Behringer EUROLIGHT LC2412 Manual - Page 20

20 EUROLIGHT LC2412 User Manual 8. Dimmer Control 8.2 Digital control via DMX512 Dimmerpack DMX512 output DMX512 input LC2412 rear 0-10 V switch box Analog output 0-10 V Analog input Tape/Send output 8.2.1 Digital control features The EUROLIGHT LC2412 features a modern digital interface according to the DMX512 Digital Data Transmission Standard For Dimmers And Controllers, that was established in April 1990 by the USITT Engineering Commission (United States Institute for Theatre Technology, Inc.). Since virtually all modern equipment uses this standard (even if it is done with partially different plug-in connectors), your EUROLIGHT LC2412 is therefore extremely flexible in how it can be implemented. A big advantage of digital control is its enourmously simplified cabling, since you only need one single cable for transmitting control data. This sets the DMX system apart from its analog conterparts, which need an extra control cable for each individual channel. Another big advantage is made possible by the freely addressable receivers, which is done by menas of software. You can therefore save yourself from having to painstakingly lay cables each time you wish to assign a particular dimmer to a different channel. Additional information on this subject can be found in chapter 8.2.2. Mirror ball PRO MIXER VMX200 Fog machine (with 0-10 V interface) Fig. 8.1: Standard wiring in combination with a dimmer (analog and/or digital control) 8.1 Analog control In addition to the modern DMX512 interface, you can control your EUROLIGHT LC2412's dimmers using the conventional analog outputs (ANALOG OUT (57), 0 - 10 V DC). However, this lets you control only twelve dimmer channels plus two special channels (only "0 Volts" or "10 Volts"). ◊ Whenever possible, use a multicore cable to connect your LC2412 to the dimmer rack, and apportion the cable to individual dimmer packs only once the cable reaches the rack. 8.1.1 Controlling analog dimmers via DMX512 What at first seems like an error is in reality a very useful feature: By using a so-called demultiplexers (demux), you can convert digital commands into analog and therefore control your analog dimmer packs. The advantage of such a configuration is apparent: you can address the demultiplexer freely, that is, it can for example begin with channel 12 and therefore convert control commands from console channels 13 - 24 into analog signals (DMX channel 0 is controlled one-to-one by console channel 1 and so on, hence the numbering offset). Furthermore, you need only short multicores for analog control, since you can arrange the demultiplexer near the dimmers and send control commands via a single DMX line. Interface format (EIA-485) The DMX512 standard uses the RS485 interface standard for data transmission, well-known for its impunity to interferrence. The data are serially transmitted in the asynchron fashion at a transmission rate of 250 kBit/s, successively for each of the connected dimmers (up to 512 channels). The more dimmers are connected, the longer the time interval until the next command on this channel. ◊ It is advisable to limit the number of deployed channels in order to ensure a maximum refresh rate. Therefore, do not use more channels than you actually need. In combination with the DMX512 standard, you can run up to 32 loads on a single sender (LC2412). One load responds to one DMX512/RS485 receiver, for example, the way it is implemented in a dimmer pack. If you wish to run more than 32 loads, we recommend using level translaters and/or signal splitters. 8.2.2 Assigning DMX channels (Softpatch) Softpatch means: you can assign up to three freely selectable DMX channels to a console channel. ◊ Each of the DMX channels can be assigned to only one fader. Otherwise, contradicting commands would be given with various fader settings. To make the capabilities of the DMX512 as well as the capabilities of the LC2412 transparent, we have to draw a clear distinction between three different kinds of channels: Console channels The channels of your LC2412 (= 24+2 channels) are 26 routes through which you can send commands. This in no way means that you can only control 24 lighting elements. Dimmer channels (Dimmer Loops) Dimmer packs represent the power section of a light control system, comparable to power amplifiers of a PA installation in the audio field. Each dimmer channel is assigned to one DMX channel, that is, it can receive commands from only one channel. For example, if a dimmer loop can handle a maximum power rating of 2.3 kW, you can connect several lamps, spotlights and similar (e.g. 4 x 500 W).