By experience I have got to know that the cable normally used to drive Led strips (22AWG) is not good anymore if it is longer that 10 meters.
I realized this while working with 5 pieces of 2 meters of WS2812b where all of them are several meters apart from the Arduino board that I use to control them. In that case, I was sending the same program to all of them, and what I did was to connect all of them to the same pin, and it didnt work at all. The sum of the lenght of all 10 cables was much longer than 10 meters, and the signal got lost.
While searching for a solution, I discovered a post by Teknynja (http://www.teknynja.com/2014/02/driving-ws2812neopixels-rgb-leds-over.html?m=1) where it is explained how to use SN75176 to be able to drive WS2812b on cables much longer than 10 meters. I did the experiment myself, and even though he uses CAT 5 cable, I was able to succesfully send signal over 50 meters of 22AWG cable.
After that, I used SN75176 not to use longer cables, but to split the signal from the output pin into 5, and then I could connect 22AWG cable to drive each piece of led strip apart from the board some 10 meters each. (images of the board at the bottom of the post)
so far, so good.
Now I was trying to drive 4 pieces of 2 meters of WS2812b that are some 8 meters away from the arduino board, and again they are all displaying the same program out of a single arduino pin. So I connected a 8 meters long 22AWG cable to the arduino, which is inside of the restraints previously mentioned, and at the end of this cable I connected one of my "splitter board", to send the signal to the 4 Led strips. It didnt work.
I have the feeling that the SN75176 do the job only if it is connected close from the arduino board, but if there is already a lenght of cable between the pin and the driver (SN75176) the signal is already weak enough or noisy enough for the SN75176 to manipulate it properly.
I of course did a lot of try outs in different circumstances, different cables, lengths and a large list of etceteras, but I dont think it is worthy to post them here. Perhaps with the information already provided, some of you already has an idea on how to sort out these problems. How do you drive ws2812b over long distances?