Periodically the question comes up whether you can run DMX over Cat5 cable.
FACT:
You can use Cat 5 for DMX both Shielded Twisted Pair (STP) and Unshielded Twisted Pair (UTP) are acceptable.
ESTA RESULTS REGARDING UTP:
"Investigation - Radiated Signal Tests
...Until we are able to perform free field radiation measurements to ascertain conformity with the various national standards regarding acceptable levels of radiation it would be best to limit the use of Category 5 UTP for DMX distribution to “in conduit” only installations and avoid the use of Category 5 for free air interconnections."
"Investigation - Induced Immunity Tests
Pulses were induced on the cables both inductively and capacitively. No plots were made. The
performance of DMX equipment was observed, and no adverse results were noted."
RJ45 PINOUT
http://www.usitt.org/DMX512FAQ.aspx#a9
TRADITIONAL (not Cat5) CABLE OPTIONS:
A "to spec" DMX cable is a shielded, Low Capacitance, 100-120 Ohm cable.
http://www.usitt.org/DMX512FAQ.aspx#a6
A premade DMX patch cable runs about $1 per foot online (new) and they are cheaper yet on ebay. This is what I use professionally and personally. A DMX patch cable is more expensive then Cat5. However a “to spec” DMX cable will last a lifetime and the best part is they are ready to used out of the box.
BEST PRACTICE
Regardless of your cable choice always terminate at the last dimmer pack with a 120 resistor soldered between the data pins (2 and 3 on a standard 5pin XLR).
Great Read: http://www.usitt.org/bookstore/go.php?to=ItemDetail&sku=R60
UPDATED: Aug 16, 2009
I updated this post to retract some incorrect information. Previously it was my understanding that UTP must be run through grounded metallic conduit to protect from induced interference. After reexamining the ESTA test results this appears to not be the case.
FACT:
You can use Cat 5 for DMX both Shielded Twisted Pair (STP) and Unshielded Twisted Pair (UTP) are acceptable.
ESTA RESULTS REGARDING UTP:
"Investigation - Radiated Signal Tests
...Until we are able to perform free field radiation measurements to ascertain conformity with the various national standards regarding acceptable levels of radiation it would be best to limit the use of Category 5 UTP for DMX distribution to “in conduit” only installations and avoid the use of Category 5 for free air interconnections."
"Investigation - Induced Immunity Tests
Pulses were induced on the cables both inductively and capacitively. No plots were made. The
performance of DMX equipment was observed, and no adverse results were noted."
RJ45 PINOUT
http://www.usitt.org/DMX512FAQ.aspx#a9
TRADITIONAL (not Cat5) CABLE OPTIONS:
A "to spec" DMX cable is a shielded, Low Capacitance, 100-120 Ohm cable.
http://www.usitt.org/DMX512FAQ.aspx#a6
A premade DMX patch cable runs about $1 per foot online (new) and they are cheaper yet on ebay. This is what I use professionally and personally. A DMX patch cable is more expensive then Cat5. However a “to spec” DMX cable will last a lifetime and the best part is they are ready to used out of the box.
BEST PRACTICE
Regardless of your cable choice always terminate at the last dimmer pack with a 120 resistor soldered between the data pins (2 and 3 on a standard 5pin XLR).
Great Read: http://www.usitt.org/bookstore/go.php?to=ItemDetail&sku=R60
UPDATED: Aug 16, 2009
I updated this post to retract some incorrect information. Previously it was my understanding that UTP must be run through grounded metallic conduit to protect from induced interference. After reexamining the ESTA test results this appears to not be the case.
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