Cat 5 Maximum lenght to connect 16 channel controller

[Lincoln Lights]

I have a 3 year old 16 channel residential controller.  I connect from a USB communication port (RS 485).  I read in the manual that a serial port has a maximum length.  Does CAT 5 usb device have a maximum length?

 

Why do I ask?  Well here is the problem I am having.  This years design requires I place my show computer in a location that requires me to run about 150 ft of cat 5 cable.  (Now this was my last piece to install in my show, so I did not have that much riser cable left, but I had to long long pieces of riser left and ran them threw the ceiling tiles to my exit point  from the building.    I coupled them together at an access point.  When I connected my controller, LOR hardware did not find the controller.  However, when I connected the controller at the access point, it worked.  I extended the cable with a coupler with a 10 ft section of cat 5, and it did not work.  I connected with just the 10 ft section of cat 5, and it worked.  I tried many different couplers, and no change. 

 

ANy clues on why this is not working?  My conclusion is that I have to run either one continues cat 5 cable and you can not couple two together to gain length.  Which does not make since to me. 

 

 

Sean

[Lincoln Lights]

Never mind, just read data sheet on rs 485.  4000 feet capability.  So, does any one have a clue why when I couple two lines together it is not working.  Unless I have 5 bad couplers...  None of which show any signs of any issues.

 

 

Sean

[TripleJ3EB]

I've used couplers before, as long as they are straight thru, they should work fine.  Is your short cable a cross-over cable?  Make sure the wires in the plug at both ends of the cable are identical.

[Don]

To me anytime you use a coupler you are simply adding one more possible point of failure along the way. If possible, I would make it a direct run.

 

If that's not possible, then go check the couple and cables. 

[k6ccc]

Did I understand that you used a WiFi access point as coupler? If so, that's your problem. Although both LOR and an Ethernet LAN use common Cat-5 cable, they are NOT compatible - and in fact risk damage to one or the other.

[Max-Paul]

Shame so many people do not read and understand that this is RS-485 and is not compatible with Ethernet. Pray that you have not burnt anything out. Its like trying to put an automotive light bulb on a 110VAC wire. The bulb will burn up in a heart beat. The voltages are not the same for RS-485 and Ethernet. Go and see if Radio Shack or any place that sells all of the little things that work with networks. Tell them you want a simple little passive coupler to make two patch cords longer. As long as you have two cords  (Patch) that work. Then the coupler should work too.  Good catch Jim. I was thinking Access Point as some fancy way of saying junction box.

[Gordon Starr]

Can anybody tell me the max length of 485 cable to run between 2 CMB24 contollers?  I'm running 50 feet of Cat 5 and having problems with controller #2 when I upload my sequence into controller #1 and let it run the show.  If I run it from my computer using the USB-485 dongle, I don't have a problem. Only when the sequence is uploaded to the controller.

[k6ccc]

The spec is 4000 feet total length for RS-485.