Sensor actuator bus system
US5469150A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 27, 1994 |
| Grant date | Nov 21, 1995 |
| Priority date | — |
| Expiry date | Dec 27, 2014 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P90/02
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A four-wire bus is provided with a two-wire power bus and a two-wire signal bus and a plurality of sensors and actuators attached to both two-wire busses. A modification is provided to the standard CAN protocol developed and provided by Robert Bosch GmbH, in which the standard CAN header, of a data packet is modified to incorporate a shortened device identifier priority. By shortening the identifier field of the CAN header three bits are made available for use as a short form protocol data unit which can be used to contain binary information representing both the change of status of an identified device and the current status of the device. The same three-bit PDU can be used to acknowledge receipt of the change of status information. In order to retain all of the beneficial capabilities of the standard CAN protocol, the three-bit short form PDU can also be used to identify the use of additional bytes of a data field so that a device can take advantage of the more complex capabilities of the standard CAN protocol. However, in situations where a mere change of status report is sufficient, the present invention reduces the length of a message from a minimum of three bytes to a length …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.