Interface between a processor system and peripheral devices used in a mailing system

摘要

A peripheral interface board establishes a communications link between a postage value determining system processor associated with a postage scale and a plurality of peripheral devices. The interface includes a microcomputer which receives data and command signals from the system processor. A multiplexer interconnects the peripheral transmit line of the microcomputer with a selected peripheral device, while a further multiplexer interconnects the peripheral receive line of the microcomputer with the selected peripheral device. Typical mailing system peripheral devices include electronic postage meters, an electronic accounting system, a scale computer interface and a printer. In response to command signals from the system processor, the microcomputer establishes a communications link with a selected peripheral device. Communications subroutines include signal transmission and/or receipt, temporary storage of data received for communication to or from a peripheral device and communication with the system processor.