Building control system having fault tolerant clients

• US 20050120081A1
• Filed: 09/27/2004
• Published: 06/02/2005
• Est. Priority Date: 09/26/2003
• Status: Abandoned Application

• Current Assignee: Siemens Building Technologies Incorporated (Siemens AG)
• Original Assignee: Siemens Building Technologies Incorporated (Siemens AG)
• Inventors: Ikenn, Amy L.
• Application Number:
  US10/950,944
• Publication Number:
  US 20050120081A1
• Time in Patent Office: Days
• US Class Current: 709/203
• CPC Class Codes: H04L 67/01 Protocols
• CPC Class Codes: H04L 69/40 for recovering from a failure of a protocol instance or entity, e.g. service redundancy protocols, protocol state redundancy or protocol service redirection management of faults, events, alarms or notifications in data switching networks H04L41/06

Abstract

A building control system is provided with one or more clients which are converted to become fault tolerant servers by replicating system data into the clients. The fault tolerant servers may be grouped with one or more clients each such that fault tolerant servers and associated clients function as groups when communications between the database server of the building control system and the fault tolerant server and the clients are interrupted. In this way, the fault tolerant server and the clients can continue functioning when disconnected from the database server.

Claims

1. ) A fault tolerant building control system comprising:

a database server for storing information about the building control system;

one or more clients, each client provided for monitoring and controlling a building control subsystem, wherein said client is provided with a database for storing data about the building subsystem from the database server such that the client will be able to continue monitoring and controlling said building subsystem if said client becomes operatively disconnected from said database server such that said client becomes a fault tolerant server.

5. ) The system according to claim 1, further comprising one or more clients, operatively connected to said fault tolerant server, wherein said data stored in said fault tolerant server database includes information about said one or more clients such that said clients can continue monitoring said subsystem after communications with said database server are interrupted as long as communications between said client and said fault tolerant server are maintained.

6. ) The system according to claim 1, further comprising one or more clients operatively provided to monitor subsystems, wherein data about each said client is assigned to a workstation such that said client can only monitor the subsystem the fault tolerant server has data for.

7. ) The system according to claim 1, wherein each said fault tolerant server is capable of acknowledging alarm events received from a controller.

8. ) The system according to claim 1, wherein the fault tolerant server is capable of displaying alarm information.

9. ) The system according to claim 1, wherein the fault tolerant server is capable of recording information about an alarm.

10. ) The system according to claim 1, wherein subsystem data is stored at the fault tolerant server, and is transmitted to the database server once connection between the fault tolerant server and the database server are reestablished.

11. ) The system according to claim 1, wherein changes to data stored at the database server are transmitted to the fault tolerant server once communications between the database server and the fault tolerant client are reestablished.

12. ) The system according to claim 10, wherein the subsystem data includes alarm data.

13. ) The system according to claim 1, further comprising a client display for displaying a message on said display of said fault tolerant server that said database server is unavailable due to network or system failures, or a combination thereof.

14. ) The system according to claim 1, wherein the database server is capable of determining the availability of fault tolerant clients by checking lock server availability.

15. ) The system according to claim 1, wherein the fault tolerant server is capable of determining database server availability by checking lock server availability.

16. ) The system according to claim 1, wherein a plurality of fault tolerant servers are provided, each fault tolerant server grouped with one or more clients such that the fault tolerant server and the clients the fault tolerant server are grouped with can continue communicating after communications between the database server each fault tolerant server group are lost.

2. ) The system according to claim 2, wherein the information shared with each fault tolerant server includes information about the subnetwork the fault tolerant server is connected to.

4. ) The system according to claim 2, wherein the data stored in the fault tolerant server includes information about each controller connected to said subnetwork so that the fault tolerant server can continue communicating with the controllers after communications between the fault tolerant server and the database server are disconnected.

3. ) The system according to claim 3, wherein the subnetwork is a building level network.

17. ) A method of converting a server dependant client to a fault-tolerant server comprising, wherein said server dependant client is operatively connected to a database server, said database server having system information necessary for the system to operate, the method comprising:

determining which databases in said databases server need to be replicated into client such that said client can operate as a fault-tolerant server;

determining available disk space for said client;

establishing appropriate partitions in the database of the client;

replicating databases from said database server into said fault tolerant server database, said databases including information about one or more clients grouped with the fault tolerant server such that the fault tolerant server and the fault tolerant clients can communicate when the clients and the fault tolerant server are unable to communicate with the database server;

establishing weights on each database; and

starting the lockserver transferred to the fault-tolerant server

18. ) The method according to claim 17, wherein clients are reconfigured to use the fault tolerant lockserver instead of a lockserver of the database server when communications between the clients and the database server are lost.

19. ) The method according to claim 17, wherein the databases replicated into the fault tolerant server include data about the subnetwork the fault tolerant server is connected to such that the fault tolerant server can communicate with the subnetwork when the fault tolerant server is unable to communicate with the database server.

20. ) The method according to claim 19, wherein the databases replicated into the fault tolerant server include data about the field panels connected said subnetwork so that the fault tolerant client can communicate with the field panels when the fault tolerant client is unable to communicate with the database server.