Automated Fixtures Number of DMX fixtures

[sk8rsdad]

Not appreciably.

 

[Jay Ashworth]

Not likely. The frequency is too low for it to matter much what shape the traces are, and the resistance is likely microhms.

 

[RickR]

I haven't used a full load transceiver in the last 15 years - and those were all 5V DIP packages. There's no reason a new design wouldn't be a 1/8 unit or maybe a 1/4 unit load.

Please try to get that spec onto your device cut sheets. The marketing folks can make a point of putting more units on a run. I must rely on documented specs.

 

[JD]

Another factor is that whenever you have one of those connector boards with the feed off to the chip, you introduce a reflection point that can contribute to the noise on the line. As small as the area is, it breaks the impedance of the twisted pair. To a lesser extent, it is why you should use one 100 foot cable as compared to four 25 foot cables plugged into each other. Each time the line comes to a connector, the twisted pair line is broken, runs straight through the connector pins, and then resumes twits. No studies (that I am aware of) spec out what harm the connectors introduce, but anyone with an RF background (DMX is at heart an RF signal traveling through a transmission line) knows anything that disturbs the "transmission line" desegregates the signal. (Thus, the coaxial connectors in RF)