The invention relates to a device for transmitting, exchanging, and/or forwarding data and/or information in the context of industrial process- and/or automation technology.
From the state of the art, it is known to have sensors or transmitters communicating via a bus system digitally with one another, and/or with a remote control station. Prerequisite for smooth communication is, on one hand, continuous availability, and, on the other hand, an adequately large capacity, of the data line which is used in the bus system. The data line is normally a two- or multi-strand cable. If the data line fails for any reason, or if its capacity is exhausted, then this leads to the fact that an efficient and timely data transfer, for example, the transfer of a measured value, can no longer take place. If one considers the case that, depending on the measured value to be transmitted, a safety valve is to be opened or closed, then it goes without saying that conventional bus systems cannot, without further measures, adequately accommodate the high safety demands in the fields of process- and automation technology.
An object of the invention is to provide a device which permits a redundant communication without overloading the data line.
The object is achieved by having a first unit and at least a second unit communicate with each other, with one unit being a transmitter or sensor, which supplies a measured value for determining a physical or chemical parameter. The at least two units belong to a combined assembly, or network, of a plurality of units, which, either directly, or indirectly via at least one intermediate unit, communicate with one another, with each of the units having at least two physical communication interfaces, and with at least one microprocessor being assigned to each unit.
In principle, the device of the invention uses a multiple networking of the sensors and/or transmitters—analogous to an interconnected group of computers, which forward data and/or information via the Internet. Through this, it is possible to optimally load the data lines to their full capacities. Even in the case of the transfer of large amounts of data, relatively small transfer times can be achieved, since, for example, the data can be sent in parallel along different paths to the addressee.
Furthermore, a redundant data communication is possible, because normally a sensor or transmitter can exchange data and information with another sensor or transmitter via a plurality of different paths. Consequently, it is possible that the individual units communicate with one another, without the entire bus system always becoming too heavily loaded.
In particular, this enables the use of small band widths for the transfer of data and/or information, which, in turn, is reflected in an increased resistance to interference. Incidentally, this is especially advantageous when the units, sensors, or transmitters, are used in areas where there is danger of explosion. Here, the use of small band widths for the transfer of data is widespread.
In accordance with a further development of the device of the invention, the transmitter or sensor can be a fill level measuring device, a pressure transmitter, a flow rate sensor, a temperature sensor, or an analytical device. The assignee, or enterprises associated with the assignee, as the case may be, distribute a wide variety of sensors and transmitters for determining and/or monitoring physical and/or chemical variables. In principle, a units used in the device of the invention naturally need not be a transmitter or sensor. The term “unit” can describe any unit having at least two physical communication interfaces and a microprocessor. Thus, naturally, a unit can also be a communications unit, a router, an evaluation/control unit, a parametering unit, or an actuator.
It is considered an especially favorable embodiment of the device of the invention that, in the microprocessor of a first unit, which transmits data and/or information to at least a second unit, information concerning the topology of the network is contained, and that preferably this information concerning the topology is transmitted with the data and/or information. In effect, the data and/or information to be transmitted is accompanied by information concerning the path by which it can get to the respectively addressed unit—in the following, the respective addressee—the fastest.
In order to ensure that the data and/or other information reaches the desired addressee, it is alternatively provided that, in the microprocessors, in at least one part of the units, the information concerning the topology of the network is saved, so that, on the basis of the addressee to which the data and/or information is to be sent, the corresponding unit recognizes the path, or alternative path, along which the data and/or information must be sent, or forwarded, as the case may be.
In accordance with a further embodiment of the device of invention, it is provided that a unit determines the topology of the network via communication with the neighboring unit or units, stores the acquired information in a memory unit, and thus recognizes along which path, or alternative paths, it preferably sends, or forwards, as the case may be, the data and/or information.
For the purpose of selecting optimal communication paths, it is provided that a unit determines, once, sporadically, or cyclically, the capacity of a communication path to the different units communicating with it directly or indirectly, and stores the individual communication paths with differentiated classification in an assigned memory unit.
A further alternative embodiment for reaching the respective addressee is the trial/error variant: a unit forwards the data and/or information to at least any one unit; the respective unit receiving the data and/or information forwards the data and/or information in the same manner until the data and information reaches the unit to which the data and/or information are addressed. In the case of this variant, in order to avoid that the data lines become overburdened, a unit only forwards the data and/or information as long as a predetermined number of forwardings is not yet attained.
In order to ensure that important information is transmitted chronologically before less important information, the units transfer the data and/or information on the basis of predetermined priority criteria.
In accordance with a preferred embodiment of the device of the invention, in the case of a large amount of data and/or information to be transferred, a unit selects multiple, mutually independent communication paths in order to transfer the data and/or information in parallel. This embodiment allows even large amounts of data to be quickly transmitted to the respective addressee.
An advantageous development of the device of the invention provides converters, which are assigned to the units, such that the units can communicate with one another via different types of transmission. These converters can also be sensors which support different types of transmission at the various interfaces.
In accordance with an advantageous development of the device of the invention, either connecting cables or fiber optic cables, or ways of so-called wireless data- and/or information transfer are used as ways of communication.
The invention will now be described in greater detail on the basis of the drawings, the figures of which show as follows:
In
In the case of the network 2 of the invention shown in
Shown in
So that the data and/or information arrive at the designated addressee, some variants of embodiments will now be described as follows, as to how the information preferably is obtained, or conveyed, as the case may be, over the communication paths:
A unit A, B, C, D, E, F knows the topology of the network 2, and understands along which communication path 3, or along which alternative communication path 3, the data and/or information must be transferred in order to arrive at the desired addressee. This information concerning the topology of the network 2 accompanies the traveling data and/or information.
The topology is, for example, stored in the memory unit 7 of a unit A, B, C, D, E, F. On the basis of the address at which the data and/or information should arrive, each unit A, B, C, D, E, F knows along which communication path 3, or along which alternative communication path 3, it must forward the data and/or information.
Through trial/error processes, a unit A, B, C, D, E, F determines the topology of the network 2 by sending the data and/or information to each of the neighboring units. For example, this process is repeated until the data and/or information have reached the desired addressee. The information, acquired in this way, concerning the topology of the network 2 is stored in the memory units 7 of the units A, B, C, D, E, F. Thus, at the same time, the capability (loading, speed) of a communication path 3 can be tested and stored. It can also be provided that the data and/or information is no longer forwarded as soon as a maximum predetermined number of failed attempts is reached, or, as soon as the data and/or information have exceeded a certain age, as the case may be.
Likewise is it possible that the data and/or information are given priorities, with, in each case, the data and/or information with the highest priority being forwarded preferentially along the short and quick communication paths 3.
Furthermore, the communication paths 3 can, as a result of the multiple networking, be optimally used. If, for example, the load between the units A, B is very high, then the data and/or information can nevertheless quickly reach the desired addressee B via the communication paths 3 between A and C, and C and B. Given that a conventional bus system 1, which becomes loaded as a result of the communication between two units, is no longer present, significantly smaller bandwidths, which are consequently more resistant to interference, can be used for the digital communication. Additionally, small bandwidths prove to be especially advantageous when the units A, B, C, D, E, F are implemented in areas where there is danger of explosion. As mentioned already above, the use of different types of transmission in a network 2 causes no problems.
An optimizing of the communication in the network 2 of the invention can be attained by providing the data and/or information to be transferred with a priority label. In
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP02/09191 | 8/16/2002 | WO | 9/12/2005 |