DE102009045127A1 - Method for assignment of identifier at bus system-switched units for communication in rail vehicle, involves generating assignment identifier by each layer determining unit in connection with layer relative to layer regard location - Google Patents

Abstract

The position regarding the layer regard location is determined. Each layer determining unit (11) in connection with the layer relative to the layer regard location is turned on at the CAN bus system (14) to generate the assignment identifier and to execute communication with the assignment identifier over the bus system.

Description

The present invention relates to a method for assigning identifiers to bus-system-connected units.

The communications between Bussystemgeschalteten units is based on general communication principles. From the prior art address communication principle and message identifier communication principle are known.

In the address communication principle, each bus-switched unit is assigned a one-to-one address. In general, the assignment of an address is done manually on the one hand by direct Adressbeschaltung the unit with z. B. DIL switch or the other by the unique step-by-step application of address data per unit. In the latter variant, the unit is either not yet connected in the communication network or it is selected by a programming switch to load the address.

In the DE 10 2004 041 092 A1 A method of assigning a device address to a slave station in a network is disclosed. Each substation has a set communication address. A master station sends to the slave station an initialization telegram with part of the device address.

The DE 10 2006 018 163 B4 discloses a method for automatically assigning addresses to communication users located in rail vehicles. Each communication user determines in a first step identifiers of the immediately adjacent communication participants. In a further step, the determined data is sent to a higher-level unit, which recognizes neighborhood relationships between the communication participants on the basis of the transmitted data. With this realization, the address assignment takes place.

The message identifier communication principle comes z. In the Controller Area Network ( CAN / ISO 11898 ) is usually used. The special feature of this communication principle is that an identifier (ID) is not assigned to the unit but to a message. This has the advantage that the ID characterizes the functional property of the message at the same time. From the prior art known, the ID assignment takes place manually due to the functional message-oriented assignment of IDs. This has the disadvantage that the effort is particularly high, especially with changed expansion variants. Therefore, in order to reduce the effort in turn, the IDs are assigned to the devices over which the communications are then carried out. The advantage of message-oriented communication is thus lost.

The object of the invention is to provide a method for assigning identifiers to bussystemgeschalteten units, in which the allocation of the identifier regardless of the location of the connection of a unit to the bus system and regardless of the type of powered unit automatically, easily and without much effort he follows.

According to the invention the object is achieved by the features mentioned in claim 1. Advantageous embodiments of the invention will become apparent from the features of the dependent claims.

In a method according to the invention, the assignment of the identifier takes place independently of the location of the connection of a unit to the bus system and regardless of the type of unit connected automatically, easily and without much effort. In order to assign identifiers to each unit connected to the bus system, which is to carry out future communication via the bus system, at least one position determination with respect to at least one position reference location is carried out in a first step. Each connected to the bus system determining unit generates in connection with their location to the location reference location or with their locations to Lagebezugsorten at least one allocation identifier and performs with the allocation identifier communications via the bus system for the allocation of identifiers.

The invention will be described below by way of example with reference to FIGS 1 and 2 illustrated embodiments illustrated. Showing:

1 a blockschatbild a first embodiment variant for the automatic assignment of identifiers, and

2 : A block diagram of a second embodiment variant for the automatic assignment of identifiers.

In the 1 a CAN bus system is shown 14 with identically designed bus-connected units E1, their principally illustrated high-speed bus couplings ISO 11898 and the LA characteristic resistances. Each bus-connected unit E1 contains next to a CAN controller 12 with integrated CAN bus interface a position determining unit 11 , The location determining units 11 the bus-switched units E1 are on the input and output side over in full duplex mode designed lines 13 connected with each other. The input I1 or I2 of the position determining unit 11 one between those at the bus ends connected units E1 is connected to the output A1 or A2 position determining unit 11 connected to the preceding bus-connected unit E1.

In 2 is also a CAN bus system 14 with identically designed bus-connected units E2, their principally illustrated high-speed bus couplings ISO 11898 and the LA characteristic resistances. The variant in the 2 differs from the variant in 1 only in that the location determining units 11 the bus-connected units E2 and their CAN controller each to a unit 2 are summarized.

During start-up (switching on of the operating voltage) of all units E1 or E2 connected to the bus system, all outputs A1 and A2 are switched active. Each location determining unit 11 Checks at their inputs I1 and I2 for the presence of active position of recognizing signals. If an inactive position recognizes a signal at one of the inputs I1 or I2, then the unit E1 or E2 recognizes itself as a unit connected to the bus end. If active-position-detecting signals are present at both inputs I1 and I2, the unit E1 or E2 recognizes itself as a unit located in the center position.

In the exemplary embodiments selected, the units E1 or E2 connected to the bus ends are defined as position reference locations. The units E1 or E2 connected to the bus ends each generate a count value 1 and send it to the output A1 or A2, to whose assigned input I1 or I2 an inactive position was detected. Each unit E1 or E2 connected to the bus system, the position-determining unit of which receives a count value, preferably changes the count value by one or another predetermined increment and sends this changed count value to the subsequent unit E1 or E2. With at least one received count value coming from a bus end or one count count received from a bus end, each unit generates its assignment identifier. With this assignment identifier, the unit E1 or E2 initiates the telegram arbitration in the CAN data frame after detection of the idle bus state on the CAN bus lines. In the data field of the data frame, the unit E1 or E2 transmits an identifier for identifying the respective unit E1 or E2. A bus-connected unit E1 or E2 is designed as an identifier assignment unit. It is used to assign all identifiers for the future communications between the bus-connected units E1 or E2. Using the identifiers for identifying a unit E1 or E2, the unit E1 or E2 specified for identifying the identifier selects the assigned identifier of the unit issuing the identifier and sends it with at least one data frame via the CAN bus to the corresponding allocation Identifier connected unit. After all units E1 or E2 have received their assigned identifier, the identifier assignment unit sends to all bus-switched units E1 or E2 a data frame with an identifier specified for identifying the completion of the identifier assignment. The identifier specified for identifying the completion of the identifier assignment is an identifier known to all bus-connected units, which is taken from the pool of all identifiers of future communications and differs from the assignment identifier.

Upon receipt of the completion of the identifier assignment, the assignment identifiers become inactive. Preferably, there exists a second identifier taken from the pool of all identifiers of the future communications. This identifier indicates the renewed transition to the identifier assignment mode, so that there is a dynamic change in the expansion of the communication system.

For determining a reference location of a lying within a central situation unit E1 or E2 have the situation detecting units 11 an additional programmable, in the 1 and 2 not shown input for determining the position reference location.

The advantages of the inventive solution are that the method for assigning identifier to bussystemgeschalteten units automatically assigns the identifier regardless of the location of the connection of a unit to the bus system and regardless of the type of powered unit, and without much effort.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102004041092 A1 [0004]
• DE 102006018163 B4 [0005]

Cited non-patent literature

• CAN / ISO 11898 [0006]
• ISO 11898 [0013]
• ISO 11898 [0014]

Claims (7)

Method for assigning identifiers to bus-system-connected units, characterized in that - for automatically assigning identifiers, each unit connected to the bus system, which will in the future perform communication via the bus system, executes at least one attitude determination with respect to at least one location reference location, and each connected to the bus system determining unit in conjunction with their position relative to the location reference location or with their locations to Lagebezugsorten at least one assignment identifier generated and executes communications with him via the bus system for the automatic assignment of identifiers. A method according to claim 1, characterized in that the position determinations are carried out using position-detecting signals, wherein the position of a device connected to the bus end unit by at least one inactive position recognizing signal and the center of a unit connected to the bus end unit through active Location recognizing signals are detected. Method according to claim 1 or 2, characterized That the position determining unit at the reference location generates at least one count value and sends it to the preceding or subsequent position determining unit or to the preceding and subsequent position determining unit, - That all connected to the bus system position determining units that receive a count, change this count by a predetermined increment or decrement and forward it, or - That each connected to the bus system determining unit that receives more than one count, every count or only one count by a predetermined increment or decrement value changes and retransmits, and - That each connected to the bus system determining unit from at least one of the counts generates their assignment identifier. Method according to at least one of the preceding claims, characterized in that the position reference location lies in a position-determining unit at the bus end or in that the position reference locations are located in both position-determining units connected to the bus ends or in that the position reference location is in one between the bus ends connected location determining unit is located. Method according to at least one of the preceding claims, characterized in that the count value in the position determined at the location reference location of the bus end determining unit is the smallest or largest possible count. Method according to one of Claims 1, 3 or 4, characterized in that, at a position reference location on a position connected between the bus ends, the unit has the largest possible and smallest possible count value, one count value each determining the preceding position and the subsequent position Unit is sent. Method according to one of claims 1 to 6, characterized in that in the communication with the assignment identifier, a unit identifier is exchanged, which indicates to the identifier assignment unit the type of unit with which the identifier assignment unit the desired assignment of the identifier for future communication.

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