EF System: Automatically Re-queue and Reprocess CAD Events

Comments: 2 - Last Comment by dcox2 on Mar 6, 2017  
Posted on Feb 28, 2017
TitleAutomatically Re-queue and Reprocess CAD Events
Name/Agency Point of ContactDan Cox - South Sound 911
Version of EdgeFrontier06.03.0000.04298

Hello EdgeFrontier Users!

South Sound 911 has developed several different EdgeFrontier systems which trigger in-house business processes upon detecting specific events in our CAD system. For example, we have processes that trigger when specific units are dispatched or primary units are assigned to an event. We found that server and network outages would occasionally disrupt these processes and decided that a system to re-trigger these events would be valuable to our users. This is also useful during and following patches or configuration changes to the CAD system because it allows monitoring of expected vs. actual notifications.

The “ReQueue_Missed_Events_Or_Updates” EdgeFrontier system provides us with the ability to detect when data is missing, add any events with missing data to a queue, and then request event information for each event in the queue. The queue is implemented as a database table and therefore can be used from within EdgeFrontier and by applications which write events numbers directly to the queue.

Basic Design:

  • Consists of:
    • An EdgeFrontier system which reads from a SQL Table  (queue) and then runs IFCAD commands to request event information from the CAD system
    • A database table which holds an event number, information on the requester of the event and the time the event was requested to be re-queued
    • Several SQL stored procedures which read, delete and insert rows into the queue
    • A web based application which can be used by support staff to add event numbers to the queue
    • A SQL job which runs a comparison to detect differences between a local data warehouse and the Hexagon CAD database.

The attached zip file includes the following:

ReQueue_Missed_Events_sqlObjects.SQL – This SQL script will create the database objects needed by the re-queue system. Note: We recommend using a different database for these objects, we do not have them in our CAD database.

SS911_ReQueue_Missed_Events_Or_Updates.XML  - Primary EdgeFrontier Re-queue system

SS911_Send_CAD_Event_ReQueue_Command.XML (Optional) – Secondary EdgeFrontier system which demonstrates the re-queue functionality in the primary system.

CADEventRequeue Visual Studio Solution (Optional) – Support Staff application which can be used to manually insert events into the queue based upon event number or agency ID and date / time.


Using this re-queue system will require some configuration and setup. Possible steps include:

[] Modifying the ReQueue_Missed_Events_sqlObjects.SQL script with any modifications needed for your environment. Note: We recommend using a different database for these objects, we do not have them in our CAD database.

[] Modifying SS911_ReQueue_Missed_Events_Or_Updates.xml– The EdgeFrontier system will need modifications done to many of the objects to connect to your database. Additionally, the following global variables will need to be created in EdgeFrontier

  • @SS911_ReQueue_Missed_Events_Or_Updates_Database@ - The database that contains the event queue
  • @SS911_ReQueue_Missed_Events_Or_Updates_Limit@ - The number of events that should be read each time events are “Re-queued”. This value should be used to prevent re-queue requests from overwhelming the CAD system

[] Modifying the CADEventRequeue visual studio solution by adding database read, write and connection methods. (Optional)

The SQL Job which runs an automated comparison of a local warehouse and the Hexagon database has not been included as it is very specific to our business logic. This portion of the process is not required for the system to operate, but does allow us to detect and re-queue any events that might be missing on an hourly schedule. Feel free to let us know if you run into any trouble implementing this for your CAD configuration.


We hope that you find this system useful! Please post below if you have any questions or feedback.




Dan Cox


South Sound 911


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RE: Automatically Re-queue and Reprocess CAD Events
Posted on Mar 1, 2017 in response to: dcox2

Great idea, thanks for sharing Dan!

The Web Application you included is a big time saver and can be used with just the EF System alone, is that correct?  In other words, just getting the system setup without worrying about additional SQL connections to non-CAD databases is enough to get the web application to work too.

Also, this is working with IFCAD930 right now, correct?

RE: Automatically Re-queue and Reprocess CAD Events
Posted on Mar 6, 2017 in response to: Rob Oesch

Hi Rob!

Yes, the Web Application writes directly to the queue used by the ReQueue_Missed_Events_Or_Updates EdgeFrontier system. In our configuration, the queue (SQL table) was located on a different database server than the Hexagon Live_930 database. If this re-queue system will be used by another agency in a similar way, a connection to their database will need to be setup in EdgeFrontier to allow access to the queue. 

Yes, this system is running in production with IFCAD930. 

Hope this helps!


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