Communications: electrical – Continuously variable indicating – With meter reading
Patent
1996-08-07
1999-10-26
Cuchlinski, Jr., William A.
Communications: electrical
Continuously variable indicating
With meter reading
34082506, 34082554, 34082507, G06F 1500
Patent
active
059736100
DESCRIPTION:
BRIEF SUMMARY
The invention relates to a system for automated selection of a communications unit for refrigerating containers which acts as an intermediate station between a refrigerating container unit which is to be monitored and a central monitoring station where all refrigerating containers as power consumers and transmitters/receivers are connected to the power supply grid using coded messages.
The international standard ISO10368 (Freight thermal containers--Remote condition monitoring) regulates the manner in which a single central monitoring station exchanges information by means of power cables with a number of communication units, modems, which are fitted into refrigerating containers placed onboard ships. The purpose of this is to perform central monitoring of the climatic conditions in the individual refrigerating containers and when needed to perform changes in the otherwise local control of refrigerating power, blowers, etc. Using the terminology of the international standard mentioned above and according to a recommended design, an MMU (Master Monitoring Unit) is used as a central monitoring station which via an HCCU or LCCU (High and Low Data Rate Central Control Unit, respectively) communicates with several RCDs (Remote Communications Devices) which are each closely related to a refrigerating container. A refrigerating container with a communications unit has a permanent identification code.
However, it has turned out in practice that in larger areas it is not sufficient to rely on the communication which may be transmitted on varying cable lengths from the individual container to the central monitoring station, and hence intermediate stations are used which each have the possibility to monitor a number of refrigerating containers and to communicate with the central monitoring station or a network of central monitoring stations. These provide an opportunity for an improvement in the reliability of communication which has not been realized until now. When deposing and connecting a refrigerating container to the power grid, in practice one would not wish to perform a manual identification of it towards the system nor would one wish to be tied to a communications protocol for deposing, such as filling up an area in a seaboard terminal in any particular order. This would also be in conflict with the desire to distribute the refrigerating containers while taking the stability of a ship into account, a distribution which is performed by a central inventory control system dependent on the knowledge of the contents of the individual refrigerating containers.
It has hence been realized that it is possible to expand the automatic logging-on to the network which is already known, by letting the system find the route of communication which provides the largest reliability of communication as well as finding alternative routes of communication in case of serious interference, possibly break-down of a communications route already established. In other words, the system is built in such a way that an individual refrigerating container is at any time communicating with an optional central monitoring station which is connected by a network, as long as the quality of communication is sufficient.
This is obtained in a structure of the communications system which is particular in that the central monitoring station transmits a query code at regular intervals which causes a response from the refrigerating container units, that newly arrived containers are given a network address and a responsible intermediate station which takes over the direct communication between the refrigerating container unit and the central monitoring station, that errors which are determined in the structure of data or data content causes a predetermined number of attempts from the first responsible intermediate station of reestablishing the communications link, and that other intermediate stations subsequently try to take over the communication with the refrigerating container. Such a structure enables safe and efficient monitoring of refrigerating
REFERENCES:
patent: 3961323 (1976-06-01), Hartkorn
patent: 4234926 (1980-11-01), Wallace et al.
patent: 4885564 (1989-12-01), Vercellotti et al.
patent: 4896277 (1990-01-01), Vercellotti et al.
patent: 5568121 (1996-10-01), Lamensdorf
Hansen Per Juul
Jensen Peter Nyegaard
Knakkergaard Kaare
Sahl Bj.0.rn
Beaulieu Yonel
Cuchlinski Jr. William A.
Lanng & Stelman A/S
Safran David S.
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