DE19711958A1 - Network communication - Google Patents

Abstract

The invention relates to a method for communication in a network (NW), specially for communication in an electrical low voltage network, wherein a state interrogation is sent by a master (M1,2) to a plurality of slaves (Sn) in several network paths (Ln). According to the invention, a slave (Sn) that cannot be directly reached by the master (M1,2), e.g. an additionally installed slave (Sn), is included in the network (NW) by means of an adjacent slave (Sn), wherein said slave (Sn) is addressed as a router slave (R1, R2) for the slave (Sn) that cannot be directly reached . For this purpose, the network management software (NMS) of the master (M1,2) is provided with a software module (PLC') for the allocation of at least one router slave (R1, R2) to each slave (Sn). Each slave (Sn) also comprises a corresponding software module (PLC) to identify an adjacent slave (Sn) as a potential router slave (R1-R5).

Description

The invention relates to a method for network comm communication, especially for communication within a electrical low-voltage network, in which from a Ma most of a number of slaves in a number of network paths stretch a status query is sent (status pole ling) It also refers to such communica capable network.

In a communication-capable network, in which the commu application via strongly damped media with time-variant disturbances is usually adaptive and self learning communication software that is based on the Me mechanisms of a collision detection and / or collision ver avoidance based. Such mechanisms are however for the so-called PLC communication (PLC = Power Line Carrier) in unsuitable for an energy supply network since two end devices can send on different cables without hearing each other. Therefore, for PLC communication or transmission in Power supply network the use of a master-slave archi architecture preferred.

A communication-capable network with such a size The most slave architecture is e.g. B. from EP 0 598 297 A2 knows. The master sends a login over the network Deactivate (logon request) to everyone in the network ten devices (slaves), so that after receiving the response this newly installed slaves with the communication of the master these slaves can take place. Such a communication network enables the readout of Elek in particular Tricity counters and the automatic detection of an additional Lich counter or device connected to the network  without additional installation effort. It is always a disadvantage but that only slaves directly accessible from the master (Devices) identified and included in the network can.

The invention is therefore based on the object of a method for communication within a network with master Slave architecture and such a communication-capable Network to indicate that communication is also such Device with the master, which the master does not can receive directly. This process and this network in particular the inclusion of additional installed Devices in the network regardless of their distance to the Enable Masters.

With regard to the method, this object is achieved according to the invention solved by the features of claim 1. Everyone not directly accessible from the master, but only indirectly accessible Slave identified via a neighboring slave and into that Network added. The master can then only do that indirectly accessible slave via this, as a router slave query prioritized neighboring slave and its response receive.

This method is particularly suitable for the inclusion of new ones Devices and thus additional slaves in the network. Here is used by the newly installed slave during or in Connection to a status query of the Ma sters a number of neighboring slaves as router slaves (best neighbors) prioritized. The new slave will then be connected from the or each prioritized router slave at the Ma most logged on, one assigned to the newly installed slave assigned address in a corresponding register or in a Data table is included. In this data table also those router slaves and those network routes  or network routes, via which the additional instal gated slave according to the assigned reliability priority can be achieved.

After each status query of the master, the group the addresses of the Sla connected to the network ves in the data table regarding the network routes and the updated the router slaves via which the respective Slave is reachable. Each slave will have at least one Router slave assigned, including the address of the master be included in this routing table as a router address can. In this case the corresponding slave is from the master directly accessible.

Regarding the communication-capable network with a Ma ster and with a large number of slaves in a number of with network routes or network routes connected to the master the stated object achieved according to the invention by a network werk management software for assigning router slaves to the or each slave and to establish a connection between be neighboring slaves. The network management software serves furthermore advantageously also for the generation of Network routes, in particular replacement routes, between Ma ster and every slave.

The architecture of the network management software is based on the ISO communication protocol (ISO = International Standard disation organization), with the bottom three layers this communication protocol or model to guarantee router functionality within the network management ment software are implemented.

That in seven successive levels or protocol is a structured ISO communication protocol quasi-standardized model for the development of interfaces  len for the communication process within a communication tion network. The bottom, first layer (Physical Layer) the way of transmission of signals or individual bits from which z. B. modulation or Build up gain data. The second layer (Data Link Layer) specifies the procedures for securing an error-free Transmission on the individual network routes or network route sections of the systems (slaves) to avoid collisions. The third layer (network layer) ensures the correct one Structure of the individual sections between master (Sen the) and slave (receiver). The fourth layer (transport Layer) defines the function and the way in which the systems (masters, slaves) within the network or network should behave during the data transport. The un The four layers represent the transport protocol and are largely in the ISO commu systems today nication protocol defined.

The fifth layer (connection layer) sets the one details of the connection to be used Communication between the systems, i. H. between the master and the slaves and between the slaves. In the sixth The first layer (Presentation Layer) will be the one to be hit Agreements on the importance of exchanged data sets. In the top, seventh layer (application layer) are agreements on permissible applications between the communicating systems fixed. These three top Layers are also referred to as an application protocol, in which the agreements on those possible and admissible operations that are the master in the system of the slave. For the implementation of the router function is therefore advantageously only a data conversion within the three lowest layers of the ISO communication tion protocol required.  

In an expedient embodiment, the network management Software a (first) software module assigned to the master and a (second) software module assigned to each slave on. The master's software module is used for genius tion of at least one router slave for the or each slave. This software module preferably generates at least one additional network route or replacement route via which this Slave can be reached as an alternative. The software module of the Slaves is used to identify a neighboring slave. This software module generates a priority or Quality list of the best in terms of reception quality Neighbors ", via their software modules this list to Ma is forwarded.

The advantages achieved with the invention are in particular the other is that through the appropriate breakthrough of itself known master-slave architecture such that a master only indirectly accessible slave via a neighboring slave (Router) is added to the network, even new devices (Slaves) that cannot be received directly by the master NEN, in a simple manner without additional installation automatically built into a communication-capable network can be taken.

The method is particularly advantageous for communication cation within a low voltage electrical network kes, in which a data concentrator (master) for collecting ment and storage of meter data of a variety of elec Tricity counters (slaves) in a number of network routes these status queries are sent cyclically. In doing so Devices that are only indirectly accessible from the data concentrator the "best neighbors" (routers) added to the network.

An embodiment of the invention is based on a Drawing explained in more detail. In it show:  

Fig. 1 shows schematically a master-slave architecture, within a meshed communication-capable network

Fig. 2, the software architecture of a network management system for generating a router function within a network according to Fig. 1, and

Fig. 3, 4, the router functionality descriptive data Tabel len a master or a slave.

Fig. 1 shows the system architecture of a PLC subsystem (Power Line Carrier Subsystem) of a communication-capable network NW with the exemplary embodiment, two masters _1.2 M and a number of these communicatively connected via the mesh network NW slaves S _{S1. . .n} in three different distance levels E1, E2, E3 relative to the locations of the master M _1,2 . In the exemplary embodiment, it is a master-slave architecture within an energy supply network. The masters M _{1, 2} working on different channels are each assigned to a transformer station, not shown, while the slaves S _{1. .n} conventional electricity meters installed in households - hereinafter also referred to as devices - are.

Each master M _1,2 provides a data concentrator (Distribution Data Unit) for the devices or slaves S _{1. .n} represents. A network management software explained in more detail with reference to FIG. 2 directs connections from the respective master M _{1, 2} to the respective slaves S _{1. .n} a. Due to the meshed network topology, the masters M _1,2 must communicate on different channels in order to avoid mutual interference during data transmission. The manufacture of the connection of each slave S ₁ .. _.n to its master M ₁ or M ₂ can either directly or using a number of slaves S _{1. .n be manufactured} as a so-called "router". The meshing allows the connection of a slave S _n to different masters M _1,2 , wherein a slave S _{n can change} from one master M _1,2 to the other master M _2,1 during operation.

In the communication that usually takes place in master-slave mode, data collisions due to data transmission from different network points at the same time are avoided. The router functionality of the or each slave S _n described in more detail below also ensures that a response sent by a slave S _n as a result of a status query by the corresponding master M _{1, 2} from the other slaves S _{1. .n-1 is} received. As a result of this breakthrough of the usual master-slave mechanism, automatic recording and automatic network path assignment (routing) as additional functions are avoided as a function of a so-called "logon request", even for such slaves S _{1. .n} realized that do not have direct access to one of the M _1.2 masters. This is particularly important for the installation of new, additional devices in the network, since following their installation they do not yet have a logical connection to one of the masters M _1,2 and therefore neither identified nor em by them at this point in time can be caught. In the exemplary embodiment, this applies to the slaves S ₆ arranged in the distance planes E2 and E3 or newly installed there _{. .10} or S _{11 .. .n} .

To implement this additional router functionality, each slave S _{n has} a software module PLC and each master M _{1,2 has} a software module PLC '. The software module PLC of each slave S _n is connected to a connection line L _n led to the corresponding device for power transmission including the entire network functionality. The bottom three layers of the ISO communication protocol are implemented in this software module PLC of each slave S _n to implement the router functionality. The layers of the ISO communication protocol lying there are implemented in an application module MA (Meter Applications) of the corresponding slave S _n . The functionality of this application module MA is independent of the functionality of the software module PLC, so that every network management function runs through these software modules PLC.

Each master M 1, ₂ has a data concentrator DC and a first communication module KM1, which only works at the master level, and a second communication module KM2 for communication that is functionally independent of the software module PLC '. The PLC 'software module is also integrated in the master functionality.

The architecture of a network management software implemented in the software module PLC of the or each slave S _n and in the software module PLC 'of the or each master M _1,2 is shown schematically in FIG. 2. The implementation of the network management software NMS and a tabular network database or data table DT is shown within the layers of the ISO communication protocol. The network management software NMS uses the third layer or network level NL (network layer) to set the course for data transport either to the next higher layers up to the application level AL (application layer) or to the next lower, the data transport or layer of the ISO communication protocol representing data link level DL (Data Link Layer). The data table DT also accesses the network level NL, which in turn is accessed by the network management software NMS. The network level NL is transparent to the layers above.

The network level NL requires network information data in order to send inquiries or information to the slaves _1. Each addressed as router slaves _{. .n} to transfer. The functions of the network level NL are therefore always the same for the master M _1,2 and for each slave S _n , while the network data and thus the data tables DT and the network management software NMS of the master M _1,2 or the slave S _{n are} different. The data link level DL (data link layer) lying between the network level NL and the physical level PL (physical layer) is also transparent for the network management software NMS. Within this data link level DL, in which the functionality of a collision detection and / or collision avoidance can be implemented, point-to-point connections between the slaves S _1. Are made without any master-slave structure _{. .n} manufactured or "broadcasts" sent.

The software architecture shown in FIG. 2 applies both to the software module PLC 'of the master M _1,2 and to the software module PLC of the slave S _n . Only the functionalities of the network management software NMS and the content and form of the data table DT are different for the master M _1,2 and for the slave S _n , while the respective structure is identical. Therefore, reference is subsequently made to the network management software NMS _{M of} the master M _{1, 2} or the network management software NMS _{S of} the slave S _n by appropriate indexing. Regarding the software module PLC 'of the master M _1,2 , the network level NL serves for data acquisition from the higher levels TL, AL or from the network management software NNS _M and for the transmission of this data to the data transport level DL.

The data table DT _M created by the software module PLC 'of the master M _1,2 is shown in FIG. 3. The frame of the corresponding data connection level DL _{M contains} an address (device address) of the respective slave S _n (meter), which is converted into a network address (network layer address) using the upper list in FIG. 3 (logon list). In addition, the frame of the data link level DL _{M contains} a number of fields for z. B. a first and a second router slave. These fields are based on the lower in Fig. 3 (routing list) with a route to the respective router slave R1, R2, the best in terms of reliable availability of an adjacent slave S _n best router slave based on a quality Codes are prioritized. The addresses listed, running from 0001h to 7FEFh, are selected in a playful manner, the address 7FFFh identifying an unused router slave R1, R2.

The master M _1,2 groups the slaves S _n connected to it and listed in the "logon list" based on their router slaves R1, R2 and creates this list as a network data table DT _M , which is updated cyclically. In this way, by means of the software module PLC 'of the master M _1,2, each slave S _n is assigned two router slaves R1 and R2 in three network routes or network routes L _n (route nos. 1,2 and 3).

Similarly, each slave S _n uses the software module PLC to generate a network data table DT _S shown in FIG. 4. In the lower list in FIG. 4 (logon request list) of the data table le D _S , the addresses of those router slaves R1, R2, R3 are entered on the one hand, via which this slave S _n can be reached. For this purpose, the slave S _n first collects in the upper list in FIG. 4 (best router list) the addresses (addr. No. 1, 2, 3) of the slaves S _n received by the latter via possible communication paths (routes), which are not already have been addressed by two router slaves R1, R2. These addresses are within a predeterminable time frame T of z. B. 15 minutes before the slave S _n informs the master M _{1,2 of} the first three addresses of the "best neighbors" via the router slaves R1, R2 belonging to these addresses as part of a cyclic status query. The time frames T _Z , ie the waiting times, are subject to an aging process so that more recent results are taken into account more.

Thus, an additionally installed device via its software module PLC can first collect addresses of slaves S _n identified as possible router slaves R1 to R5 during a status query of the associated master M _1,2 and prioritize them in terms of their respective accessibility. This slave S _n then transmits the addresses of the prioritized router slaves R1 to R3 via these router slaves R1 to R3 to the corresponding master M _1,2 . Its software module PLC 'makes a corresponding entry in its network data table DT _M. Subsequently, the master M causes the additionally receive _1.2 the highest priority slave router R1 in stallierten slave S via the corresponding route (route no. 1) in the network NW. The other reported router slaves R1, R2 of the other routes (route nos. 2 and 3) are then routed according to their priority (quality) as replacement routes. The software module PLC of each slave S _n thus serves to identify both an adjacent slave S _n , e.g. B. a newly installed slave S _n , as well as at least one neighboring slave S _n as future router ter slave R1, R2.

The network management software NMS - implemented in the software modules PLC, PLC '- thus enables each master M _1,2 to assign three communication paths (routes) to each slave S _{n in the} exemplary embodiment. The corresponding data table DT _M , which in addition to these routes or network routes L _n also includes the router slaves R1, R2 assigned to each slave S _n , is preferably updated dynamically. In addition, the network management software NMS enables each newly installed slave S _{n and} its neighboring slaves S _1. to receive _.n-1 and to report to the NW network via the "best neighbors" - that is to say quasi yourself.

In this way, newly installed devices (slaves) can be added to the network NW regardless of their distance from the data concentrator DC (master) without additional installation effort. Here are z. B. for slaves S _{n of} the third distance level E3, two routing slaves R1, R2 are listed in the data table DT, while only one router slave R1 is listed for those of the second distance level E2. In the case of slaves S _{n of} the first distance level E1 received directly from the master M _1,2 , the master M _1,2 itself is registered as a router slave R1.

Claims (12)

1. Method for communication within a network (NW), in particular for communication within an electrical low-voltage network, in which from a master (M _1,2 ) to a plurality of slaves (S _{1.. .N} ) in a number of network routes (L _n ) a status request is sent, characterized in that a slave (S _n ) indirectly reachable by the master (M _1,2 ) via an adjacent slave (S ₁ ...) Identified as a router slave (R1, R2) _{. n-1} ) is included in the network (NW). 2. The method according to claim 1, characterized in that a subsequent status query of the master (M _1,2 ) on the router slave (R1, R2) to the indirectly accessible slave (S _n ) is forwarded. 3. The method according to claim 1 or 2, characterized in that the router slave (R1, R2) is addressed by the master (M _1,2 ) for querying the indirectly reachable slave (S _n ). 4. The method according to any one of claims 1 to 3, characterized in that each slave (S _n ) is assigned at least one router slave (R1, R2), with each slave being cyclically queried with regard to its router slave (R1, R2) , and wherein the address of this slave (S _n ) is assigned a corresponding address of the or each router slave (R1, R2). 5. The method according to any one of claims 1 to 4, characterized in that a number of adjacent slaves (S _n ) is prioritized as router slaves (R1, R2), where at from an additionally installed and indirectly accessible slave towards its reachability the additionally installed slave (S _n ) is added to the network with the highest priority via the router slave (R1, R2). 6. The method according to claim 5, characterized in

• - that during the status query of the additionally installed slave (S _n ) network addresses of a number of neighboring slaves (S _{1.. .n-1} ) are first stored,
• - that the additionally installed slave (S _n ) is registered with the master (M _1,2 ) via at least one of the neighboring slaves (S _{1. .n-1} ), and
• - That the additionally installed slave (S _n ) from the master (M _1,2 ) is assigned the network address of the or each router slave (R1, R2).

7. The method according to claim 5 or 6, characterized in that the additional Lich installed slave (S _n ) from the master (M _1,2 ) is assigned a network address. 8. Communication-capable network with a master and with a large number of slaves (S _n ) in a number of network routes (L _n ) connected to the master (M _1,2 ), the master being designed to query the status of each slave (S _n ) , characterized by a network management software (NMS) for assigning router slaves (R1, R2) to the or each slave (S _n ) and for establishing a connection between neighboring slaves (S _n ). 9. Communication-capable network according to claim 8, characterized in that the network management software (NMS) is assigned to the master (M _1,2 ) software module (PLC ') for generating at least one router slave (R1, R2) for the or each slave (S _n ) and a software module (PLC) assigned to the or each slave (S _n ) for identifying an adjacent slave (S _n ). 10. Communication-capable network according to claim 9, characterized in that the software module (PLC ') of the master (M _1,2 ) is designed to generate at least one replacement route (L _n ). 11. Communication network according to claim 9 or 10, characterized in that the software module (PLC ') of the master (M _1,2 ) for assigning a network address to an additionally installed slave (S _n ) is laid out. 12. Communication network according to one of claims 8 to 11, characterized in that the software module (PLC) of the slave (S _n ) for generating a list of priorities with network addresses of adjacent slaves (S _{1.. .N} ) and for forwarding such a list created by an adjacent slave (S _n ) is designed for the master (M _1,2 ).