I built this control system for the dust collection system in my previous workshop in Texas.  With this system, every large piece of equipment had a radio that transmitted a coded message to the central controller whenever the equipment was turned on or off.

The controller, in turn, would actuate the appropriate solenoid valves to drive air to an air cylinder attached to the equipment’s blast gate and, once opened, turn on the Dust Collector.

When the equipment was turned off, the controller would keep the DC running for about 30 seconds longer, in case another piece of equipment was turned on (it takes a long time for the DC to spin up and down).  Then, once the DC was off, kept the Blast gate opened for a couple of minutes, just to make sure that the DC had stopped drawing air.  It worked pretty well.  I’ll be doing something similar in my new workshop…