Electronic postage meter having plural computing systems
US4422148A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 6, 1981 |
| Grant date | Dec 20, 1983 |
| Priority date | — |
| Expiry date | May 6, 2001 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG07B2017/00346
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
An electronic postal meter has a control unit, an accounting unit and a printing unit, each incorporating a CPU having a separate crystal controlled clock. Communication between the units is serial character asynchronous, bit synchronous, in message form, with the bits of the messages being timed in accordance with a given schedule for synchronous control. The messages themselves, upon receipt by a receiver, are returned bit by bit to the transmitter, for checking, whereupon the transmitter sends a no-error pulse upon successful comparison of the transmitted message and the message received from the receiver. All control and data signals utilize the same pair of conductors in each direction with precisely defined timing for control.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.