation of data. Further, an input leakage isolation circuit (48) is included to prevent the discharge of the storage device when the scanner is not in use.

Abstract: An interface (12) is disclosed for coupling a peripheral device (18) to the serial port (14) of a computer (16). In one application, the interface allows the serial port to provide the power required by a scanner for operation. To reduce power consumption, the scanner is typically operated in either a reduced-power, nonscanning mode or a higher power scanning mode. The interface may include an energy storage device (36) for storing energy from the serial port when the scanner is operated in the nonscanning mode and providing energy to the scanner when it is operated in the scanning mode. Thus, a scanner that requires more power than the serial port can provide at any one time can be used. The interface also includes a shutdown circuit (46) that prevents the scanner from being operated in conditions that might lead to the erroneous interpretation of data. Further, an input leakage isolation circuit (48) is included to prevent the discharge of the storage device when the scanner is not in use.