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  • DMX Over Cat5

    In general, ETC follows the ESTA Color Code for termination of DMX512 on Cat5 cabling:

    ETC IDC
    Connector Position
    Wire Color Function Equivalent
    XLR Pin Number
     1 white / brown Data link common (common reference) for Pair 1 (0 V) 1
     2 orange Pair 1 complement (Data 1 -) 2
     3 white / orange Pair 1 true (Data 1 +) 3
     4 brown Data link common (common reference) for Pair 2 (0 V) 1
     5 green Pair 2 complement (Data 2 -)
     4
     6 white / green  Pair 2 true (Data 2 +)
     5
     7  blue Unassigned
     8 white / blue
    Unassigned 

    Note: some ETC products use a single 8-position header for both DMX IN and DMX THRU.  In that case, the first three positions are used for DMX IN and use white / brown, orange, and white / orange; the next three positions are used for DMX OUT on a different cable, and again use white / brown, orange, and white / orange.  Refer to the ETC Setup Guide - Cat5 Cable Preparation for IDC Termination for more information.


    For DMX over CAT 5, there are several things to note.  Per ESTA's DMX512 Over Category 5 Cable Summary ( http://tsp.esta.org/tsp/working_groups/CP/docs/DMXoverCat5_Summ.pdf), Cat 5 UTP (Unshielded Twisted Pair) and STP (Shielded Twisted Pair) cable is acceptable.  They are careful to note (in ANSI E1.27-2 – 2009 (R2014)) specific installation parameters for permanently installed cables. 

    "Cables should be protected against physical damage along their entire length [and] may include conduit, trunking, or raceways."

    ETC prefers to have UTP, STP and FTP installed in grounded metal conduit for purposes of additional data integrity and physical protection.  

    ESTA does not define a maximum run length for DMX over Cat5 since many factors will affect the maximum run length such as number of devices, number of splices in the cable, the strength of the DMX transmitter(s), if Remote Device Management (RDM) is being used, and sources of interference.  ESTA does state (again, in ANSI E1.21-2):

    "A properly selected and installed DMX512 cable should provide acceptable signal strength for runs of 300m (1000ft).  Please note that the technical requirements, such as run-length and topology for other networking technologies, such as Ethernet, should be considered if using the installed cable for another networking technology in the future is anticipated."

    Cat5 or equivalent is not preferred as a portable cable since it is not as rugged as other DMX cables.  Male RJ45 connectors are especially prone to breakage over repeated re-connections.



    Suggested Wiring Practices

    • Do not run data signals next to or in the same conduit as high power sources.  If necessary to be near these sources cross over them at 90 degrees or keep as much parallel distance between them as possible.
    • Use IDCs for all Category 5 cable applications.
    • Run in grounded metal conduit when there may be concern from nearby high power devices and/or situations where the structure of the cable may be compromised.
    • Plenum cable in plenum applications and also where physical damage may be a concern and conduit is not practical.
    • Be aware that the Color Kinetics uses a different (non-ESTA standard) color code.

    Background Information

    From the ESTA report:

    Conclusion

    Data obtained from all three of these test sessions confirms that, in most respects, UTP and STP Category 5 cable can be expected to perform at least as well as EIA-485 rated data cable for DMX512 applications.

    It is also important to note that ETC prefers that CAT 5 terminations be performed with IDC (insulation displacement connectors) devices.  These can be, for example, headers specifically designed for the size of conductor or RJ45s.  Stripping the wire and then placing it in a solder cup or screw terminal is an easy invitation to conductor breakage.  This is why we offer an alternative IDC header to support CAT5 wire on most of our DMX products.

     

    Also from ESTA:

    ANSI E1.11 - 2008 (R2013), Entertainment Technology - USITT DMX512-A - Asynchronous Serial Digital Data Transmission Standard for Controlling Lighting Equipment and Accessories CP/2007-1031r3.1:

    7.3 IEC 60603-7 8-position modular connectors

    The use of IEC 60603-7 8-position modular connectors (commonly referred to as RJ45 type connectors - plugs/jacks) and associated punchdown terminal blocks shall be limited to connections that are part of a fixed installation and not normally accessible except to qualified, authorized users, nor intended for regular connection and disconnection.  External (user accessible) IEC 60603-7 8-position modular connectors are permitted only on patch and data distribution products and only when permanently installed in controlled access areas.

    Note: Examples of not normally accessible or controlled access areas include a locked electrical room or control booth, provided those who need access have a key (or lock combination) available.

    Table 4 - Connection Schedule for DMX512 equipment using IEC 60603-7 8-position modular connectors

    Pin (Wire) # Wire Color DMX512 Function
    1 white / orange data 1+
    2 orange data 1-
    3 white / green data 2+ (optional)
    6 green data 2- (optional)
    4 blue Not assigned
    5 white / blue Not assigned
    7 white / brown (Common Reference) for Data 1 (0v)
    8 brown (Common Reference) for Data 2 (0v)
      drain  

    Note 1: Pin numbering and color in accordance with ANSI/TIA/EIA-568 scheme T568B.

    Note 2: Pin 8 should be wired as signal common even if pins 3 and 6 are NOT wired so that both conductors 7 and 8 are at equal potential.

    Warning:Accidental connection to non-DMX512 equipment likely to be encountered (e.g., an Ethernet Hub at a patch bay) may result in damage to equipment. Pins 4 and 5 may carry voltages outside the EIA-485 range in telecom applications (e.g., telephone ringing). Pins 4 and 7 may carry voltages outside the EIA-485 range in other applications (e.g., some manufacturers whose distributed DMX512 buffering products require low voltage DC power may use these wires for this purpose). Because of these various uses, misplugging unlike systems could cause serious damage.


    Color Kinetics

    It is important to note that the Color Kinetics wiring is completely different than the ESTA standard.  To the best of our information, CK uses the following:

    Pin (Wire) # Wire Color DMX512 Function
    1 white / orange data 1-
    2 orange data 1+
    3 white / green common
    4 blue Not assigned
    5 white / blue Not assigned
    6 green Not assigned
    7 white / brown Not assigned
    8 brown Not assigned

    So while the color codes for pin 1-3 are the same, the signals are all different.