Method and device for reading a serial data stream

Patent metadata

Field	Value
Publication number	US-2016164535-A1
Application number	US-201514953509-A
Country	US
Kind code	A1
Filing date	Nov 30, 2015
Priority date	Dec 8, 2014
Publication date	Jun 9, 2016
Grant date	—

Abstract

A method for reading a serial data stream in a piece of automation technology equipment includes encoding the data stream to include at least two symbols which are distinguishable by a time interval between two successive signal edges. The data stream is delivered to a read unit including a symbol recognition unit which associates a time sequence of the signal edges with a respective one of the symbols taking into account a period of time including a current symbol duration of one of the symbols to be currently associated and at least one old symbol duration of a preceding one of the symbols.

First claim

What is claimed is:

1 . A method for reading a serial data stream in a piece of automation technology equipment, the method comprising:
encoding the data stream to include at least two symbols which are distinguishable by a time interval between two successive signal edges; delivering the data stream to a read unit including a symbol recognition unit which associates a time sequence of the signal edges with a respective one of the symbols taking into account a period of time including a current symbol duration of one of the symbols to be currently associated and at least one old symbol duration of a preceding one of the symbols.

2 . The method as recited in claim 1 , further comprising synchronizing, by a synchronization unit connected upstream of the symbol recognition unit, the data stream with a clock signal, and delivering the synchronized data stream to the symbol recognition unit.

3 . The method as recited in claim 1 , further comprising outputting, by the symbol recognition unit, information about a sequence of the symbols to an evaluation unit for further evaluation.

4 . The method as recited in claim 1 , wherein the symbol recognition unit includes an association unit, the method further comprising receiving, by the association unit, at least one of the following values:
the current symbol duration and the at least one old symbol duration; a sum of the current symbol duration and the at least one old symbol duration; a sum of the current symbol duration and a deviation of the at least one old symbol duration from an ideal duration; or a sum of the current symbol duration, the deviation of the at least one old symbol duration from the ideal duration and an offset value, wherein, in the association unit, the current symbol duration is associated with a respective one of the symbols based on the received values.

5 . The method as recited in claim 4 , wherein the association is performed by comparison with decision intervals.

6 . The method as recited in claim 1 , wherein the encoding is performed using an encoding scheme which is a Manchester encoding scheme in which the data stream contains a sequence of short symbols and long symbols.

7 . The method as recited in claim 1 , further comprising using decision intervals which are installation-dependent and are stored in a memory unit.

8 . A device for reading a serial data stream in a piece of automation technology equipment, the device comprising:
a read unit configured receive a data stream that is encoded to include at least two symbols which are distinguishable by a time interval between two successive signal edges, the read unit including a symbol recognition unit configured to associate a time sequence of the signal edges with a respective one of the symbols taking into account a period of time including a current symbol duration of one of the symbols to be currently associated and at least one old symbol duration of a preceding one of the symbols.

9 . The device as recited in claim 8 , further comprising a synchronization unit connected upstream of the symbol recognition unit and configured to synchronize the data stream with a clock signal and to deliver the synchronized data stream to the symbol recognition unit.

10 . The device as recited in claim 8 , wherein the symbol recognition unit is configured to output the information about a sequence of the symbols to an evaluation unit for further evaluation.

11 . The device as recited in claim 8 , wherein the symbol recognition unit includes an association unit configured to receive at least one of the following values:
the current symbol duration and the at least one old symbol duration; a sum of the current symbol duration and the at least one old symbol duration; a sum of the current symbol duration and a deviation of the at least one old symbol duration from an ideal duration; or a sum of the current symbol duration, the deviation of the at least one old symbol duration from the ideal duration and an offset value, wherein the association unit is configured to associate the current symbol duration with a respective one of the symbols based on the received values.

12 . The device as recited in claim 11 , wherein the association unit is configured to perform the association by comparison.

13 . The device as recited in one of claims 11 , wherein the symbol recognition unit is configured to generate the values.

14 . The device as recited in claim 8 , wherein the data stream is encoded with an encoding scheme that is a Manchester encoding scheme in which the data stream contains a sequence of short symbols and long symbols.

15 . The device as recited in claim 8 , further comprising a memory unit storing an installation-dependent decision interval.

Assignees

• Heidenhain Gmbh Dr Johannes

Inventors

• Schenzinger Daniel
• Kreuzer Stephan

Classifications

• G06F13/4295 Primary

  using an embedded synchronisation · CPC title

• H03M5/12 Primary

  Biphase level code, e.g. split phase code, Manchester code; Biphase space or mark code, e.g. double frequency code · CPC title

• H04L2001/0094

  Bus · CPC title

• H04L12/40032

  Details regarding a bus interface enhancer · CPC title

• H04L1/0001 Primary

  Systems modifying transmission characteristics according to link quality, e.g. power backoff (adaptive data allocation for multicarrier modulation H04L5/0044; controlling transmission power for radio systems H04W52/04) · CPC title