DMXPower

DMXPower is a box that takes as input a DMX control signal to provide power, or cut power, to the devices that it controls.

DMXPower: Top panel

In the context of Brooklyn, DMXPower's control signal is in-band on the smoke machine's DMX channel. DMXPower is configured with a Main power channel (controlling the smoke machine) and an Aux power channel (controlling power to the fan that blows the smoke). Each of these power channels can be OFF, AUTO or ON.

DMX values

DMX Value	Main	Aux
0	OFF	OFF
1	AUTO	ON
2	AUTO	OFF
4	AUTO	AUTO (DMX system ready for use)
8 or more	Smoke machine outputs progressively more smoke

When the Main output is set to AUTO, it is turned on for four hours, and that four hours is reset every time smoke is triggered. In other words, it will typically remain on when AUTO, unless the smoke machine isn't being used at all.

When the Aux output is set to AUTO, it will turn on for five minutes if:

• Previously ON, or
• Smoke triggered, which restarts the five minutes

Design considerations

• The smoke machine must just work™, without having to be separately switched or off, as this is typically often forgotten.
• The smoke machine is power hungry, so it must not be powered via UPS—it would reduce the 20 minute stage battery capacity to just 5 minutes! The primary purpose of DMXPower is to automatically control power to the smoke machine from the DMX system, while not using the same power source as the DMX system.
• In-band control makes sense since the smoke machine doesn't react to the first 8 or so values, and the unit monitors when the smoke machine is triggered, on the same channel.