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65-474: All stage lighting accessories fall into one of three distinct categories: components installed inside the fixture, components affixed to the front of the fixture (in front of the lens), or components mounted elsewhere on the exterior of a fixture (to the side, top or bottom). Barn doors , or occasionally a set of barn doors , are an attachment fitted to the front of a Fresnel lantern , a type of lantern used in films, television, and theatres. The attachment has

130-411: A multi-drop bus topology with nodes strung together in what is commonly called a daisy chain . A network consists of a single DMX512 controller – which is the master of the network — and one or more slave devices . For example, a lighting console is frequently employed as the controller for a network of slave devices such as dimmers , fog machines and intelligent lights . Each slave device has

195-500: A 5-pin XLR connector on the product. In such cases all the following additional requirements shall be met: 1) The alternate connector shall not be any type of XLR connector. 2) The alternate connector shall not be any type of IEC 60603-7 8-position modular connector except as allowed in clause 7.3. 7.2 Equipment intended for fixed installation with internal connections to the data link Fixed installation products with internal connections to

260-503: A DMX512 "IN" connector and usually an "OUT" (or "THRU") connector as well. The controller, which usually has only an OUT connector, is connected via a DMX512 cable to the IN connector of the first slave. A second cable then links the OUT or THRU connector of the first slave to the IN connector of the next slave in the chain, and so on. For example, the block diagram below shows a simple network consisting of

325-400: A controller and three slaves. The specification requires a 'terminator' to be connected to the final OUT or THRU connector of the last slave on the daisy chain, which would otherwise be unconnected. A terminator is a stand-alone male connector with an integral 120  Ω resistor connected across the primary data signal pair; this resistor matches the cable's characteristic impedance . If

390-525: A fixed position can be used for multiple "specials" in dozens of locations. Two of the most prominent models are the Elipscan by Meteor and the Rosco I-Cue. A pattern holder or gobo holder, is a metal frame designed to hold a gobo . Gobo holders are placed inside a fixture through a specifically designed opening, which places the pattern directly in the focal plane of the fixture. By placing the pattern inside of

455-549: A hard connection between signal common and ground are permitted but their use is strongly discouraged. Several possible grounding configurations that are commonly used with EIA485 are specifically disallowed by E1.11. The original DMX512 1990 specified that where connectors are used, the data link shall use five-pin XLR style electrical connectors (XLR-5), with female connectors used on transmitting (OUT) ports and male connectors on receiving ports. The use of any other XLR-style connector

520-778: A nominal characteristic impedance of 120 Ω . Also, cables designed for EIA485 typically meet the DMX512 electrical specifications. Conversely, microphone and line-level audio cables lack the requisite electrical characteristics and thus are not suitable for DMX512 cabling. The significantly lower impedance and higher capacitance of these cables distort the DMX512 digital waveforms, which in turn can cause irregular operation or intermittent errors that are difficult to identify and correct. Cat5 cable , commonly used for networking and telecommunications, has been tested by ESTA for use with DMX512A. RJ45 connectors are used by some DMX-compatible hardware with ESTA standard or proprietary pinouts. At

585-443: A packet. However, it does require that packets be transmitted so that the leading edges of any two sequential BREAKs must be separated by at least 1204 μs, and receivers must be able to handle packets with break-to-break times as short as 1196 μs. The minimum break-to-break transmit time can be achieved by sending packets that contain at least 24 slots (by adding extra padding bytes, if necessary) or by stretching parameters such as

650-470: A plano-convex lens of the same angle. Theatrical Fresnel lanterns are typically made in three-, six-, or eight-inch lens diameters, with lamps ranging in power from 150 W to 2,000 W. The three-inch variety is referred to as an inkie . Fresnel lenses can be placed close to the light source and are inexpensive to produce. In film lighting lenses range in size from 2 to 24 inches, and lamp power between 150 W and 24,000 W. Fresnels use

715-407: A regular gobo holder due to the motors and gearing required to facilitate rotation. Because of their increased thickness, gobo rotators are not placed inside fixture through the specifically designed opening (the gobo slot) but instead install into the accessory (iris) slot. Installing the rotator in the accessory slot still places the pattern inside the focal plane of a fixture, allowing adjustments to

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780-627: A revision process to develop the standard as an ANSI standard. The resulting revised standard, known officially as "Entertainment Technology—USITT DMX512-A—Asynchronous Serial Digital Data Transmission Standard for Controlling Lighting Equipment and Accessories", was approved by the American National Standards Institute (ANSI) in November 2004. It was revised again in 2008, and is the current standard known as "E1.11 – 2008, USITT DMX512-A", or just "DMX512-A". A DMX512 network employs

845-607: A ring that fits inside of the color gel slot on the instrument. Because of this, barn doors have a gel slot built into them, so the light can still be colored. Depending on the size and local practices, barn doors may be attached to the pipe or the instrument with their own safety cable. In some parts of the UK, Barn doors are referred to as "Harris Flaps" Barn doors are generally not used with "profile" or " ellipsoidal reflector " spotlights because they have internal shutters which work more effectively. Barn doors are not effective at shaping

910-400: A secondary data pair is used, a termination resistor is connected across it as well. Although simple systems ( i.e. , systems having few devices and short cables) will sometimes function normally without a terminator, the standard requires its use. Some DMX slave devices have built-in terminators that can be manually activated with a mechanical switch or by software, or by automatically sensing

975-520: A single OUT connector, enabling them to control only one universe, whereas large control desks (operator consoles) may have the capacity to control multiple universes, with an OUT connector provided for each universe. Many of the more modern control desks instead of featuring multiple OUT connectors have an unshielded twisted pair connector (such as Cat 5 , Cat 5e or Cat 6 ). Such cables and systems can control up to 524,288 universes of DMX512 (32,768 subnets × 16 universes per subnet) using

1040-436: A single bus. If more than 32 unit loads need to communicate, the network can be expanded across parallel buses using DMX splitters. Network wiring consists of a shielded twisted pair , with a characteristic impedance of 120 Ω , with a termination resistor at the end of the cable furthest from the controller to absorb signal reflections. DMX512 has two twisted pair data paths, although the specification currently only defines

1105-400: A spherical reflector , with the filament of the lamp at its focus point. This effectively doubles the light delivered by the fixture, as all that is emitted backwards into the reflector is reflected back out the front. As with most lighting fixtures, the lamp and reflector cannot move independently, and are moved together as a unit to focus the beam. This is done by a slider on the bottom of

1170-638: A standardized method for controlling stage lighting dimmers, which, prior to DMX512, had employed various incompatible proprietary protocols . It quickly became the primary method for linking controllers (such as a lighting console ) to dimmers and special effects devices such as fog machines and intelligent lights . DMX512 has also expanded to uses in non-theatrical interior and architectural lighting, at scales ranging from strings of Christmas lights to electronic billboards and stadium or arena concerts. It can now be used to control almost anything, reflecting its popularity in all types of venues. DMX512 uses

1235-600: A unidirectional EIA-485 (RS-485) differential signaling at its physical layer, in conjunction with a variable-size, packet-based communication protocol . DMX512 does not include automatic error checking and correction and therefore is not an appropriate control for hazardous applications, such as pyrotechnics or movement of theatrical rigging . However, it is still used for such applications. False triggering may be caused by electromagnetic interference , static electricity discharges, improper cable termination , excessively long cables, or poor quality cables. The DMX standard

1300-466: A wide range of static theatrical and studio lighting fixtures, allowing the designer to maximize the lighting rig without crowding fixtures or over-extending the budget. Video cameras and LCD projectors can be blended into the lighting rig with minimal preparation, providing easy adjustment from the lighting console. The Right Arm conveniently repositions these devices in theatrical and church productions, corporate events, trade shows - anywhere flexibility in

1365-424: A wide variety of devices; this version recognizes this fact. Each NULL START Code packet contains no formal data or addressing structure. The device using data from the packet must know the position of that data within the packet. Dimmer packs or racks use a group of slots to determine the levels for their dimmers. Typically a dimmer has a starting address that represents the lowest-numbered dimmer in that pack, and

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1430-469: Is a thin metal or cardboard panel, similar in shape and appearance to a colour frame, but with a small diameter hole intended to reduce off-axis rays of light being projected from a fixture. This increases sharpness of the light by reducing the effect of imperfect lenses. Doughnuts are designed to fit into the colour frame holder directly outside the fixture, immediately in front of lens assembly. Because they are typically thin, doughnuts can often be placed in

1495-473: Is designed to install into the accessory slot, while the SX4 is installed directly into the fixture, between the lamp assembly and barrel. The followspot yoke is an oversized replacement yoke intended to allow an ellipsoidal reflector spot to be installed into a followspot stand and be used as a small, short throw followspot . Generally these yokes allow a much wider range of tilt than a conventional yoke, and have had

1560-401: Is further recommended that receivers have a high impedance connection between signal common and ground; such ports are referred to as isolated . The standard also allows for isolated transmitter ports and non-isolated receivers. It also recommends that systems ground the signal common at only one point, in order to avoid the formation of disruptive ground loops . Grounded receivers that have

1625-400: Is in mainly in theatrical performance venues than with touring musical concerts rigs . Gel extenders are similar to top hats in appearance, being a tube placed over the end of a lighting fixture. Unlike top hats, however, gel extenders have a colour frame holder built into the end to allow color gel to be mounted. Gel extenders are also available in a conical shape which does not constrict

1690-468: Is named after its inventor, Augustin-Jean Fresnel , who developed it for use in lighthouses . It has a 'stepped' appearance instead of the 'full' or 'smooth' face of other lenses. This allows the lens to focus the light by tilting each successive ring of glass slightly more steeply as its distance increases from the center. If the glass were completely flat, this would cause a corresponding pattern of circles of light, so Fresnel lenses are usually stippled on

1755-478: Is not compliant with the DMX standard, but may be sufficiently compatible for operation using simple adapters. Note: There is a risk of equipment damage if 3-pin XLR audio and DMX signals are plugged into each other. Note: This connector is prohibited by section 7 of ANSI E1.11 - 2008. Data 1+ and - are often swapped over. The most commonly encountered pinout is given first: Color Kinetics has their own version of

1820-489: Is prohibited. The three-pin XLR connector is commonly used for DMX512, on lighting and related control equipment, particularly at the budget/DJ end of the market. However, using three-pin XLR connectors for DMX512 is specifically prohibited by section 7.1.2 of the DMX512 standard. Use of the three-pin XLR in this context firstly presents a risk of damage to the lighting equipment should an audio cable carrying 48-volt phantom power be accidentally connected, and secondly encourages

1885-586: Is published by the Entertainment Services and Technology Association (ESTA), and can be downloaded from its website. Developed by the Engineering Commission of United States Institute for Theatre Technology (USITT), the DMX512 standard (for digital multiplex with 512 pieces of information ) was created in 1986, with subsequent revisions in 1990 leading to USITT DMX512/1990. In 1998 the ESTA began

1950-611: The Art-Net IV protocol, or 65,536 universes using the sACN protocol, and the existing Ethernet in buildings. DMX512 data is transmitted over a differential pair using EIA-485 voltage levels. DMX512 electrical specifications are identical to those of the EIA-485-A standard, except where stated otherwise in E1.11 . DMX512 is a bus network no more than 400 metres (1,300 ft) long, with not more than 32 unit loads (individual devices connected) on

2015-474: The RDM extension to DMX (0xCC), and various proprietary systems. ESTA maintains a database of alternate start codes. All slots following the start code contain control settings for slave devices. A slot's position within the packet determines the device and function to be controlled while its data value specifies the control set point. DMX512 timing parameters may vary over a wide range. The original authors specified

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2080-419: The data link layer , a DMX512 controller transmits asynchronous serial data at 250 kbit/s. The data format is fixed at one start bit, eight data bits (least significant first ), two stop bits and no parity . Each frame consists of: The start of a packet is signified by a break followed by a "mark" (a logical one), known as the "Mark After Break" (MAB). The break, which signals the end of one packet and

2145-575: The BREAK, MAB, Interslot, or Interpacket times. Most data is sent with the default Null Start Code of 00h. Quoting from the standard: 8.5.1 NULL START code A NULL START Code identifies subsequent data slots as a block of un-typed sequential 8-bit information. Packets identified by a NULL START Code are the default packets sent on DMX512 networks. Earlier versions of this standard assumed that only dimmer class data would be sent using NULL START Code packets. In practice NULL START Code packets have been used by

2210-472: The RJ-45 connector for DMX, which predates the 2008 official inclusion in the DMX512 standard. The pinout specifically for Color Kinetics LED lighting products is: The standard cables used in DMX512 networks employ XLR5 connectors , with a male connector on one end and a female connector on the other end. The cable's male connector attaches to the transmitting, female jack (OUT), and its female connector attaches to

2275-410: The absence of a connected cable. A DMX512 network is called a "DMX universe". Each OUT connector on a DMX512 controller can control a single universe. A DMX512 universe is made up of 512 channels, with each channel containing a value between 0 and 255. Each slave device in the chain can "look at" a different set of channels in order to be controlled by the master controller. Smaller controllers may have

2340-554: The addressing increases from there to the highest-numbered dimmer. As an example, for two packs of six dimmers each, the first pack would start at address 1 and the second pack at address 7. Each slot in the DMX512 packet corresponds to one dimmer. DMX does not mandate a method of 16-bit encoding for Null Start Code packets; however, many parameters of moving lights make use of encoding larger than 8-bit numbers. To control these parameters more accurately, some fixtures use two channels for parameters that require greater accuracy. The first of

2405-477: The appearance of a large set of barn doors, but in fact there are four leaves, two larger and widening on the outside, two smaller and getting narrower towards the outside. They facilitate shaping of the beam of light from the fixture, and prevent the distinctive scatter of light created by the Fresnel lens from spilling into areas where it is not wanted, such as the eyes of audience members. Barn doors are mounted with

2470-620: The beam of light output from the fixture at all. A colour frame or gel frame is a piece of folded material, made from either metal or cardboard, designed to hold colour media (gel) . Colour frames are placed directly outside the fixture, immediately in front of lens assembly. Most fixtures include an integrated holder for the frame. Some accessories designed to mount in the gel frame holder, such as Barn Doors, occasionally include an integrated replacement slot for frames. Comes in many different sizes for all types of lanterns including, profiles, fresnels, floods and par cans A doughnut, or donut,

2535-407: The colour changer allows a single fixture to output several different colours, or no colour, and to rapidly change between colours on command. Most scrollers are controlled via DMX512 protocol, but some newer models also utilize the RDM protocol. A moving mirror attachment is an ellipsoidal spotlight accessory that allows you to remotely re-position the beam of light, so that a single luminaire in

2600-451: The conductor pairing scheme used by Category 5 (Cat5) twisted pair patch cables. The avoidance of pins 4 and 5 helps to prevent equipment damage, if the cabling is accidentally plugged into a single-line public switched telephone network phone jack. In the early days of digital lighting control, several equipment manufacturers employed various connectors and pinouts for their proprietary digital control signals. The most common of these

2665-493: The data link may use the 5-pin XLR connector, but shall not use any other XLR connector. When use is made of the 5-pin XLR connector, the requirements of 7.1 and 7.1.1 shall apply. When a non-XLR connector is used, this Standard makes no other restriction or stipulation on connector choice. The contact (pin) numbering on the alternate connector should match numbering for the standard 5-Pin XLR The 8P8C modular connector pinout matches

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2730-402: The difference between using one or not and has the extended side towards the audience. This also is to help cut down on the glare and distraction of light at the lens as it exits the light fixture. Top hats are manufactured for most stationary lighting instruments with gel frames of varying sizes. While rare they may be found on automated Intelligent lighting instruments as well. Their use

2795-410: The flat side. This pattern of small bumps helps to break up the light passing through the lens and gives Fresnels their characteristic soft beam. This means that the intensity of the light is consistent across the spread of the beam of light, as opposed to being less intense around the edges as in an ellipsoidal reflector spotlight (ERS). The stepped lens design also causes less heat buildup than does

2860-413: The focal plane of a fixture adjustments to image (hard or soft edges) can easily be created. Larger pattern holders are also available designed to mount into the accessory slot on some fixtures, allowing for the use of larger gobos, or the projection of two overlapping patterns from a single fixture. Gobo rotators are metal frames designed to hold a gobo. They have a much larger cross-section (thicker) than

2925-425: The glint halation of a lighting instrument facing the audience. It also reduces flare created by the light, which is often useful when the unit is hung near the proscenium or other objects that the designer does not want to light. There are also half-hats or "eyelashes", which function in a similar manner but have only half the cylinder, and short hats, which are shorter in length. Half hats are designed to split

2990-460: The hole for a c-clamp bolt replaced with a spigot for a spot stand. City Theatrical manufactures a complete assembly which essentially turns a conventional fixture into an automated fixture . The autoyoke is a DMX512 operated assembly which provides complete remote pan and tilt control of a fixture. The autoyoke is also designed to control other accessories, including color changers and iris units. The Right Arm adds pan and tilt capabilities to

3055-415: The image (creating hard or soft edges). All gobo rotators require an external power source, separate from the lighting fixtures power. Many models allow for remote DMX512 control of motor, permitting fine control of rotation speed and orientation of pattern. Features can also include uni- or bi-directional control of the rotation of a pattern, as well as indexing (tracking a patterns position to return it to

3120-409: The lantern, or a worm track and crank in the back of the unit. The lamps work best with their bases facing up, with bulb life shortened significantly when mounted upside down. Because the reflector of a Fresnel lantern cannot be larger than its lens aperture, the lamps are not very efficient: only the light emitted straight forward or backward (and redirected forward by the reflector) is utilized, with

3185-420: The last slot of the packet and the break (MBB) can be as long as desired. A maximum-sized packet, which has 512 channels (slots following the start code), takes approximately 23 ms to send, corresponding to a maximum refresh rate of about 44 Hz. For higher refresh rates, packets having fewer than 512 channels can be sent. The standard does not specify the minimum number of slots that can be sent in

3250-477: The lens assembly. An iris is designed to reduce diameter of beam emitted from fixture. The iris assembly is different from the donut as it adjusts the diameter of the beam, not the amount of off-axis light emitted. Gam Products Inc. manufactures two different models of effect loop, the Film/FX and the SX4. Both of these devices use a ribbon punched with a pattern to project a continuous scrolling pattern. The Film/FX

3315-429: The light of a PAR lights and a narrower lens would be a better way to do this. A top hat, also known as a stove pipe or snoot, is a device used in theatrical lighting to shield the audience's eyes from the direct source of the light. It is shaped like a top hat with a hole in the top, and the brim being inserted into the gel frame holder on a lighting instrument. The cylinder allows light to pass through but takes away

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3380-403: The light plot is needed. Fresnel lantern A Fresnel lantern (pronounced frəˈnɛl or fruh-nel ) is a common lantern used in theatre that employs a Fresnel lens to wash light over an area of the stage . The lens produces a wider, soft-edged beam than a spotlight or key light , and is commonly used for back light and top light. The distinctive lens used in a Fresnel lantern

3445-771: The receiving, male jack (IN). Cabling for DMX512 was removed from the ANSI E1.11 standard and a separate cabling standards project was started in 2003. Two cabling standards have been developed, one for portable DMX512 cables (ANSI E1.27-1 – 2006) and one for permanent installations (draft standard BSR E1.27-2). This resolved issues arising from the differences in requirements for cables used in touring shows versus those used for permanent infrastructure. The electrical characteristics of DMX512 cable are specified in terms of impedance and capacitance, although there are often mechanical and other considerations that must be considered as well. Cable types that are appropriate for DMX512 usage will have

3510-554: The relative lack of control, when compared to an ellipsoidal , is a major disadvantage. The distinctive soft beam of a fresnel can make it very useful as a special in certain situations. While the focus can alter the size of the beam, the distinctive scatter of light that the Fresnel lens emits also requires a way of controlling its shape. Since Fresnels cannot use internal shutters, such as those found in an ellipsoidal spotlight, they are often fitted with distinctive barn doors to control

3575-532: The rest absorbed by the casing as waste heat . The degree to which the lamp may be focused is limited by the length of the housing. To reduce the width of the beam, the lamp and reflector are moved further back from the lens (spot focus). However, the farther back in the housing the lamp is placed, the more light is wasted in the housing. In the theater and dance world, Fresnels are most often used for top or backlighting, at medium throw distances. In small venues, they are occasionally used for front light, although

3640-434: The same orientation repeatedly.) Several models are available which can hold two patterns simultaneously, and may allow patterns to rotate separately or in opposite directions. The iris is a metal frame housing designed with an adjustable shutter assembly (an iris ). The iris is placed inside fixtures through a specifically designed opening, the accessory (or iris) slot. The iris is placed inside focal plane of fixture, before

3705-473: The same slot as a gel frame. Doughnuts are typically used in fixtures in order to sharpen the beam when a template is in place. A color scroller, color changer, or "scroller" is a lighting accessory used to change color gels on stage lighting instruments without the need of a person to be in the vicinity of the light. It is attached in the gel frame holder on the outside of a lighting instrument, immediately in front of lens assembly. The "scroll" of colours inside

3770-463: The spill and shape the beam of light. These are large metal flaps that may be mounted just beyond the color slot at the front of the lantern. They are colloquially known as "Harris Flaps" in the United Kingdom theatre industry. DMX512 DMX512 is a standard for digital communication networks that are commonly used to control lighting and effects. It was originally intended as

3835-450: The standard this way to provide the greatest design flexibility. Because of this, however, it was difficult to design receivers that operated over the entire timing range. As a result of this difficulty, the timing specification of the original 1986 standard was changed in 1990. Specifically, the MAB, which was originally fixed at 4 μs, was changed to 8 μs, minimum. The E1.11 (2004) standard relaxed

3900-418: The standard. Other form-factors of connectors are permitted on equipment where the XLR and RJ-45 would not fit or are considered inappropriate, for example on equipment intended for permanent installation. From ANSI E1.11 - 2008 section 7: 7.1.2 Concession for use of an alternate connector (NCC DMX512-A) A concession to use an alternate connector is available only when it is physically impossible to mount

3965-569: The start of another, causes receivers to start reception and also serves as a frame (position reference) for data bytes within the packet. Framed data bytes are known as slots . Following the break, up to 513 slots are sent. The first slot is reserved for a "Start Code" that specifies the type of data in the packet. A start code of 0x00 ( hexadecimal zero) is the standard value used for all DMX512 compatible devices, which includes most lighting fixtures and dimmers. Other start codes are used for Text packets (0x17), System Information Packets (0xCF), for

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4030-407: The transmitter and receiver timing specifications. This relaxed the timing requirements for systems using controllers built to DMX512-A (E1.11); however, a significant number of legacy devices still employ transmit timing near the minimum end of the range. Maximum times are not specified because as long as a packet is sent at least once per second, the BREAK, MAB, inter-slot time, and the mark between

4095-433: The use of cable following analog audio specifications for DMX, which can lead to signal degradation and unreliable operation of the DMX network. DMX512-A (ANSI E1.11-2008) defined the use of eight-pin modular ( 8P8C , or "RJ-45") connectors for fixed installations where regular plugging and unplugging of equipment is not required. Note: Several manufacturers used other pinouts for RJ-45 connectors prior to this inclusion in

4160-429: The use of one of the twisted pairs. The second pair is undefined but required by the electrical specification. The E1.11 (DMX512 2004) electrical specification addresses the connection of DMX512 signal common to earth ground. Specifically, the standard recommends that transmitter ports (DMX512 controller OUT port) have a low impedance connection between signal common and ground; such ports are referred to as grounded . It

4225-465: Was the three-pin XLR connector (also called cannon jack in some countries). When DMX512 was ratified, many of these manufacturers then issued firmware updates to enable the use of DMX512 control on their existing equipment by the use of a simple adapter to and from the standard 5-pin XLR style connector. As the electrical specification currently only defines a purpose for a single wire pair, some equipment manufacturers continue to use it. Such equipment

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