Tech Talk: AMX to MPX and DMX

Posted on September 29, 2010

Written by Mike Graham, product manager for CHAUVET Professional

Mike Graham pensive in front of MVP video panels.

1. What is AMX? More commonly known as Multiplex or Analog Multiplex, AMX 192 was devised to multiplex up to 192 analog dimmer levels down a four-wire cable. There are thousands of installations that still utilize AMX protocol because the dimming systems they were plugged into were built like Mack Trucks and endured.

2. The transition to DMX. Boxes to convert DMX into AMX were developed in order to avoid problems with the control. As technology began to become less expensive and started to filter into the lighting world, a new protocol was needed to handle larger dimming racks and moving lights. DMX-512 superseded AMX 192, but it came with its own sets of headaches. No standard existed in how DMX protocol was delivered to fixtures. Each manufacturer had its own method. This left smaller companies that made basic dimming and control in the lurch.

3. What is MPX and why use it? Several manufacturers began to use a system called Multiplex – a touch of both DMX and AMX. Others used their versions as MPX. So here we are with all of these smaller controllers out there with Multiplex outputs sometimes sitting right along a DMX-512 output.

When trying to answer some overwhelming questions such as, “What port do I plug into?”, or “How do I keep from ruining a fixture because multiplex puts current down the line?” follow this simple rule of thumb: if you are using like control with like dimmers, Multiplex is the way to go. If Multiplex is all your controller puts out and you want to control intelligent lights, you need to get a new controller.