SYSTEM, DEVICE AND METHOD FOR SUPERVISION OF OBJECTS

Abstract: An object supervision system comprising at least one superior supervising means (28) and a device for supervising objects (30, 32, 34, 36, 38, 40, 42, 44) and/or flows of information. The device comprises at least two agent units (10, 12, 14, 16, 18, 20, 22, 24) that are interconnected in a network (26) and transmit messages to the superior supervising means, either upon request or on their own initiative, concerning objects connected thereto. At least one agent unit includes at least one supervising port for connection to an object. A group access port (46) is common to all agent units in the device and is connected to the superior supervising means for communication between the supervising means and the agent units.

Description: SYSTEM, DEVICE AND METHOD FOR SUPERVISION OF OBJECTS FIELD OF INVENTION The present invention relates to the field of object supervision, and more particularly to a device that includes at least two agent units and functions to supervise objects and/or information flows, an object supervising system that includes one such device, and also relates to methods of transmitting messages between a group of agent units and at least one superior supervising means . DESCRIPTION OF THE BACKGROUND ART Object supervising systems are well known to the art. One such known system includes a superior supervising means, normally called manager or system manager, that is connected to and supervises several agent units, each of which in turn supervises at least one object or a flow of information through an object. This type of supervising system is beneficial when a superior supervising means is used to supervise many objects. The use of agent units lightens the load on the superior supervising means. One such system is described in EP-A2-0 621 706, for instance. The agent units are normally connected to a superior supervising means in some form of network, such that each agent unit will have its own connection point to the superior supervising means. One such coupling is disclosed in GB-A-2 243 748 for instance, in which an agent unit is designated NFI and the superior supervising means is designated host processor. When wishing to reduce the number of conductors between agent units and a superior supervising means in a supervising system, which is of particular interest when the agent units are located far from the superior supervising means, there is required to this end a hub or router or some corresponding means . GB-A-2 128 388 discloses a supervising system in which a superior supervising means, designated master station, is connected to a plurality of substations that are each connected in turn to at least one interface module . Several interface modules may be connected to a substation through the medium of a serial data bus. In the present context, the substations correspond closest to agent units that supervise an object through the medium of an interface module. An interface module may also be connected directly to the master station, and it is said that the master station will then function as a substation. The publication does not, however, disclose that the interface modules shall function as substations when they are connected to the master station through the medium of a substation. DISCLOSURE OF THE INVENTION The invention solves the problem of reducing the number of connections between a group of agents and a superior supervising means in a simple manner, without the use of additional interlinking devices. This problem has been solved by virtue of the agent units in the group communicating with the superior supervising means through the medium of a common group access port, such that the group has only one access point . The object of the invention is to provide an object supervising device that includes at least two agent units, a supervising system that includes at least one such device, and a method of transmitting messages between one group of agent units and at least one superior supervising means, wherein the connection and communication between at least one superior supervising means and a group of agent units is effected through the medium of one single group connection point . This object is achieved with a device and a system that includes one such device wherein at least two agent units that supervise objects and/or information flows are interconnected in a network and communicate with superior supervising means. At least one of the agent units includes at least one supervising port for connection to an object. All agent units in the device have a common group access port for connection to at least one superior supervising means . This object is achieved by a method in which the agent units transfer to the superior supervising means messages that concern objects that are connected to said agent units, through the medium of an access port that is common to said group. A further object is to provide a system that is more flexible with respect to communication paths. This object is achieved by virtue of the agent units being able to communicate with one another in addition to communicating with the superior supervising means. A further object is to provide a device and a method that will lighten the work load of a superior supervising means. This object is achieved with a device and a method wherewith a first of the agent units reads the messages sent by other agent units in the device/group and supervises and controls said other agent units, and which itself sends to the superior supervising means messages that concern said other agent units, either on its own initiative or upon request. Yet another object of the invention is to provide a system that enables "old" equipment to be used in the supervising system. This object is achieved by virtue of the fact that in addition to at least one of the agent units converting operational information received from an object and including a first object specific protocol into one or more messages that includes/include a supervising specific second protocol and that is/are sent to a superior supervising means, said at least one agent unit also sends this operational information which includes said first protocol to at least one superior supervising means. Yet another object is to provide a magazine in which the device can be implemented. This object is achieved by virtue of a magazine that has a backplane bus that includes the network. The present invention provides the advantage of obtaining a simple device that includes a number of agent units that have simple communication paths, therewith avoiding the use of unnecessary interlinking components or circuits between the agent units and at least one superior supervising means. The invention also has the advantage of reducing the number of lines required in the system. Another advantage is that all agent units in the device can be supplied from one and the same voltage source. BRIEF DESCRIPTION OF THE DRAWINGS Further advantages and objects of the invention will become apparent from the following description of different embodiments of the invention, said description being made with reference to the accompanying drawings, in which Fig. 1 illustrates an inventive supervising system; Fig. 2 illustrates schematically the structure of messages that are sent in an inventive system; Fig. 3 is a flowchart that describes a method of sending messages intended for an inventive device; and Fig. 4 is a flowchart that describes a method of receiving messages in an inventive device. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Fig. 1 is a schematic illustration of an inventive supervising system. The illustrated supervising system includes a group of eight agent units or subordinate supervising units 10, 12, 14, 16, 18, 20, 22 and 24 that are interlinked in a network 26 through the medium of a respective network port. In the case of the illustrated embodiment, the network 26 is a token ring network, although it may alternatively have the form of a bus, for instance some type of ethernet. Each agent unit 10, 12, 14, 16, 18, 20, 22 and 24 includes a supervising port to which respective objects 30, 32, 34, 36, 38, 40, 42 and 44 supervised by said units are connected. These objects may possibly be located at a relatively long distance from the agent units . The agent units are proxy agents that forward information from the object and are free-standing in relation thereto. A first of the agent units 10 also includes a group access port 46 by means of which it is connected to a superior supervising means 28, often referred to as manager or management platform, through the medium of a transmission link 48. The superior supervising means 28 will often include a terminal and a personal computer such that persons engaged in supervising the objects are able to see the operational status of these objects if necessary. The objects 30, 32, 34, 36, 38, 40, 42 and 44 may be different sorts of devices that perform mutually different functions. For instance, a first object 30 may be a burglar alarm system, a second object 32 may be a telephone exchange or switching centre, a third object 34 may include one or two network interfaces, such as a token ring for instance, a fourth object 36 may include one or two interfaces in a network, such as an ethernet for instance, a fifth object 38 may be a broadband telephone exchange, and a sixth object 40 may be a refrigerating or cooling system. The objects may also comprise a plurality of different network elements in one single network. The reason why the third object 34 may include two interfaces that are connected to one and the same agent unit is to provide redundancy. All of the different objects 30, 32, 34, 36, 38, 40, 42 and 44 communicate with respective agent units 10, 12, 14, 16, 18, 20, 22 and 24 in accordance with different protocols that are specific to the different types of objects concerned. For instance, the telephone exchange 32 may require the second agent unit 12 to be a special agent unit that uses a protocol that is specific to this telephone exchange, which may be MML, for instance. The third and the fourth objects 34 and 36 require a network specialised agent unit, for instance some type of RMON agent unit that uses a protocol specific to corresponding interf ces. Similarly, broadband equipment require ATM agent units that utilize special broadband protocols . Each agent unit includes a microprocessor and a memory and is operable for controlling and supervising the object connected thereto. Each agent unit communicates with its object with the special protocol required by said object and receives operational information that includes this special protocol, and converts this information into at least one message that includes a supervising specific protocol and that is transmitted to a superior supervising means. The supervising specific protocol is SNMP or CMIP for instance, and is common to all agent units and to at least one superior supervising means. An agent unit senses the operational status of the object connected thereto, by reading ports, which can be done on the initiative of the agent unit or upon request by the superior supervising means 28, and controls the object through the medium of different types of control functions. The messages may also be transmitted from the agent unit upon request or on its own initiative, i.e. independently. The agent units may also be adapted to send messages that include data other than the converted operational information, for instance such data as alarm data, data requesting the transmission of messages that include operational information, and so on. The agent units may also be adapted to analyze operational information received from an object and to process this information, for instance reduce the information to a single error or fault message when several error or fault messages are received and which are all the result of a single error or fault message. The agent units may also be adapted to send messages to each other. This facility may be useful when using two agent units in a redundant coupling. A redundant coupling may, for instance, include two agent units that are connected to one another and to one and the same object, wherewith the messages may then be sent on the network 26 from one agent unit to the other if the second agent unit is to take over control of the object from the first mentioned agent unit. All communication between the superior supervising means 28 and the agent units takes place through the medium of the first agent unit 10, therewith obviating the use of unnecessarily long conductors or other equipment between the superior supervising means 28 and the agent units in the group. Thus, the superior supervising means 28 polls connected agent units in accordance with some predetermined procedure and issues to the agent units commands that have bearing on the responses that are received in conjunction with the poll. As before mentioned, the agent units 10, 12, 14, 16, 18, 20, 22 and 24 also send independent messages to the superior supervising means 28, which may include some form of interruption routine for handling such messages. The superior supervising means 28 may be manned to handle diverse alarm situations. The use of agent units to supervise objects relieves the load on the superior supervising means 28, which perhaps is intended to supervise many other object-supervising agent units outside the group. The superior supervising means 28 may be located far from the group of agent units and a significant saving is therewith made in the number of transmission links between the group of agent units and the superior supervising means 28, which is particularly beneficial when the link 48 is in the form of a fixed line. Alternatively, the link 48 may consist of the public switched telephone network, in which case a significant saving is made in the number of modems required, or some other communications network, radio communications network, in which case a significant saving in transceivers is made, and so on. Furthermore, the use of an interlinking device between the agent units and the superior supervising means, for instance a hub or a router, is avoided. The illustrated system can be varied in many ways. For instance, the group access port 46 may be provided on an agent unit other than the first agent unit 10, and two agent units may be connected to one and the same object. As before mentioned, the link 48 between the superior supervising means 28 and the group of agent units may vary. However, when the public switched telephone network is used without an integrated services digital network, ISDN, it is necessary to connect at least one modem between the group access port 46 of the first agent unit 10 and the transmission link 48. Furthermore, several different superior supervising means may be connected to the group of agent units instead of only one superior supervising means. Several objects may also be connected to one agent unit. An object may also include several objects that are interlinked such as to enable the agent unit to receive operational information from all interlinked objects, by virtue of being connected to solely one of these objects. In this case, the objects may be interlinked in a ring or in some other configuration. In this embodiment, the agent units 10-24 are included in a magazine (not shown) having a backplane bus which forms the network 26. The magazine has a specific size and several magazines can be readily coupled together so that more agent units can be included than the number afforded by the particular size of the magazine. In this embodiment, the backplane bus is in the form of a ring, although a straight bus structure is conceivable. Fig. 2 illustrates the structure of the messages sent in the inventive system. The Figure shows four messages 50, 52, 54 and 56. Each message is comprised of a data field DATA and an address field ADR. The data field DATA contains the information intended for a given agent unit or for the superior supervising means, and the address field ADR contains the address of this agent unit or the address of the superior supervising means. The address in the address field ADR of the first message 50 is adrl, which is the address of the first agent unit 10, the address in the address field ADR in the second message 52 is adr2, which is the address of the second agent unit 12, the address in the address field ADR of the third message 54 is adr3 , which is the address of the third agent unit 14, and the address in the address field of the fourth message 56 is adr9, which is the address of the superior supervising means 28. Thus, the first message 50 is intended for the first agent unit 10, the second message 52 is intended for the second agent unit 12, and the third message 54 is intended for the third agent unit 14, whereas the fourth message 56 is intended for the superior supervising means 28. The messages can be transmitted to the superior supervising means with the aid of some suitable transport protocol, for instance TCP/IP. Fig. 3 is a flowchart that illustrates the manner in which the first agent unit functions to send messages to superior supervising means. A stream of messages pass the network ports on respective agent units. All agent units in the network sense the messages that pass their network ports and collect and process those messages that are intended for them. The first agent unit 10, however, has an additional function and Fig. 3 describes precisely how this first agent unit transmits and receives messages. The first agent unit 10 first senses the message located at its network port, block 58. If the address ADR included in this message is different to adrl or adr9, i.e. differs from the address of the first agent unit itself or from the address of the superior supervising means 28, block 60, the first agent unit 10 allows the message to pass, block 62, and then senses the next message, block 58. If, on the other hand, the address ADR is equivalent to adrl or adr9, block 60, the message is taken into the first agent unit 10, block 64. If the address ADR is different to adrl, block 66, the message is then sent to the superior supervising means 28 on the group access port 46, block 68, whereafter renewed sensing of the network takes place, block 58. On the other hand, if the address ADR is equivalent to adrl, block 66, then the message is intended for the first agent unit 10 and said agent processes the message in an appropriate manner, block 70. This processing of the message may result in controlling of an object connected to said unit. Sensing of the network is then renewed, block 58. Naturally, the first agent unit 10 may also send its own messages to the superior supervising means . Fig. 4 is a flowchart which illustrates the manner in which the first agent unit 10 processes messages that are received on the group access port 46. There is first received a message on the access port, block 72. When the address ADR in this message is equivalent to adrl, block 74, then the message is intended for the first agent unit 10 and the unit processes the message itself, block 76. If the message has some other address, block 74, the first agent unit will transmit this message on the network 26, block 78, so as to enable the agent unit to which the message is addressed to collect the message. The first agent unit 10 may also transmit its own messages to the other agent units. In one embodiment of the invention, the first agent unit 10 is a superagent unit, in other words a supervising means on an intermediate level. The superagent unit is adapted to receive messages from the remaining agent units, which either send messages on their own initiative or upon request. The first agent unit then controls and supervises all other agent units in the network and is then able to process the information it receives from other agent units, to control these agent units in accordance with this information and to send messages to the superior supervising means, either on its own initiative or upon request. The messages sent by the superagent unit to the superior supervising means may either be own messages or messages from other agent units. The superagent unit thus relieves the load on the superior supervising means still further, resulting in a more effective supervising system. When a superagent unit is used, the network that interconnects the agent units may also have a structure that is different to the aforedescribed structures. In this respect, the network may also have an hierarchical structure. The superagent unit may optionally also lack its own objects for supervision. In a further embodiment of the invention, one or more agent units in the group may have double functions, by which is meant that the agent unit or agent units may be adapted to send messages that include operational information concerning an object that is connected thereto and that also include the supervision specific protocol, and also to send messages containing operational information that derives from the same object while using the protocol specific to this object, i.e. in the absence of protocol conversion. This is highly beneficial when a supervising system is to include "old" supervising equipment that requires the use of an object specific protocol. Naturally, this embodiment can be combined with the earlier described embodiments. A twin-function agent unit functions to supervise an object and to receive therefrom information that is transmitted in accordance with a first object specific protocol. The agent unit processes this information in accordance with the first function in the earlier described manner, and converts said information into at least one message that includes a supervision specific second protocol intended for a first supervising means. The twin-function unit is also adapted to forward transparently the received information while retaining the first protocol, i.e. without converting the information. Such a twin-function agent unit may be adapted to choose whether or not to carry out the first function, the second function or both functions simultaneously. The first agent unit 10 receives the messages in accordance with the first function and the operational information in accordance with the second function when it has not generated them itself, and is adapted to recognise the transparent forwarded information according to the second function as one or more special messages, each of which shall be forwarded to an appropriate superior supervising means. When the public switched telephone network is used as link 48, the operational information is then sent, optionally with the aid of a modem, to the second superior supervising means . Transmission will sometimes require the use of a special transport protocol, for instance TCP/IP.

Claims: CLAIMS 1. A device for supervising objects (30, 32, 34, 36, 38, 40, 42, 44) and/or information flows, wherein the device includes at least two agent units (10, 12, 14, 16, 18, 20, 22, 24) that are interconnected in a network (26) and intended to communicate with at least one superior supervising means (28) , and wherein at least one agent unit includes at least one supervising port for connection to an object, characterized by a group access port (46) that is common to all agent units (10, 12, 14, 16, 18, 20, 22, 24) in the device, said group access port being intended for connection to at least one superior supervising means (28) . 2. A device according to Claim 1, characterized in that at least one agent unit (10, 12, 14, 16, 18, 20, 22, 24) is adapted to read operational information relating to one or more objects (30, 32, 34, 36, 38, 40, 42, 44) connected thereto and to supervise and control said one or more objects, or the information flows in said one or more objects . 3. A device according to Claim 1 or 2, characterized in that a first (10) of said agent units includes the group access port (46) and is adapted to send to at least one superior supervising means (28) , via the group access port, messages that are received from all agent units (10, 12, 14, 16, 18, 20, 22, 24) in the group and addressed to said superior supervising means. 4. A device according to Claim 3, characterized in that the first agent unit (10) that includes the group access port (46) is an intermediate level supervising means that is adapted to read messages from remaining agent units (12, 14, 16, 18, 20, 22, 24) in the group and to control and supervise said remaining units. 5. A device according to any one of the preceding Claims, characterized in that the agent units (10, 12, 14, 16, 18, 20, 22, 24) are also adapted for communication with one another. 6. A device according to any one of the preceding Claims, characterized in that the agent units (10, 12, 14, 16, 18, 20, 22, 24) are adapted to receive from objects (30, 32, 34, 36, 38, 40, 42, 44) connected thereto operational information that includes an object specific protocol and to convert this information into one or more messages that includes or that include a supervision specific protocol, for transmission to a superior supervising means (28) ; and in that at least one agent unit is also adapted to send operational information received from an object to at least one superior supervising means (28) while using the object protocol specific to this object . 7. A device according to any one of the preceding Claims, characterized in that the network (26) has a ring structure. 8. A device according to any one of the preceding Claims, characterized in that the network (26) has a bus structure. 9. A device according to any one of the preceding Claims, characterized in that a modem is connected to the group access port (46) . 10. A magazine for a device according to any one of the preceding Claims, characterized by a backplane bus that includes the network (26) . 11. An object supervising system that includes a superior supervising means (28) and at least two agent units (10, 12, 14, 16, 18, 20, 22, 24) , wherein the agent units are interconnected in a network (26) and at least one agent unit includes at least one supervising port to which an object (30, 32, 34, 36, 38, 40, 42, 44) is connected, and wherein each agent unit is adapted for communication with the superior supervising means, characterized by one single group access port (46) that is common to all agent units (10, 12, 14, 16, 18, 20, 22, 24) and that connects the agent units to said superior supervising means (28) . 12. A method of transferring messages between a group of agent units (10, 12, 14, 16, 18, 20, 22, 24) , that are at least two in number, and at least one superior supervising means (28) , wherein the agent units in said group transfer to said superior supervising means messages (56) that concern objects (30, 32, 34, 36, 38, 40, 42, 44) connected thereto, either upon request or on their own initiative, characterized in that the agent units (10, 12, 14, 16, 18, 20, 22, 24) send the messages (56) to the superior supervising means (28) through the medium of an access port (46) that is common to all agent units in the group. 13. A method according to Claim 12, characterized in that a first of said agent units (10) in the group receives all messages (56) from other agent units (12, 14, 16, 18, 20, 22, 24) and addressed to said superior supervising means (28) , (58, 60, 64) , and sends these messages (56) to said superior supervising means (28) , (64, 68) . 14. A method according to Claim 12 or 13, characterized in that a first of the agent units (10) in said group receives all messages (50, 52, 54) from the superior supervising means (28) intended for all agent units (10, 12, 14, 16, 18, 20, 22, 24) in the group via the group access port (46) , (72) and sends all messages that are not intended for itself (52, 54) to remaining agent units (12, 14, 16, 18, 20, 22, 24) in the group (74, 78) . 15. A method according to any one of Claims 12-14, characterized in that at least one agent unit (10, 12, 14, 16, 18, 20, 22, 24) in the group also sends messages (50, 52, 54) to at least one other agent unit in said group. 16. A method according to any one of Claims 12-15, characterized in that the agent units (10, 12, 14, 16, 18, 20, 22, 24) in said group receive from objects (30, 32, 34, 36, 38, 40, 42, 44) connected thereto operational information that includes object specific protocols, converts this information into at least one message that includes a supervising specific protocol, and sends this message to at least one superior supervising means (28) . 17. A method according to Claim 16, characterized in that at least one agent unit also sends operational information received from an object to at least one superior supervising means while using associated object specific protocol. 18. A method for transmitting messages between a group of agent units (10, 12, 14, 16, 18, 20, 22, 24) , that are at least two in number, and at least one superior supervising means (28) , wherein the agent units in said group send messages concerning objects (30, 32, 34, 36, 38, 40, 42, 44) connected thereto upon request or on their own initiative, characterized in that a first of said agent units (10) supervises and controls remaining agent units (12, 14, 16, 18, 20, 22, 24) in said group and transfers to at least one superior supervising means (28) messages that concern supervised agent units, either upon request or on its own initiative, through the medium of an access port (46) that is common to all agent units in said group. 19. A device for supervising objects and/or flows of information, comprising at least two agent units that are connected to one another in a network and adapted for communication with at least one superior supervising means, wherein at least one agent unit includes at least one supervising port for connection to an object; and a group access port that is common to all agent units in the device, said group access port being intended for connection to at least one superior supervising means. 20. An object supervising system comprising at least two agent units, wherein said agent units are mutually connected in a network and wherein at least one agent unit includes at least one supervising port to which an object is connected; a superior supervising means with which each agent unit is able to communicate; and one single group access port that is common to all agent units and that connects the agent units with said superior supervising means. 21. A method of transmitting messages between a group of agent units, said units being at least two in number, and at least one superior supervising means, wherein the agent units in said group transfer to the superior supervising means messages that concern objects to which they are connected, either upon request or on their own initiative, through the medium of an access port that is common to all agent units in said group. 22. A method of transmitting messages between a group of agent units that are at least two in number, and at least one superior supervising means, wherein the agent units in said group send messages concerning objects that are connected thereto either upon request or on their own initiative; and wherein a first of said agent unit supervises and controls remaining agent units in the group and sends to at least one superior supervising means messages that concern supervised agent units, either upon request or on its own initiative, through the medium of an access port which is common to all agent units in the group.

Inventors: BLOMKVIST PETER, JOHANNSEN BERNDT, BLOMKVIST, PETER, JOHANNSEN, BERNDT
Applicants: BLOMKVIST PETER, ERICSSON TELEFON AB L M, JOHANNSEN BERNDT, BLOMKVIST, PETER, JOHANNSEN, BERNDT, TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
Application year: 1996
Main classification: H04L12
IPC codes: H04L12