The Time Filter has native support for the ALEXA by use of the ALEXA Sync and Power cable available from Tessive (part # TCAB-RS).  Through this single cable, the Time Filter receives both power and synchronization signals from any of the ALEXA's RS ports.  This method of synchronization supports any frame rate of the ALEXA from 1 fps to 60 fps.  

To configure the Time Filter Controller for use with the Arri Alexa, change the SYNC MODE in the SETTINGS submenu to ARRI ALEXA.

NOTE:  THE ALEXA ONLY PROVIDES SYNCHRONIZATION SIGNALS WHEN IT IS RECORDING, SO THE TIME FILTER IS ONLY ACTIVE DURING RECORDING.  When not recording, the Time Filter will switch to a static (not shuttering) neutral density value that is equivalent to the total light loss when shuttering is active to keep exposure the same.

The ALEXA is capable of a 358-degree shutter.  When the Time Filter Controller requests a 360-degree shutter, using the 358-degree shutter of the ALEXA is sufficiently close.