Patent Publication Number: US-2005120081-A1

Title: Building control system having fault tolerant clients

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
      This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/506,692, filed Sep. 26, 2003, which is incorporated herein by reference.  
      Cross-reference is made to co-pending application, U.S. patent application Ser. No. 10/434,390 filed on May 8, 2003 titled “Integrated Communication of Building Control System and Fire Safety System Information”, which is owned by the owner of the present application and incorporated herein by reference. Cross-reference is also made to co-pending application, U.S. patent application Ser. No. 10/671,234, field on Sep. 25, 2003 entitled “Ethernet—Based Fire System Network”, which is owned by the owner of the present application and incorporated herein by reference. Cross-reference is also made to co-pending application, U.S. patent application Ser. No. 10/199,802, filed on Jul. 19, 2002 entitled User Interface for Fire Detection System” which is owned by the owner of the present application and incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION  
      The present invention relates to a building control system provided with fault-tolerant workstations that can continue to control and monitor building subsystems even when disconnected from the building control systems database server.  
     BACKGROUND OF THE INVENTION  
      The problem with existing building control systems is that workstations, otherwise known as clients, cannot function to control and monitor the building subsystems they are provided for if they are unable to communicate with the database server of the building control system. Industries such as pharmaceutical manufacturing rely upon building control systems to verify that the environmental conditions within their manufacturing facilities remain within required parameters. The biggest obstacle for clients to operate independently when communications to and from the database server is that all of the data for the entire system is stored at the database server. While hardware redundancy may work in some circumstances, hardware redundancy is not effective if clients before separated from the database server due to a network failure. Accordingly, what is needed is a building control system whereby clients maintain at least minimal control and monitoring ability when communications between the client and the database server are lost.  
     SUMMARY OF THE INVENTION  
      The present invention relates to a building control system comprising a database server and one or more clients that have been converted to fault tolerant servers by replicating system data into the one or more clients, and providing the clients with lockservers. The fault tolerant servers may be grouped with other clients so that the fault tolerant servers and the clients can function as a group when communications from the database server are lost. Each fault tolerant server is provided with a lockserver, a job database which includes information such as system security, and data for system devices to be controlled and monitored, such as lower level controllers, commonly referred to as field panels in the building control industry, and building level network information.  
      In another embodiment, the present invention may be implemented in a life safety system, so that clients can view and respond to alarms when communications are interrupted between clients and the database server.  
      In yet another embodiment, a method of converting a client into a fault tolerant client is shown. The method includes determining which databases in said databases server need to be replicated into a client such that the client can operate as a fault-tolerant server, determining available disk space for said client, establishing appropriate partitions in the database of the client, establishing appropriate partitions in the database of the client, replicating databases from said database server into said fault tolerant server database, the 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 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  shows a block diagram of an exemplary building control system in which the principles of the subject invention are utilized;  
       FIG. 2  is a block diagram of an exemplary building control system in which workstations are shown with sufficient data to operate independently of a database server;  
       FIG. 3  is a flow diagram of an exemplary manner of converting a non-fault tolerant client to a fault tolerant client; and  
       FIG. 4  is a block diagram of an exemplary life safety system in which the principles of the present invention are utilized. 
    
    
     DETAILED DESCRIPTION  
      For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and described in the following written specification. It is understood that no limitation to the scope of the invention is thereby intended. It is further understood that the present invention includes any alterations and modifications to the illustrated embodiments and includes further applications of the principles of the invention as would normally occur to one skilled in the art to which this invention pertains.  
       FIG. 1  depicts a system block diagram of an exemplary building control system (BCS)  100  in which the subject invention may be used. The building control system  100  is depicted as a distributed building system that provides control functions for any one of a plurality of building operations. Building control systems may thus include HVAC systems, security systems, life or fire safety systems, industrial control systems and/or the like. An example of a BCS is the APOGEE™ system available from Siemens Building Technologies, Inc. of Buffalo Grove, Ill. The APOGEE™ system allows the setting and/or changing of various controls of the system, generally as provided below. It should be appreciated that the building control system  100  is only an exemplary form or configuration for a building control system. Therefore, the principles of the subject invention are applicable to other configurations and/or forms of building control systems.  
      The building control system  100  includes at least one supervisory control system or workstation, though in the present embodiment workstations  102   a  and  102   b  are shown. Workstations  103   a ,  103   b ,  103   c  and  103   d  are provided as monitoring stations that allow users to monitor the condition of points in the building control system  100 . Building control system  100  further comprises a system database server  104 , a plurality of field panels represented by field panels  106   a  and  106   b , and a plurality of controllers represented by controllers  108   a - 108   i . It will be appreciated, however, that wide varieties of BCS architectures may be employed. When all communications are intact, any workstation ( 104 ,  102   a - b ,  103   a - d ) can be used to control and monitor and provide a user interface for all of the devices in BCS  100 . While  FIG. 1  shows workstations  102   a  and  102   b  being directly connected to BLN  112   a  and BLN  112   b  respectively, it is understood that the hardware connections between the workstations need not be between workstations  102   a - 102   b  to the BLN networks  112   a ,  112   b , but can be from workstations  103   a - 103   d  such that workstations  102   a - 102   b  do not need to be directly connected through hardware to the BLN networks  112   a  and  112   b.    
      Each of the controllers  108   a - 108   i  corresponds to one of plurality of localized, standard building control subsystems, such as space temperature control subsystems, lighting control subsystems, or the like. Suitable controllers for building control subsystems include, for example, the model TEC (Terminal Equipment Controller) available from Siemens Building Technologies, Inc., of Buffalo Grove, Ill. To carry out control of its associated subsystem, each controller  108   a - 108   i  connects to one or more sensors and/or actuators, shown by way of example as the sensor  109   a  and the actuator  109   b  connected to the controller  108   a.    
      Typically, a controller such as the controller  108   a  effects control of a subsystem based on sensed conditions and desired set point conditions. The controller controls the operation of one or more actuators to attempt to bring the sensed condition to the desired set point condition. By way of example, consider a temperature control subsystem that is controlled by the controller  108   a , where the actuator  109   b  is connected to an air conditioning damper and the sensor  109   a  is a room temperature sensor. If the sensed temperature as provided by the sensor  109   a  is not equal to a desired temperature set point, then the controller  108   a  may further open or close the air conditioning damper via actuator  109   b  to attempt to bring the temperature closer to the desired set point. Such systems are known. It is noted that in the BCS  100 , sensor, actuator and set point information may be shared between controllers  108   a - 108   i , the field panels  106   a - 106   d , workstations  102   a - 102   b , monitoring workstations  103   a - 103   d , and any other elements on or connected to the BCS  100 .  
      To facilitate the sharing of such information, groups of subsystems such as those connected to controllers  108   a  and  108   b  are typically organized into floor level networks (“FLNs”) and generally interface to the field panel  106   a . The FLN data network  110   a  is a low-level data network that may suitably employ any suitable proprietary or open protocol. Controllers  108   c ,  108   d  and  108   e  along with the field panel  106   b  are similarly connected via another low-level FLN data network  110   b . Controllers  108   f  and  108   g  along with the field panel  106   c  are similarly connected to FLN network  110   c  and controllers  108   h  and  108   i  are similarly connected to FLN data network  110   d . Again, it should be appreciated that wide varieties of FLN architectures may be employed.  
      The field panels  106   a  and  106   b  are also connected via a building level network (“BLN”)  112   a  to the workstation  102   a  which provides connection to the database server  104 . Field panel  106   c  and  106   d  are connected via BLN  112   b  to workstation  102   b  which provides connection to database server  104 . Typically such field panels, for example field panels  106   a  and  106   b , coordinate the communication of data and control signals between the controllers  108   a - 108   e  and the supervisory computer  102   a  and database server  104 . In addition, one or more of the field panels  106   a ,  106   b  may themselves contain control programs for controlling HVAC actuators such as those associated with air handlers or the like. To this end, as shown in  FIG. 1 , the field panel  106   a  is operably connected to one or more HVAC system devices, shown for example as a sensor  107   a  and an actuator  107   b.    
      The workstations  102   a - 102   b  provide overall control and monitoring of the building control system  100  and include a user interface. The workstations  103   a - d  also provide a user interface and can be used to control and monitor the devices connected through  102   a  and  102   b . The workstations  102   a - 102   b  further operate as a BCS data server that exchanges data with various elements of the BCS  100 . The BCS data server can also exchange data with the database server  104  when communications are available. The BCS data server of each workstation allows access to the BCS system data by various applications. Such applications may be executed on the workstations  102   a - 102   b  or other supervisory computers, not shown, connected via a management level network (“MLN”)  113 .  
      When the database server  104  is available, typically a workstation, workstation  102   a  for example, is a user access point for the system components (including the field panels  106   a  and  106   b ), is operative to accept modifications, changes, alterations and/or the like (“workstation events”) from the user. This is typically accomplished via a user interface for or of the workstation  102   a . The user interface may be the keyboard of the workstation  102   a . The workstation  102   a  is operable to, among other things, affect or change operational data of the field panels  106   a ,  106   b  as well as other components of the BCS  100 . The field panels  106   a  and  106   b  utilize the data and/or instructions from the workstation  102   a  to provide control of connected devices such as devices  107   a  and  107   b  and/or the controllers  108   a  and  108   b . Field panels  106   c  and  106   d  and workstation  102   b  operate in a similar fashion.  
      The workstation  102   a  is also operative to poll or query the field panels  106   a  and  106   b  for gathering data. The workstation  102   a  processes the data received from the field panels  106   a  and  106   b , including maintaining a log of field panel events and/or logging thereof. Information and/or data is thus gathered from the field panels  106   a  and  106   b  in connection with the polling, query or otherwise, which the workstation  102   a  stores, logs and/or processes for various uses. In addition field panels  106   a  and  106   b  may initiate sending event data to  102   a  to be stored. To this end, the field panels  106   a  and  106   b  are operative to accept modifications, changes, alterations and/or the like (“field panel events”) from the user. Again, field panels  106   c  and  106   d  and workstation  102   b  operate in a similar fashion.  
      The workstations  102   a - 102   b  preferably maintain a database associated with each field panel associated with the workstation. The database maintains operational and configuration data for the associated field panel.  
      Each workstation  102   a - 102   b  is operatively connected to a web server  114  and other supervisory computers, not shown, via the MLN  113  that may suitably be an Ethernet network. Each workstation  102   a  and  102   b  uses the MLN  113  to communicate BCS data to and from other elements on the MLN  113 , including the web server  114 . The database server  104  stores historical data, error data, system configuration data, graphical data and other BCS system information as appropriate. Typically, data stored in workstations  102   a - 102   b  is redundantly stored in database server  104 . The database server  104  and workstations  102   a - 102   b  are then synchronized when communications between them are reconnected.  
      The MLN  113  may connect to other supervisory computers, not shown, Internet gateways including, by way of example, the web server  114 , or other gateways to other external devices, not shown, as well as to additional network managers (which in turn connect to more controllers/subsystems via additional low level data networks). The MLN  113  may suitably comprise an Ethernet or similar wired network and may employ TCP/IP, BACnet, and/or other protocols that support high speed data communications.  
      The field panels  106   a - 106   d  are operative to accept modifications, changes, alterations and/or the like (“field panel events”) from the user with respect to objects defined by the BCS  100 . The objects are various parameters, control and/or set points, port modifications, terminal definitions, users, date/time data, alarms and/or alarm definitions, modes, and/or programming of the field panel itself, another field panel, and/or any controller in communication with a field panel. It should here be appreciated that for the below discussion when appropriately referring to  FIG. 1 , the functionality, features, attributes, characteristics, operation and/or the like of each fault tolerant server or fault tolerant client is the same for every field panel except where indicated, and will be described as such with reference to only field panel  106   a . Therefore, the below discussion with reference to field panel  106   a  is equally applicable to all field panels unless indicated otherwise.  
      Turning now to  FIG. 2 ,  FIG. 2  illustrates workstations  102   a  and  102   b  shown in  FIG. 1  now provided with sufficient system data to allow workstations  102   a - 102   b  and monitoring workstations  103   a - 103   d  to continue to operate with at least minimum functionality when communications with the database server  104  are lost. According to the present invention, in order to allow workstations  102   a - 102   b  and monitoring workstations  103   a - 103   d  to function independently when they are operatively disconnected from the database server  104 , copies of the necessary system data may be placed in a database in workstations  102   a - 102   b  so that workstation  102   a  effectively acts as a server for monitoring workstations  103   a - 103   b  and workstation  102   b  effectively acts as a server for monitoring workstations  103   c - 103   d . Accordingly, the solution to system degradability is to divide the system  100  into subgroups A and B, wherein subgroup A comprises workstation  102   a  and monitoring workstations  103   a - 103   b , and wherein subgroup B comprises workstation  102   b  and monitoring workstations  103   c - 103   d . In this way, workstations within each subgroup A and B can continue communicating with each other in circumstances where communications are lost with the database server.  
      One practical advantage of sub-groups is that it allows each subgroup to be UL listed. This advantage will be discussed in further detail below where the present invention is implemented in a life safety system.  
      As shown in  FIG. 2 , in order to minimize data storage taken up in each workstation  102   a - 103   b , only copies of data which is pertinent to each fault tolerant workstation  102   a - 102   b  will be stored on the respective workstation, instead of copying all the system data from the database server  104  into each workstation  102   a - 102   b . Each autonomous workstation  102   a - 102   b  will have local copies of the relevant system, BLN and field panel databases so that the workstations will be able to monitor and control the subsystems they are provided databases for. The data each workstation is provided with includes the physical configuration data for anything that is physically attached to the network that the workstation will be responsible for controlling and monitoring if communications with the database server  104  are interrupted. For example, client  102   a  is provided with client  102   a  data, BLN  112   a  data, client  103   a  data, client  103   b  data, field panel  106   a  data and field panel  106   b  data, and a copy of the job database. Further, client  102   b  is provided with client  102   b  data, BLN  112   b  data, client  102   c  data, client  103   d  data, field panel  106   c  data and field panel  106   d  data and a copy of the job database. The workstations are provided with field panel configuration data since the workstations store relevant point data. The workstations need to have BLN configuration data, such as the BLN&#39;s name and address, in order to communicate with the field panels.  
      Workstations  102   a - 102   b  are also provided with a job database. The job database contains all of the global information for the entire system. This includes unique naming information and security. This will provide enough security information to allow the system to start up, even if no application can be run. In order to be able to use graphics when a workstation  102   a - 102   b  is functioning without the database server  104 , all of the graphics files will be copied over to each workstation  102   a - 102   b  when it is configured.  
      Workstations  102   a  is further provided with configuration data about monitoring workstations  103   a - 103   b , and workstation  102   b  is further provided with configuration data about monitoring workstations  103   c - 103   d  such that workstations  103   a - 103   d  can continue provide monitoring functions to users. Workstation  102   a  and monitoring workstation  103   a - 103   b  accordingly form a group that can continue to communicate when communications from the database server  104  are lost. Workstation  102   b  and monitoring workstations  103   c - 103   d  will similarly form a group that can continue to operate once communications from database server  104  are lost. Accordingly, workstation  102   a  will not be able to enable monitoring or control over the bln 2   112   b  with field panels  106   c - 106   d , and workstation  102   b  will have similar limitations. In the present embodiment, workstations  103   a - 103   b  will only be able to monitor bln 1   112   a  and field panels  106   a - 106   b , and workstations  103   c - 103   d  will only be able to monitor bln 2   112   b  and field panels  106   c - 106   d . In alternative embodiment, further configuration data can be provided to workstations  102   a  and  102   b  such that they are capable of controlling and monitoring any device within building control system  100 .  
      Each workstation  102   a - 102   b  is further provided with a lockserver, which is an Objectivity service that allows databases to function on a particular workstation. In a preferred embodiment, lockservers are only provided to a limited number of workstations,  102   a  and  102   b  for example, due to limited MLN bandwidth.  
      When communications are lost between the fault tolerant workstations  102   a - 102   b  and the database server  104  for a predetermined amount of time, the system  100  will display on the workstation  102   a - 102   b  interface that the workstation will begin functioning in fault tolerant mode, so that the user understands that the workstation will be operating with limited functionality. For functions that are disabled, the only action the user can take is to shut them down. When connections are reestablished between the database server  104  and the workstation, the workstation will receive a message that the workstation is no longer in fault tolerant mode. Any updates made at the database server  104  will be passed onto the workstation. In this embodiment, the database server  104  will be able to track the availability of fault tolerant workstations  102   a - 102   b  by checking lockserver availability.  
      Referring now to  FIG. 3 , there is depicted a flowchart, generally designated  300 , of an exemplary manner of operation of the subject invention. This flowchart  300  is described with reference to converting a normal workstation to a fault tolerant server or workstation. It should be appreciated that the steps depicted in the flowchart  300  of  FIG. 3  is only exemplary of one manner in which the subject invention functions. Other manners, as well as additional steps, less steps, or modified steps constitute valid functioning of the subject invention in accordance with the present principles.  
      The flowchart  300  begins with step  310 . In step  310 , the user will need to determine which databases in database server  104  need to be replicated. For example, for turning workstation  102   a  into a fault tolerant workstation, workstation  102   a  requires workstation  102   a  data, BLN  112   a  data, client  103   a  data, client  103   b  data, field panel  106   a  data and field panel  106   b  data, a copy of the job database and a lockserver in order to function as a fault tolerant workstation. In step  320 , it will be necessary to determine that the workstation  102   a  has the available disk space to store the necessary data. In step  330 , the appropriate partitions, which are objectivity constructs for distributing data, are created on workstation  102   a  for the system databases. In step  340 , the necessary databases and graphics files are replicated into the workstation  102   a . In step  350 , the appropriate weights on each database are set up in the workstation  102   a . In step  360 , the lockserver for workstation  102   a  is started. The workstation  102   a  is then capable of operating as a fault tolerant workstation. In step  370 , clients  103   a - 103   b  are reconfigured to use the lockserver for workstation  102   a  instead of the lockserver of the database server  104  when communications between the clients  103   a - 103   b  and the database server  104  are lost. The same reconfiguration is done for clients  103   c - 103   d  with respect to the lockserver for workstation  102   b.    
      In another embodiment, shown in  FIG. 4 , the present invention discussed with respect to  FIGS. 1-3  is implemented as a life safety system. The problem with existing life safety systems is that in circumstances when clients cannot communicate with the database server, the ability of the system to record and report alarm events is greatly diminished. In the present invention, workstations  402   a  and  402   b  will be enabled to view and acknowledge its own alarms when the database server  404  cannot be reached. In the present invention, field panels  406   a - 406   d  are provided as fire safety panels, such as the FireFinder XLS Fire Safety Panel sold by Siemens Building Technologies, and described in co-pending patent application Ser. No. 10/199,802. A key requirement of life safety systems is the ability to display, acknowledge to the field panels and record (to a local printer) all fire alarm activity. The Database server  404  can view any alarm that came in while the clients  402   a  and/or client  402   b  are still connected, and can acknowledge those alarms. New alarms coming into the off-line client  402   a  or  402   b  will be queued up and sent once communication between the client and the database server  504  are communicating again. When database server  404  is not available, workstation  402   a  or any workstation in its group (workstations  403   a - 403   b ) can view and acknowledge alarms on bLN  412   a . In a similar fashion, when database server  404  is not available, workstation  402   b  or any workstations in its group ( 403   a - 403   b ) can view and acknowledge alarms on bin  412   b.    
      A typical fire safety system network is shown in  FIG. 4 . The network  400  in the embodiment described herein actually involves several layers of interconnected subnetworks, including a management level network MLN  413 , one or more building level networks BLN 1   412   a  and BLN 2   412   b , and one or more floor level networks associated with each building level network. For example, floor level networks  416 ,  418  and  420  are associated with the BLN 1   412   a.    
      The MLN  413 , which preferably includes an Ethernet standard network employing TCP/IP protocol, includes a plurality of workstations, represented herein as workstations  402   a  and  402   b  that provide a graphical and/or text-based user interface for the fire safety system. Each of the workstations  402   a ,  402   b  is also connected to a set of fire safety devices via a lower level BLN. The workstations  402   a ,  402   b  and  403   a - 403   d  employ the MLN to share data received from such devices.  
      In accordance with good building engineering practices, the workstations  402   a ,  402   b  are PCs that are UL (Underwriter&#39;s Laboratories) listed for fire protective signaling use. The UL listing indicates that the component has been tested to meet a particular standard. In the case of fire control and alarm systems, the industry accepted standard is published by the National Fire Prevention Association (NFPA) and takes into account various government standards applicable to fire safety. The NFPA publishes the National Fire Alarm Code (NFPA 72), the Life Safety Code (NFPA 101), Recommended Practices for Smoke-Control System (NFPA 92A) and other related standards. All of these standards are recognized as an American National Standard for the engineering, installation and maintenance of fire safety systems for buildings/facilities of all types. All fire alarm/control systems should utilize only components that are UL certified for use in fire protective signaling.  
      In further detail of the fire safety devices, the workstation  402   a  is connected to a first building level network BLN 1   412   a  that facilitates communication with and among a number of fire control panels  506   a ,  506   b  that monitor and control various fire devices and functions. These fire control panels are also UL listed for fire protective signaling use. These panels  406   a ,  406   b  are specialized hardware devices that connect to networks of fire detection and notification devices, as well as providing other fire control functions. One such fire control panel is the FireFinder panel produced and sold by Siemens Building Technologies, Inc. In general, the FireFinder fire control panel includes a central processor, battery back-up, a network interface card, connections for a number of fire device networks, connections for a firefighter&#39;s phone system, dry contacts for additional functions, and a user interface including status indicators. The network interface card for each of the fire control panels  406   a  allows communication among all of the panels  406   b  and with the fire control workstation  402   a.    
      The workstation  402   a  can be regarded as residing at a management level of the fire safety system  400 . The fire control panels  406   a ,  406   b  form part of the BLN 1   412   a . As shown in  FIG. 4 , at least one of the of the fire control panels  406   b  is further connected to a plurality of floor level or device networks  416 ,  418  and  420  that include the fire control devices themselves. Each type of device is preferably connected to a common fire control panel that monitors the associated device network for trouble, receives signals from and sends signals to the device network, and usually provides power to the devices on the network. The associated fire control panel  406   b  also includes means to test the integrity of the device network  416 ,  418 ,  420 , and connected fire control devices and to produce a trouble signal, in the event of a malfunction or anomaly, that is communicated to the management level fire control workstation  402   a.    
      The workstation  402   b  is similarly connected to a building level network BLN 2   412   b  to which is connected a number of fire control panels  406   c ,  406   d . The fire control panels  406   c ,  406   d  are typically each connected to floor level networks, not shown, but which are similar to networks  416 ,  418 ,  420 .  
      The device networks accommodate different fire control devices. For instance, network  416  includes Initiating Device Circuits (IDCs), which can include smoke detectors  422  and pull switches  424 . The device network  418  includes Notification Appliance Circuits (NACs)  426  that are similar to IDCs but include a notification device, such as horns, strobes or speakers. The fire control panel  406   b  associated with each of these networks continuously monitors the integrity of these networks  416 ,  418  by passing a low level current through the circuits of the IDCs  422 ,  424  and the NACs  426 . Any disruption in this continuous current (that is not associated with an alarm condition) is identified by the fire control panel as an error condition giving rise to a trouble signal.  
      The device network  420  can be an Addressable Loop  428 , which is a network of addressed devices so that the fire control panel can selectively receive and transmit signals from detection devices on the loop. As shown in the example of  FIG. 5 , the addressable loop  428  includes an IDC smoke detector  430  and a pull switch  432 . Unlike the device networks  416  and  418 , the addressable loop  428  of the network  420  does not use a continuous signal to monitor its integrity. Since all of the devices on the loop  428  are assigned an address, the fire control panel can routinely communicate with these devices to see if they are still available. A failure to communicate with a particular addressed device causes the control panel  406   b  to generate a trouble signal that is supplied to the management level workstation  402   a.    
      In order to eliminate the need for a database server  404  that&#39;s UL Listed for life safety systems, or to allow workstations  402   a  and  402   b  to function when communications are interrupted between the workstations and the database server, workstations  402   a - 402   b  are provided with similar information that the workstations  102   a - 102   b  are provided in  FIGS. 1 and 3 . For example, workstation  402   a  is provided with client  402   a  data, BLN  412   a  data, client  403   a  data, client  403   b  data, field panel  406   a  data and field panel  406   b  data. Further, workstation  402   b  is provided with client  402   b  data, BLN  412   b  data, client  402   c  data, client  403   d  data, field panel  406   c  data and field panel  406   d  data and a copy of the job database.  
      According to the present invention, even when no database server  404  is provided, or when communications are lost between the database server  404  and the workstations, workstations  402   a - 402   b  are able to display alarms on their respective displays, such as the display shown in copending application Ser. No. 10/434,390, which is incorporated by reference herein, the point designation of the alarm, which may include information such as the name of the point, or the address of the point within the system. The display should also include information such as alarm status (Alarm, Supervisor, Trouble, etc.) and date and time. In the present invention, the user will be able to acknowledge alarms from the workstation  402   a , send alarms to the panel  406   b , and send an acknowledge alarm message to printer  450 . As the UL Listed workstations  402   a ,  403   a ,  403   b  and workstations  402   b ,  403   c  and  403   d  are provided as groups, alarm ownership may be transferred between fire workstations in each group.  
      It will be appreciated that the above-described embodiments are merely exemplary, and that those of ordinary skill in the art may readily devise their own implementations and modifications that incorporate the principles of the present invention and fall within the spirit and scope thereof.