AMX192 (often referred to simply as AMX) is an analog lighting
communications protocol
A communication protocol is a system of rules that allows two or more entities of a communications system to transmit information via any kind of variation of a physical quantity. The protocol defines the rules, syntax, semantics and synchr ...
used to control
stage lighting
Stage lighting is the craft of lighting as it applies to the production of theater, dance, opera, and other performance arts. . It was developed by Strand Century in the late 1970s. Originally, AMX192 was only capable of controlling 192 discrete channels of lighting. Later, multiple AMX192 streams were supported by some
lighting desks. AMX192 has mostly been replaced in favour of
DMX, and is typically only found in legacy hardware.
History
The name AMX192 is derived from an
acronym
An acronym is a word or name formed from the initial components of a longer name or phrase. Acronyms are usually formed from the initial letters of words, as in ''NATO'' (''North Atlantic Treaty Organization''), but sometimes use syllables, as ...
of Analog MultipleXing and the maximum number of controllable lighting channels (192). AMX was developed to address a significant problems in controlling
dimmer
A dimmer is a device connected to a light fixture and used to lower the brightness of the lighting, light. By changing the voltage waveform applied to the lamp, it is possible to lower the luminous intensity, intensity of the light output. Alt ...
s. For many years, in order to send a control signal from a lighting control unit to the dimmer units, the only method available was to provide a dedicated wire from the control unit to each dimmer (analogue control) where the voltage present on the wire was varied by the control unit to set the output level of the dimmer. In the late 1970s, the AMX192 serial analogue
multiplexing
In telecommunications and computer networking, multiplexing (sometimes contracted to muxing) is a method by which multiple analog or digital signals are combined into one signal over a shared medium. The aim is to share a scarce resource - a ...
standard was developed in the US, permitting one cable to control several dimmers.
At about the same time,
D54 was developed in the United Kingdom, and differed from AMX192 in that it used an embedded clocking scheme. AMX192 used a separate differential clock with a driver circuit similar to
RS485
RS-485, also known as TIA-485(-A) or EIA-485, is a standard defining the electrical characteristics of drivers and receivers for use in serial communications systems. Electrical signaling is balanced, and multipoint systems are supported. The s ...
, but current limited on each leg with 100Ω
resistor
A resistor is a passive two-terminal electrical component that implements electrical resistance as a circuit element. In electronic circuits, resistors are used to reduce current flow, adjust signal levels, to divide voltages, bias active el ...
s.
See also
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Dimmer
A dimmer is a device connected to a light fixture and used to lower the brightness of the lighting, light. By changing the voltage waveform applied to the lamp, it is possible to lower the luminous intensity, intensity of the light output. Alt ...
*
Lighting control console
A lighting control console (also called a lightboard, lighting board, or lighting desk) is an electronic device used in theatrical lighting design to control multiple stage lights at once. They are used throughout the entertainment industry and a ...
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Lighting control system
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DMX512
DMX512 is a standard for digital communication networks that are commonly used to control lighting and effects. It was originally intended as a standardized method for controlling stage lighting dimmers, which, prior to DMX512, had employe ...
*
RDM
External links
Strand Lighting CorporateUniversity of Exeter - Strand Archive
Stage lighting
Network protocols
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