Rules : when… then…

The brain of the tool

A rule is a sentence in two halves. When a reading does this, then that happens. That is all, and you write it with drop-down lists, not with code.

The "when"

You pick a sensor, one of its readings, and a condition: greater than, less than, equal to. You almost always add a duration: "for more than thirty minutes". That duration is the most important setting on the whole screen, and the most often forgotten.

Without it, a one-second spike, somebody opening the kiln door, raises an alarm. With thirty minutes, only a genuine drift raises one. You are not setting the sensitivity of the sensor: you are setting your own patience.

The "then"

Raise an alarm, with a severity. Send an email. Push a notification to phones. Often all three, because they are not read at the same moment.

The three rules at Les Ateliers du Vent d'Ouest

Kiln. When humidity goes above 14% for more than thirty minutes, then a medium alarm, email to Jean and Camille.

Workshop. When the temperature falls below 8 °C for more than an hour, then a low alarm and an email to Jean, the heating has failed, and the glue will not set tomorrow morning.

Extraction. When the extraction is stopped while a machine is drawing current, then a high alarm and an immediate push notification. That one is about safety, not quality.

Changing rules without fear

A rule can be switched off without being deleted: handy while work is being done on the kiln, so your own maintenance doesn't wake you up. Changing a rule alters neither the history already recorded nor the alarms already open.