Up until now, control systems have been one-way (unidirectional) commands sent to a machine to control the on/off, duration, and sometimes the intensity of the output and possibly the fan speed. But factor in a two-way (bidirectional) control system and the entire game changes. Think of the possibilities. Not only can we send commands to a machine but we can also monitor everything about the machine — fluid level, temperature, voltage, current, and more. Then the operator could anticipate problems before they are manifested as a loss of interference medium on stage. Add some fog or haze sensors and now the system becomes a self-regulating environment with operator monitoring and intervention. The good news is that the technology now exists. By using RDM (E1.20: Remote Device Management Over DMX512 Networks) the two-way communication is accomplished and anything that can be configured on the machine can be done at the console, anything that can be monitored electronically can be reported back to the operator, and anything that can be accessorized can be made to be RDM-enabled.
From “Buyers Guide: Haze Machines” by Richard Cadena, PLSN, Nov. 2009
