DMX FAQ


FAQs for DMX.  Post questions if you don't see it here!

 

1. Can I use this (not mentioned on the USB-DMX Interface page) USB-DMX interface?

     If it is based on FTDI's FT232RQ USB-serial converter chip, then probably!  If not, then maybe, maybe not.  Artemis Bridge Tools attempts to add support for some other interfaces, but such support may or may not have been tested yet so see the associated web site for more information.

 

2. What does the DMX control?

     Whatever you've got hooked up to it!  It's typically lights, but DMX-enabled special effect gear (smoke machines, etc.) are also available.  If you're into hardware hacking, you can make it trigger just about anything.

 

3. Is it expensive?

     Depends.  If you are comfortable working with electronics (soldering, etc.), then it doesn't have to be.  A starter kit could be ~$50 USD.  On the other hand, DMX is designed for use in the professional entertainment lighting industry.  There's all kinds of stuff you can buy.

 

4. What is DMX?

     DMX-512 is the Digital MultipleX signal protocol that uses a serial communication framework (RS-485) and a particular data packet system to control up to 512 separate addresses on the serial bus with 8-bit commands.  tl;dr: Serial Communication Bus.

 

5. Is it worth getting into this mess for some bridge lights?

     Yes.

 

6. Does Artemis support DMX on multiple bridges?

     As of 2.0, you can now run your DMX rig on either the server (for ship 1 = Artemis) or on a computer running the Main Screen (for any ship other than Artemis) linked into the server.  The server dictates when the cues are triggered, but the client Main Screen will run its own DMX file.

 

7. Why doesn't my light work?

     Good question.  Could be several reasons:

     a) You're addressing it incorrectly - Is your controller set to the address you expect?  Have you set your DMX file to that address?  Some digital controllers increment from their setpoint, and Artemis adds one to the address in the file as well.

     b) Is it powered?  Make sure your power supply has the juice for all the lights it's supporting!

     c) Are your controller and lights set up the same way?  There are 2 types of LED arrays - Common Anode and Common Cathode.  Common Anode has the +12V side tied together and separated grounds.  Common Cathode has the grounds tied together and separated +12V sides.

     d) Are you running multiple instances of Artemis on the same machine?  Only the first one launched can control lights, since the app claims exclusive access to the DMX controller as soon as the app launches.  So if you run the server and a client on the same machine, make sure the server is the first one launched.