How Continuum determines if an Infinity Controller node is offline.

[Product_Support]

Issue

What has to happen for CyberStation to generate an offline controller alarm.

Product Line

Andover Continuum

Environment

• CyberStation
• Infinity Controller
• Offline alarms

Cause

Receiving offline controller alarms yet controller appears to be online.

Resolution

Controllers can be offline for many reasons, such as a broadcast storm or will not come online, but consider the following points:

1. In order to determine whether a controller is offline, a CyberStation will send out a probe to the controller.  
2. The frequency with which CyberStation sends out the probe is determined by the value of the Probe Time field on the General Page of the workstation configuration.
3. If an Infinity Controller does not respond to a probe, CyberStation will wait until a probe can be sent to all other Infinity Controller nodes in the system. 
4. If the controller fails to respond to a second probe the controller is designated as Offline by CyberStation.
5. Each CyberStation evaluates the commstatus of all controllers and reports alarms to the database.  Occasionally a CyberStation will show a controller as being offline while another CyberStation will show the same controller in an online state.
6. When more that one workstation detects that the same controller is offline, this information is negotiated so that there will normally not be multiple offline alarms for the same controller.  Some versions of Continuum handle this better than others. 
7. When an offline controller responds to a probe it is marked as Return to Normal. The controller may also be marked as Return to Normal if the workstation receives some other communication from the controller.