Using oldest or newest parameters to determine outdated source alarms

Enabling the Outdated Alarm on a data source means you can be notified when the latest data time of that data source is older than a configurable time period. For example, this data source is configured with a maximum timeout of 1 day:

Looking at the Sources view, we can see that the latest data of this data source occurs on 2021-08-07, which is today's date (as of writing this article). Therefore, the data source is not considered to be outdated:

However, looking at the Parameters view reveals that only 1 of the 2 parameters is actually up-to-date; the other has a latest data time of 2021-08-04, which is 3 days ago:

At this point, I need to decide if my use case requires me to be notified if any parameter is out of date. If so, the default configuration of the outdated alarm will need to be changed, such that the Latest data field is associated with the Oldest parameter instead of the Newest parameter:

After making this change, and looking again at the Sources view, we can see that the latest data of the data source now occurs on 2021-08-04, which is the same as the oldest parameter. And since this exceeds the configured timeout of 1 day, the outdated alarm will be triggered:

In summary, an easy way to decide what configuration to choose for your own use case is to answer the following questions:

1. Do you want to be notified only if all parameters are out of date? If so, no change is required to the default configuration: Latest data will already be set to Newest Parameter
2. Or do you want to be notified if any parameter is out of date? If so, change the Latest data setting to Oldest Parameter