erratic CCR behavior

[rickswa]

Hello All,

This is my first year switching from LOR to xlights and also using the Falcon F16v3 for my main controller.  I have 1 universe setup for 15 LOR AC boxes and another for 2 CCR trees that I have and then additional universes for 4 pixel arches from the f16 outputs.  For some odd reason even though I have the macros disabled on the CCR controllers, I had to make the second CCR start channel a few channels after the 1st one ended to make it behave normally.  I tested them earlier this year with one arch and 3 LOR AC boxes hooked up to the f16 and all was perfect after figuring out that channel assignment issue.....

Fast forward to today when I finally got my display ready to run.  I have the CCR's set to serial output 2 and the AC boxes on serial output 3 and all defined properly in xlights.  If I have only 1 CCR hooked up, it works perfect.  But if I plug another cat 5 cable into the CCR controller, even if it is not hooked up to anything at all, I get a serious lag, erratic behavior (sometimes CCR doesn't come on at all when it should, other times part of it lights up when the whole thing should, etc).  As soon as I unplug the cable that would go to the second CCR, it's back to working perfect.  I've tried both CCR controllers and both do the same thing.  I've tried 6 different cat 5 cables from the f16 to the PC I use, from the f16 to the ccr's and between the ccr's and same results every single time.  I just cannot understand what would cause this even when I just plug a cable into the second jack when it's not connected to anything.  It's baffling that it worked when I tried it with part of my AC boxes set up earlier this year but now I can only have one CCR hooked up for it to work properly.  The rest of the display works perfect, it's just this CCR issue.  Any ideas what could be causing this?  Thanks for any help.

[k6ccc]

You are likely seeing an issue caused by not terminating the RS-485 network.  Properly, any RS-485 network should be terminated at both ends of the network.  MOST of the time we lighting people can get away with not doing so.  This would be more pronounced if the cables are long.  Different types or number of devices, cable lengths, quality of cable, network speeds (although I realize the DMX always runs at the same speed, but that's not the case for LOR networks), will all effect signal propagation.  Leaving a cable just hanging there at the end of the network is asking for trouble.   Build up a proper termination and the problem will likely go away.