Smart.Permissive displays the conditions a device needs before it can start, with whether each condition is met, so the operator can see which condition is preventing the start.

ISA-101 recommends a permissive list next to every device that can be started, so that a start button that does nothing is not left unexplained. Colour is used only for the conditions that block: a met condition is shown in a neutral colour, so the one condition that is not met stands out in a list of twelve.

Start permissives for a feed pump

Toggle the conditions to see the verdict change. The advisory condition is listed but never blocks the start. Enable bypass and press a condition: the component raises the bypassRequest event and does not change anything itself. In this demo the page acts as the application and applies the bypass with the user name.

Field simulation

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Interlocks on a running compressor and first-out

An interlock trips a running device. When it does, the condition that went unhealthy first is the one that matters; the others followed as a consequence. The first-out condition is determined from the timestamps supplied by the application. Press Trip: the high discharge temperature is stamped 400 ms before the vibration and the motor overload that followed it, and it is the one marked as first-out.