Enhanced and Standard Alarm Delivery Explained
Information on the difference between Enhanced Alarm Delivery and Standard Alarm Delivery feature.
Standard Alarm Delivery:
Prior to Continuum 1.7, alarms were delivered from the controller to each workstation on the network, if it is online as viewed from the controller, whether or not it is a recipient of the alarm. The first workstation which receives the alarm logs it to the SQL database. The alarm is broadcast and if for some reason it doesn't get logged there is no guarantee it will be delivered. It gets broadcast once.
Enhanced Alarm Delivery:
The engine for alarms was changed so that alarms could be delivered to Workstations that were temporarily offline. To accomplish this Continuum implemented Microsoft Message Queuing (MSMQ). The controllers generate alarms based upon criteria set up in alarm enrollments. These are logged in the database by the first workstation that receives the alarm which then hands it off to MSMQ for delivery to all workstations in the recipient list. The controller still sends the alarms to all online workstations. If a workstation is offline, alarms are stored in an outgoing queue that will be delivered once the Cyberstation is back online. Acc.App.AlarmServer.exe or the Alarm Delivery Server is the process that handles alarms and hands them off to MSMQ which is handled by the Windows Message Queuing service.
To view the queues, go to Administrative Tools> Computer Management> Services and Applications> Message Queuing
Enabling Enhanced Alarm Delivery when upgrading or with a new install
This is accomplished by leaving the default checkbox for Enhanced Alarm Delivery selected in the database initialization step on a new install or when upgrading to a version greater than 1.7x. MSMQ will then be installed as part of the Cyberstation installation or upgrade.
Note: If the Enhanced Alarm Logging checkbox is not checked initially, the Enhanced Alarm Delivery checkbox may become unselectable. See Installing Continuum Database for the First Time on a Multi-User LAN System in the Installation Guide
Enabling enhanced alarm delivery in a system that doesn’t have the checkbox selectable
Manually Install MSMQ
- Start> Run> type cmd then click OK (to open a command prompt)
- At the DOS prompt type cd\ then enter (places the cursor at the root)
- cd \program files\continuum\install then enter
- Type cscript MSMQInstall.js then enter (Windows component wizard Installs MSMQ)
- When the script is finished, one of the lines will indicate that MSMQ started successfully
- Type exit
Updating the database
Note: Ensure you have a recent database backup
- Run Database Initialization,
- Select Server if LAN or Stand Alone accordingly
- Select Enhanced Alarm Delivery checkbox
- Select update existing database and the click continue
- If this is a LAN installation, Manually install MSMQ on each Cyberstation according to the instructions above (step 1). MSMQ will now be used for guaranteed alarm delivery.
Caution: Make sure that all workstations are updated at the same time. Operating Continuum while using workstations with both types of alarm delivery (PSS may refer to this as MIXED MODE) options will bring undesired results.
- Uninstalling MSMQ on a workstation (if needed at some point)
- Go to Control Panel> Add/Remove Windows Components> Deselect Message Queuing
- Say Yes to the warning message
Also check the following:
Add a column to the alarm list view check the loggingWSId and see if the alarms are being delivered to another workstation that is no longer used. If it is no longer needed delete that WS out which could correct this issue..