D54 is an analogue 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 Lighting in the late 1970s and was originally designed to handle 384 channels. Though more advanced protocols exist such as Digital MultipleX

DMX (lighting) 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 employed ...

, it was widely used in larger venues such as London's West End theatres which had

Strand Lighting Strand Lighting is an international theatre and television lighting company founded in 1914 in London's West End that supplies lighting fixtures and controls for the entertainment industry. Strand's products have been used on countless theatr ...

dimming installations, and it was popular amongst technicians because all the levels can be "seen" on an oscilloscope. D54 is still supported on legacy equipment such as the Strand 500 series consoles alongside

DMX Earl Simmons (December 18, 1970 – April 9, 2021), known professionally as DMX, was an American rapper and actor. He began rapping in the early 1990s and released his debut album ''It's Dark and Hell Is Hot'' in 1998, to both critical acclaim ...

. Generally a protocol converter is now used to convert

down to the native D54.

History

One of the 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 is getting the control signal from a lighting control unit to the dimmer units. For many years this was achieved by providing 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 about 1976, to deal with the bulky cable requirements of analogue control, Strand's R&D group in the UK developed an 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 ...

control system designated D54 (D54 is the internal standards number, which became the accepted name). Originally developed for use on the Strand Galaxy (1980) and Strand Gemini (1984) control desks. Although a claimed expansion capability of 768 dimmers was documented, early receivers used simple hardware counters that rolled over before reaching 768, effectively preventing commercial exploitation. The refresh period would also have been slow on such a long dimmer update cycle. Instead, multiple D54 streams were supported by some later consoles. D54 was developed in the United Kingdom at approximately the same time as

AMX192 AMX192 (often referred to simply as AMX) is an analog lighting communications protocol used to control stage lighting. It was developed by Strand Century in the late 1970s. Originally, AMX192 was only capable of controlling 192 discrete channels of ...

(another analogue multiplexing protocol) was developed in the United States, and the two protocols remained almost exclusively in those countries.

Protocol

Article Authors Note: Little information is available regarding this protocol, so the below data is unverified and provided 'as is'. Electrical Parameters 1) Outputs to be short-circuit proof to 0 V to unlimited periods.
2) The termination resistor is paralleled for multiple dimmers received, e.g. 24 dimmers use 1 kΩ.
3) The termination capacitor is set to give a 1 µs time-constant, e.g. for Rt = 1k, Ct = 1,000 pF.
4) Full Level may be adjusted at the control system. Temporal Parameters {, border="1" , ----- , Parameter , , Abr. , , colspan="3" , Transmitting , colspan="3" , Receiving , ----- , , , , , Max , , Min , , Nominal , , Max , , Min , , Nominal , ----- , End of Frame pulse , , Te , , 0.5 s , , 35 µs , , - , 0.5 s , , 30 µs , , - , ----- , Inter-Frame period , , Ti , , 15 µs , , 0.5 s , , - , - , , 10 µs , , - , ----- , Sync Pulse , , Ts , , 10 µs , , 6 µs , , 8 µs , 15 µs , , 3 µs , , - , ----- , Analogue Valid Delay , , Tv , , 15 µs , , - , , - , 20 µs , , - , , - , ----- , Analogue Hold period , , Th , , Td , , 50 µs , , - , Td , , 45 µs , , - , ----- , Total Dimmer period , , Td , , 0.5 s , , 70 µs , , - , 0.5 s , , 70 µs , , - , ----- , Total Cycle period , , Tc , , 0.5 s , , - , , 40 ms , 0.5 s , , - , , 40 ms , ----- , Analogue Gate Delay , , Tg , , 20 µs , , 0 , , - , - , , - , , - , ----- , Number of Dimmers , , N , , 384 , , 1 , , - , 768 , , 1 , , - , ----- , Slew Rate , , - , , - , , 2 V/µs , , 2.5 V/µs , - , , 0 , , - Practical remarks (Found while working on a project to interface DMX512 console to Strand EC90 dimmer): 1) The frame starts with a 0 volt for (> 50us i.e. a channel time) followed by a sync pulse then (channel 1) value and so on tell the whole (384 channels) i.e. you send a 0 valued channel then the 384 channel values, this first 0 valued channel acts as a start code. 2) Every thing works fine when the sync pulse >= 10 us. 3) Unlike DMX512, you cannot shorten the frame to the no. of channels you use, the whole 384 channels + the start 0 valued channel must be sent. Again these remarks are gained from a practical project with Strand EC90 dimmer.

External links

Strand Lighting CorporateDIY D54 to DMX512 for Strand ACTION Consoles
(In German)
DMX512 to D54 Converter
Stage lighting Network protocols

History

Protocol

See also

External links