Event detection for smart windows and doors

A system comprising:

• one or more interfaces for receiving measurements of a current and/or an open circuit voltage (VOC) of an optically switchable device of an optically switchable window or door;
• and
• one or more processors and memory configured to:
• detect an event based on received measurements of current and/or VOC;
• send, after detecting the event, instructions to apply one or more voltage pulses to the optically switchable device for a first time period;
• integrate VOC measurements taken over a second time period after the first time period;
• and
• determine whether the integrated VOC and an integrated noise indicate (i) a wire cut event or (ii) a breakage event in the optically switchable window or door.

A method comprising:

• detecting an event based on measurements of a current and/or an open circuit voltage (VOC) of an optically switchable device of an optically switchable window or door;
• sending, after detecting the event, instructions to apply stepwise voltage increases to the optically switchable device for an increase period during a first time period;
• sending, after applying the stepwise voltage increases, instructions to apply a constant high voltage pulse to the optically switchable device for a hold period, after the increase period, during the first time period;
• integrating VOC measurements taken over a second time period after the first time period;
• and
• determining whether the integrated VOC and an integrated noise indicate the detected event is (i) a disconnect event or (ii) a breakage event in the optically switchable window or door.