Daisy chain vs long single runs of Cat5 cable

[Andy Combites]

So this is an odd request. I'm building sever props for a high school marching band show. Each prop has a few hundred LED pixels. Each prop has it's own power source. Falcon F48 Board and then differential receivers on each prop. We need to be able to setup, perform the show, and teardown in 15 minutes. So when it comes to connecting the differential receivers to the F48, I can either run long, single cables out to each prop, or I could daisy chain them. If I daisy chain, I would have ethernet adapters that just facilitate the chain. One prop plugs into the next, and that plugs into the next, etc. So my question is this, has anyone had any problems with data degradation if you daisy chain smaller sections of Cat5 cable? Longer runs would be simpler, but for speed of setup, daisy chain would be faster setup. Thoughts?

 

[fasteddy]

Im no network guru but I don't think it should be an issue because a network switch will boost the signal and networks are made up of many network switches/routers which are basically daisy chained and distributed. The max distance you should run from cat5 is 100m (300ft) before you connect into a switch or router as its the length that degrades the signal

 

[Andy Combites]

Yeah, we'll be fine on the maximum run. These props will be on a U.S. football field, so the longest one would be about 100 feet total. I think I'm going to daisy chain the power and the data cables. Each prop has it's own Meanwell power supply, and we will have one, maybe two, generators/inverters that we can plug into. The overall goal is to be able to roll the props out, and quickly plugin the power and data cables, perform the show, and then quickly unplug and get off the field. And of course all of this setup and teardown will be done by the student performers. So we have to make it foolproof.

 

[algerdes]

I figure you already know that the F48 receives E1.31, but the 12 outputs are RS485. Also, the outputs are carrying 4 different signals in each cable. Though RS485 can be daisy chained, it is not a good thing - sometimes. Have you tried it?

 

[Andy Combites]

According to the wiring diagram at http://pixelcontroller.com/documents/F16V2 and Differential Expansions.pdf I can connect the 12 differential receivers to the F48 via Cat5 cables (yes, I know that diagram shows a different source for the receivers). And there can be 250' betweem the F48 and each differential receiver. I was just wondering if the performance would degrade if I had ten 25' sections of Cat5 connected with couplers.

 

[Jay.S]

A passive coupler is most likely not going to introduce any noticeable degradation of the signal. You are however introducing 10 weak spots into your cable. Do you really want that?

 

[Andy Combites]

Yeah, I know. It's about finding balance between strong power and data connections, and being able to have a quick setup without kids running around with long cables. We have four minutes to setup. Imagine a baseball grounds crew covering the infield when it rains, but with high school kids wearing band uniforms! Daisy chaining usually works best because one kids can take a cable snake that has the color-coded power and data cables, turns to their left, and plugs it into the next prop. Good news is Cat5 cable is cheap. We can try it with a daisy chain setup, and if it doesn't work, we can just have longer, single runs of cable. Thanks to everyone for your expertise.