Monitoring a Controller's online or offline Status

[Product_Support]

Issue

Needing to monitor a controller's online or offline status. I/NET AMT will generate a station lost alarm when a controller is offline, however it is sometimes desired to have a point that can be monitored to alarm as well.

Product Line

TAC INET

Environment

• subLAN
• Controller Lan; C-LAN
• Xenta 527

Cause

I/NET AMT will generate a Station lost alarm when a controller is offline, however it is sometime desired to have a point that can be monitored to alarm as well.

Resolution

Monitoring SubLAN Controllers

1. Connect to the Sub Lan Interface Controller (7798, 7793)
2. Create an internal DA point called LLSSPP_Offline, with LLSSPP being the address of the subLAN device
3. Add a Calculation to the point LLSSPP_Offline
4. Enter this Calculation: OLD(P0)
5. Set P0 to equal any External input point the subLAN device LLSSPP
6. Click okay
7. The result of this calculation is that the point will equal 1 whenever the referenced point goes old

Monitoring Controller LAN or C-LAN devices

1. Connect the Controller you wish to monitor
2. Change an external point's Global Level to "Link" (If a point already is set to system, use it.)
3. Connect to a second Controller on the same physical C-LAN (for best results use one physically closer to the NPR or Tap)
4. Create an indirect point referencing the point created in step 2
5. Create an internal DA point called LLSS_Offline, with LLSS being the address of the controller
6. Add a Calculation to the LLSS_Offline point
7. Enter this Calculation: OLD(P0)
8. Set P0 to equal the indirect point created in step 4
9. Click OK
10. The result of this calculation is that the point will equal 1 whenever the indirect point goes old, which should only occur when the controller is offline. 

Monitoring NPR or Xenta 527 devices

1. Connect to a Controller under the device you wish to monitor
2. Change an external point's Global Level to "system" (Use an existing global point if available)
3. Connect to a second Controller under the device you wish to monitor
4. Change an external point's Global Level to "system" (Use an existing global point if available)
5. Connect to a controller underneath a different NPR or 527 
6. Create an internal DA point called Link _LL_Offline, with LL being the Link address of the 527 or NPR being monitored
7. Create 2 indirect points referencing the global points created in steps 2 and 4
8. Add a Calculation to the Link _LL_Offline point
9. Enter this Calculation: OLD(P0)&OLD(P1)
10. Set P0 and P1 to equal the indirect points created in step 7
11. Click okay
12. The result of this calculation is that the DA point will equal 1 whenever both of the referenced indirect points go old.  This should only happen when communication is interrupted to both controllers indicating the most likely cause is the NPR being offline. Please be aware of other potential causes of 2 controllers on the same link going offline. Examples include power circuit failure or cut wire when selecting which controllers to monitor.