Analog to DMX outboard

Information on this page may be out of date or apply to old equipment. Use with caution.

The analog to DMX outboard is going to be a little box for when you don't have a full lighting desk available. It gets power from the Analog to DMX box, and sends back different voltages, to control the Analog to DMX box, which then controls the DMX devices at the other end.

How

• ONE connection of DA15
  • channels on pins 1 to 12
  • 10v in from Analog to DMX on pin 13
  • Gnd in on pin 14
  • Gnd out on pin 15

Why are there two grounds?

• The Analog to DMX box expects a reference Gnd from wherever it gets it's signal, this can be used, in conjunction with the AREF of some microcontrollers, to boost or cut the difference between 'reference' and signal (channels), so that was given a separate line. Usually, just leaving this alone or common (i.e. pins 14 and 15 bridged) is fine - it's main reason for existance is to be used as part of a compensator for long cable runs making voltage drops.
• The Analog to DMX also sends 0v ground out to it's controlling devices, so they can operate - rather than being boxes of variable resistors.
• Compensation happens at the slave end. Doing it at the control end risks someone coming along sometime in the future, and splitting the channels off the lines - in a worst-case scenario, they then compensate for long lines, something gets more than 10v without expecting it...