DE10227531A1 - Procedure for confirming correct message transmission e.g. for data-busses in means of transport, involves overwriting part of status vector in received nodes during correct transmission of message or transmission - Google Patents

Abstract

A method for confirming an information transmission between nodes of a databus system, in which certain messages/information are assigned a confirmation vector (3). The conformation vector (5) indicates if previous messages or information were correctly or not correctly transmitted and in which a status vector is provided in several nodes. With correct transmission of a message/information, a zone of the status vector (2,4) is over-written in the received nodes and in a message configured therefore, a copy of a status vector is sent from at least one node as a conformation vector (5) and is stored. In each node on the basis of the status vector stored there, it can be established which message/information was correctly or not correctly received by the other node.

Description

-Method for confirmation a message transmission between nodes of a data bus system in which each message is inserted confirmation vector is assigned, the confirmation vector transmitted along with the message from one node to the next and at which the acknowledgment vector indicates whether one or more previous messages are correct or not transmitted correctly were each provided with a status vector in multiple nodes is in that for predetermined messages information is stored, whether a message was received correctly or incorrectly.

In connection with the news transmission For example, in data buses, a CRC codeword (cyclic redundancy check) with the message. In the receiving node, for example, a control unit, can then due to the CRC code word be recognized whether the message is transmitted correctly or incorrectly has been. In case of faulty transmission the message is, for example, retransmitted. For data buses for security applications However, like brake-by-wire procedures, it is often not possible in time a second transmission to carry out the message. As a result, it is advantageous to work with state vectors in which for Several messages are recorded to see if a message is correct or not transferred has been.

It is an object of the present invention Procedure for Specify data buses in means of transport in which due to status vectors is recorded, whether a message is received correctly or a program performed correctly and at the for all nodes on the data bus are checked can correctly convey which of the information in another node has been.

This task is characterized by the features of claim 1. After that, if the transfer is correct a message an area of the status vector in the receiving node described and in one for that configured message becomes a copy of a status vector of a Node as acknowledgment vector sent from at least one node to other nodes on the data bus and stored there, so that in each node due to there stored status vector can be determined which messages received correctly or incorrectly at the other nodes. The task is relative to correct program execution also solved by claim 2.

The procedure provides within the Data Bus Systems Diagnostic information from two different perspectives to disposal. On the one hand, in the status vector, information related to the message sender get saved. The status vector indicates whether a particular one Message from other nodes was received correctly or incorrectly. To the status vector of the message recipient is copied and marked with a especially for the confirmation was configured Message distributed in the data bus to the news channels. It can it is a message sent cyclically in the data bus.

On the other hand, the status vector a message recipient specify whether a received message from other nodes is correct or received incorrectly. The method may, for example, in the context with a FlexRay data bus containing cyclic message periods has synchronous time slots and asynchronous time ranges, be applied.

In a development of the method certain nodes on the data bus become so-called acknowledgment groups in a nutshell, for the example. A highest Security level required for message transmission on the data bus becomes.

On the other hand, the confirmation groups rather than being limited to certain nodes, even by particular ones Messages are defined, which are then checked for correct transmission. A confirmation group is then identified by a set of related message identifiers Are defined. It can in a data bus multiple acknowledgment groups exist in parallel.

The method is described below by means of drawings described. This show in a schematic representation

1 several vectors used in connection with the method according to the invention and

2 an example of the coding of a confirmation vector as transmitted according to the invention with a message.

Several nodes, in particular control units, sensors or actuators, are combined to form a confirmation group. Each confirmation group can then have a group list 1 be assigned. The group list 1 is an ordered list of message identifiers and associated parameters. Each entry in the list consists, for example, of the information index, identifier, channels, direction, etc. The index indicates the position of the message identifier in the confirmation group. The identifier stands for the message identifier via which the status information is to be created. The information channels indicates which of the available channels should be included in the evaluation. The direction information indicates whether the identifier is a receive or a send message. The number of entries in the confirmation group list is called group size n. The message with the group index i is called group message GN _i .

Each node collects the status information about the correct receipt of messages for all group messages and stores these in the local status vector of the node. For each confirmation group, an acknowledgment group status vector (LSV) 2 be provided. The LSV 2 has the length n. The entry i in LSV indicates whether the message with the group index was last received correctly.

The channel information in the group list affects the formation of the LSV 2 If a correct message is received on one of the communication channels specified in the channel field, the corresponding entry in the Local Status Vector will be displayed 2 marked as correct. The LSV 2 is updated on the basis of the reception status information. A missing message is considered as incorrect reception.

Each message to be sent that belongs to a confirmation group will be sent with the confirmation vector 3 . 5 provided with a copy of the status vector LSV 2 having. A possible frame format for coding the confirmation vector 3 will be in the 2 shown. The sent local status vector 2 Confirmation vector BV is named in the message.

The local status vector 2 may be in the acknowledgment vector before transmitting 3 with the so-called application status vector (ASV) 4 be linked. As links, for example logical AND and logical OR links in question. In general, the link can be described as BV = f (ASV, LSV), where f is also the identical mapping of LSV 2 or ASV to BV.

Each node can act as a status vector 2 also a copy of a confirmation matrix 5 save. The confirmation matrix 5 consists of n rows and n columns.

The line i of the confirmation matrix 5 holds the received BV of the respective message with the group index i. The row i of the acknowledgment matrix is called external status vector (ESV _i ) of the group message i. When the group message i is received correctly, the ESV _{i is} overwritten with the BV from the message. Incorrect receipt of the group message i the entire ESV _i set incorrectly. If there is no reception, a) for static messages, the entire ESV _{i is set} to incorrect and maintained for b) dynamic messages of the ESV _i .

The columns of the acknowledgment matrix indicate the receive status of the group message j derived from all group messages. The column j of the confirmation matrix 5 is called Global Status Vector (GSV _j ) of the group message j. The GSV _j indicates which image the receiving nodes of all group messages have about the status of the special group message j.

While the external status vector thus the view of a single node over all Provides group messages, the global status vector provides the view all nodes over a single group message available.

The global status vector for send messages indicates which other group messages receive the broadcast message approved to have.

Is a priori knowledge of the Mapping of message identifiers to nodes available may be out the confirmation matrix Diagnostic information about Communication nodes are derived.

Each individual group message GN _i has an apriori defined acknowledgment cycle c _i . The acknowledgment cycle may be a round of communication or begin with the transmission slot of the group message GN _i and terminate the subsequent transmission slot of the same message. In the first case, the vectors and matrices must be buffered and consistently provided in the following round.

The global status vector changes with the receipt of each group message throughout the acknowledgment cycle. To provide an application with a stable and consolidated view of the status of a particular group message GN _j , the Global Status Vector is transferred to the Consolidated Status Vector (KSV _j ) at the end of the acknowledgment cycle.

The Local Status Vector can be through an AND / OR link or majority the received local status vectors are determined. The local Status vector on all channels can be identical. The local status vector can be channel specific or with several confirmation groups exist in parallel.

Claims (11)

Method for confirming a message transmission between nodes of a data bus system, in which particular messages a confirmation vector ( 3 . 5 ), the confirmation vector ( 3 . 5 ) is transmitted together with the message from one node to the next and in which the acknowledgment vector ( 3 . 5 ) indicates whether one or more previous messages have been transmitted correctly or incorrectly, with one status vector each ( 2 . 4 ) is provided in a plurality of nodes, in which information is stored for predetermined messages as to whether a message was received correctly or incorrectly, characterized in that, when a message is correctly transmitted, a region of the status vector ( 2 . 4 ) is overwritten in the receiving node, that in a message configured for this purpose, a copy of a status vector ( 2 . 4 ) of a node as a confirmation vector ( 3 . 5 ) is sent from at least one node to other nodes on the data bus and stored there; so that in each node, due to the status vector stored there ( 2 . 4 ), which messages were received correctly or incorrectly at the other nodes. Method for confirming a correct program execution or a correct system state in a data bus system, in which particular messages a confirmation vector ( 3 . 5 ), the confirmation vector ( 3 . 5 ) is transmitted together with the message from one node to the next and in which the acknowledgment vector ( 3 . 5 ) indicates whether a program execution or a system state has been correctly or incorrectly executed or achieved, wherein in each case a status vector ( 2 . 4 ) is provided in a plurality of nodes, in which part of a preceding acknowledgment vector ( 3 . 5 ) was stored, characterized in that when correctly executing a program or when a correct system state is reached, a region of the status vector ( 2 . 4 ) is overwritten in the receiving node, that in a message configured for this purpose, a copy of a status vector ( 2 . 4 ) of a node as acknowledgment vector ( 3 . 5 ) is sent by at least one node to other nodes on the data bus and stored there, so that in each node due to the status vector stored there ( 2 . 4 ) can be determined whether a program was executed correctly or a system state was reached correctly. Method according to claim 1 or 2, characterized in that the status vector ( 2 . 4 ) of a node cyclically with the copied status vectors ( 2 . 4 ) of the other nodes is overwritten. Method according to one of the preceding claims, characterized in that a plurality of nodes are combined to form a confirmation group and a confirmation group in each case a status vector ( 2 . 4 ) is assigned in a node, so that each node due to the evaluation of the status vector ( 2 . 4 ) can recognize which node of the acknowledgment group received a message correctly. Method according to one of the preceding claims, characterized in that certain messages are assigned to a confirmation group and in nodes of a confirmation group a local status vector ( 2 . 4 ) is stored per confirmation group, which confirms the correct reception of individual group messages. Method according to one of the preceding claims, characterized in that participants of the acknowledgment group receive a confirmation vector ( 3 . 5 ) send a message with a message. Method according to one of the preceding claims, characterized in that the acknowledgment vector ( 3 . 5 ) a copy of a status vector ( 2 . 4 ) and thus confirms the correct reception of individual messages from the confirmation group. Method according to one of the preceding claims, characterized in that in a confirmation vector ( 3 . 5 ) individual system states of programs, nodes or sensors / actuators are stored. Method according to one of the preceding claims, characterized in that a global status vector ( 2 . 4 ) the receive state from which provides the view of all the sender nodes of the single message acknowledgment group. Method according to one of the preceding claims, characterized in that an external status vector ( 2 . 4 ), which provides the view of a single send node of the acknowledgment group about all messages of the acknowledgment group. Method according to one of the preceding claims, characterized in that for each global status vector ( 2 . 4 ) a copy is provided at the end of a confirmation period.