The new ESS rules are all polling rules. I was not sure how often to poll, but chose 10 seconds as a reasonable compromise between polling far more often than new data arrives, and having a long delay after new data arrives. What is the interval between updates for the temperatures and humidity/dew-point sensors? If it is very different than 60 seconds, then max_data_age should probably be changed from 180 seconds. I wanted the rules to have a chance to miss 1 or maybe 2 updates (e.g. due to restarting an ESS) but not much more than that. If too short then we'll get false alarms. If too long then we wait needlessly long before realizing the Watcher isn't getting the data it needs.

Pull request: https://github.com/lsst-ts/ts_config_ocs/pull/42

How often a sensor sends data depends on the type of sensor and, in case of the temperature sensor, on the amount of temperature probes attached. But new data may be expected at least once every 2 seconds. The data in the EFD should give a good indication of this.

Reviewed in GitHub.

Updated as per reviewer suggestions. Merged to develop. Release awaits ts_xml 10.1 (see DM-32270)