Serial data bus and use thereof
First Claim
1. A serial data bus for communicating data messages having a plurality of bits, said serial data bus comprising:
- (a) a plurality of bus nodes, each of said bus nodes for functioning as a master;
(b) a central unit connected to said bus nodes for determining positive and negative phases of operation for said serial data bus, providing timing for said serial data bus, controlling the synchronization of said serial data bus, supplying current to said bus nodes during said positive phase, and for functioning as a master; and
(c) a two-wire line connecting said bus nodes with said central unit over which said data messages are communicated to and from said central unit and said bus nodes in a prioritized manner regardless of whether a previous data message is presently being communicated, and wherein each bit of said data messages is transmitted during said negative phase over said two-wire line.
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Accused Products
Abstract
A serial data bus with a two-wire line and a plurality of bus nodes for the exchange of data messages in both directions between the bus nodes and a central unit connected to the bus and for the current supply of the bus nodes. Conflicts between data messages that appear simultaneously are resolved on the basis of the priority thereof. The bus is constructed in the manner of a multi-master system in which each bus and the central unit is a master, and the central unit provides the bus timing and controls the synchronization of the bus. Each bit transmission is divided up into a positive and a negative phase, the current supply of the bus nodes being effected in the positive phase and the data transmission being effected in the negative phase.
The bus is preferably used for a hazard-detection system wherein the bus nodes comprise a micro-controller and either are constituted by special detectors with integrated bus or comprise an interface for the connection of the detectors. Bus protocol and bus timing are coordinated with the micro-controllers in such a way that the latter can take over the operation of the bus.
29 Citations
15 Claims
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1. A serial data bus for communicating data messages having a plurality of bits, said serial data bus comprising:
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(a) a plurality of bus nodes, each of said bus nodes for functioning as a master; (b) a central unit connected to said bus nodes for determining positive and negative phases of operation for said serial data bus, providing timing for said serial data bus, controlling the synchronization of said serial data bus, supplying current to said bus nodes during said positive phase, and for functioning as a master; and (c) a two-wire line connecting said bus nodes with said central unit over which said data messages are communicated to and from said central unit and said bus nodes in a prioritized manner regardless of whether a previous data message is presently being communicated, and wherein each bit of said data messages is transmitted during said negative phase over said two-wire line. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A hazard-detection method comprising:
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prioritizing data messages on a serial data bus; operating each of a plurality of bus nodes as a master; operating a central unit as said master; determining positive and negative phases of operation for said serial data bus; providing timing for said serial data bus; controlling the synchronization of said serial data bus; supplying current to said bus nodes during said positive phase; and transmitting said data messages during said negative phase between said central unit and said bus nodes in a prioritized manner regardless of whether a previous data message is presently being communicated. - View Dependent Claims (13, 14, 15)
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Specification