A SIMPLE DMX512 CONTROLLED DIMMER SYSTEM

Transcription

1 UP TO 1000 OHM DATA CABLE TERMATOR A SIMPLE DMX512 CONTROLLED DIMMER SYSTEM (WHAT DMX512 WAS DESIGNED TO DO) 1

2 MAXIMUM CABLE LENGTH FROM CONSOLE TO TERMATOR IS 1000 CABLE SHOULD BE OHM LOW CAPACITANCE DATA CABLE. COLOR SCROLLERS TERMATOR ALL DEVICES ON A DMX512 LK ARE CONNECTED A DAISY CHA. THE PUT OF ONE FEEDS THE PUT OF THE NEXT. A CABLE FAILURE ANYWHERE ON THE LK CAN BRG THE ENTIRE SYSTEM DOWN. AN A.C. FAULT ONE OF THE DIMMERS CAN BLOW UP EVERY PIECE OF EQUIPMENT ON THE DMX512 LK: CONSOLE, SCROLLERS,, ETC. DEPENDG ON THE PRODUCT DESIGN, AS FEW AS 5 DEVICES MAY OVERLOAD THE CONSOLE S ABILITY TO DRIVE THE SYSTEM. SOME LIMITATIONS OF THE ORIGAL DMX512 SPECIFICATION 2

3 EACH PUT OF THE CAN DRIVE 1000 OF OHM DATA CABLE THE CONSOLE CAN DRIVE UP TO 1000 OF OHM DATA CABLE TERMATOR SOME S HAVE "" CONNECTORS. THESE SHOULD BE USED ONLY TO CONNECT TO ANOTHER WITH A CABLE. IF NOT USED, THEY MUST BE TERMATED. UNUSED PUTS DO NOT NEED TO BE TERMATED EACH PUT OF THE CAN DRIVE MANY DEVICES TERMATOR COLOR SCROLLERS TERMATOR S WERE VENTED TO OVERCOME SOME OF THE LIMITATIONS OF DMX512. A CABLE FAILURE ON ONE PUT CANNOT AFFECT THE DEVICES ON ANOTHER PUT. A WELL DESIGNED WILL PROTECT AGAST AN A.C. FAULT ONE OF THE DIMMERS CAUSG DAMAGE TO OTHER EQUIPMENT. DATA ERRORS CAUSED BY A FAULTY DEVICE ON ONE LK WILL NOT AFFECT THE DATA TEGRITY ON THE OTHER PUTS. AUTOMATED LIGHT FIXTURES TERMATOR TERMATOR S SOLVE SOME DMX512 PROBLEMS 3

4 THIS LE CAN BE 1000 LONG SOME S HAVE OHM PUTS SO NO EXTERNAL TERMATOR IS REQUIRED. PUT IT IS A GOOD IDEA TO PLACE EACH DEVICE "TYPE" ON A SEPERATE PUT. THE MAXIMUM NUMBER OF DEVICES ON EACH PUT DEPENDS ON THE DESIGN OF THE DEVICE S PUT CIRCUIT. EACH PUT CAN DRIVE AT LEAST 32 DEVICES IF THE DEVICES ACTUALLY MEET THE DMX512 SPECIFICATION. SOME DEVICES WHICH CLAIM DMX512 CAPABILITY DO NOT ACTUALLY MEET THE SPECIFICATION SO FEWER THAN 32 DEVICES MAY OVERLOAD AN PUT. THE ONLY WAY TO BE CERTA IS TO CHECK THE MANUFACTURER S LITERATURE OR MANUALS. MOST QUALITY S CAN BE DAISY CHAED (THE PUT OF ONE FEEDG THE PUT OF THE NEXT). THIS ONE IS BEG USED TO EXTEND THE CABLE LENGTH. TERMATOR THIS LE CAN BE 1000 LONG. PUT THIS LE CAN BE 1000 LONG. EACH OF THESE LES CAN BE 1000 LONG PUT PUT TERMATOR TERMATOR TERMATOR TERMATOR S SOLVG SOME MORE CHALLENGES HERE A IS BEG USED AT THE DIMMERS TO PREVENT A.C. FAILURE ONE DIMMER FROM BLOWG UP THE OTHER DIMMERS. HERE A IS BEG USED TO CREASE THE NUMBER OF DEVICES BEG DRIVEN. ALSO, PERHAPS, TO SIMPLIFY WIRG AND EXTEND CABLE LENGTH. TO 20 MORE FIXTURES TO 20 MORE FIXTURES 4

5 WHOOPS - DO NOT "TEE" OR "WYE" HIGH SPEED DATA CABLES WHOOPS - NO ISOLATION BETWEEN DIMMER AND CONSOLE (THIS ISN T REALLY A NO-NO BUT CAN RESULT DAMAGE TO THE CONSOLE SHOULD THE DIMMER FAIL). WOOPS - NO TERMATOR BELDEN 8412 CABLE WHOOPS - BELDEN 8412 IS A MIKE CABLE WITH A NOMAL IMPEDANCE OF 52 DMX512 SHOULD BE CARRIED ON OHM CABLE. AUTOMATED LIGHT ON DOOR TOWER WHOOPS - MORE THAN 1000 OF CABLE WITH NO BOOSTER WHOOPS - NO ISOLATION BETWEEN DOOR FIXTURE AND CONSOLE (THIS ALSO IS NOT REALLY A NO-NO BUT DOOR FIXTURES TEND TO PICK UP STATIC ELECTRICITY FROM STORMS WHICH CAN EASILY DAMAGE A CONSOLE. TERMATOR SOME DMX512 NO-NO S 5

6 DMX512 COMBE UNIT MANY COMBE METHODS ARE POSSIBLE RG, PATCHG, PRIORITY CONTROL BUT THE MOST COMMON IS HIGHEST TAKES PRECEDENCE (HTP) AKA "PILE-ON". TERMATOR MULTIPLE CONSOLES CAN CONTROL THE SAME LIGHTS WITH A DMX COMBE COMPUTER AC TERMATOR SGLE CHANNEL DMX RELAY PACK VAC SWITCHED VOLT HAZER OR PUT DMX TO ANALOG CONVERTER 0-10V CONTROL 0 TO 10 VOLT DIMMER PACK TERMATOR TWO CHANNEL DMX CONTROLLED SWITCH CLOSURE UNIT SWITCH CONTACTS SWITCH CONTACTS FORWARD SLIDE PROJECTOR REVERSE NON DMX DEVICES CAN BE CONTROLLED WITH VARIOUS ADAPTERS 6