We have a use case where we have 2 values in the same table parameter that require different hysteresis thresholds. I know we can set hysteresis on a particular severity, but it doesn't appear that we can set one hysteresis amount for Major alarms and a different one for Critical. I thought about setting up a correlated alert to add an additional delay for alert B. That would work if it was just an issue of sending both alerts to our 3rd party ticketing system, but we have Christie display on our video wall that shows any services in alarm grouped by which Satellite Lband they are sourced from, so a delay via correlated alert wouldn't avoid sending alert B to our video wall after the initial 30 seconds. The only thing I can possibly think of would be to append the parameter data to the table's Display Key so that I can use the Filter in the alarm template to filter out the different alert types but that would require a code change to the connector.
- Alert "A" = 30 seconds
- Alert "B" = 2 minutes
Let me know what you think. Any help would be greatly appreciated.
Hi Joe,
Hysteresis can indeed only be set once per parameter/filter combination and indeed you can leave out some of the severities, so that the hysteresis is only applied on for example the lower levels and for the higher levels there is no hysteresis applied at all. This seemed to be sufficient for most of the use cases we are aware off. I would be interested to learn about your specific use case and the need to define two hysteresis values for the same parameter. Feel free to share this here or send it to me in private in case you want to keep this confidential (pieter.van.compernolle@skyline.be).
Your suggestion to work with a dynamic display key can work, but combining different advanced alarming features (filters, hysteresis, conditions, ...) together is not always working the way you would expect, so I advice you to test it out very carefully before putting this in production.
Also have a need for different hysteresis for different severities.
ie: FM Deviation we want a high alarm after 3 minutes if exceeding 85kHz and a low alarm if below 65kHz for 43,200s (12 hours).
I have added a feature suggestion here:
https://community.dataminer.services/new-feature-suggestions/ability-to-have-different-hysteresis-values-for-different-severities-in-alarm-templates/
Could there be a trap generated on the device and received in DM, instead of just basing this on the measurements and thresholds in DM?
This post is from some time ago – where it states that there is no upper limit for hysteresis, so 20 min would work:
12h may need considerations though – how big is the table? Could this generate too many concurrent count-downs?
Alternatively, since the hysteresis is defined "per-parameter" in DM, what might be viable is to have an alarm with some hysteresis, then "modulate" a persistent event through a correlation rule:
e.g.
level 1
Hysteresis in Alarm Template of 5 min for a major alarm
level 2
Correlation rule for persisting event –> if that major alarm lasts more than 10 min –> elevate the alarm severity to critical
Thanks Alberto for the comments.
there are only max 5 rows in the tables of each of these elements.
device does not support traps for the alarming we are after.
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