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which USB to 485 converter?


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I was going to run my network from the extra 485 port on my server.... that was till the 485 to 232 circuit died on my HVAC zone controller...

so now I need to get a USB to 485 converter for the light show.. but I see there are different ones at LOR... how do I know which one I need?

im going to have 11 controllers on the network... 2 on the first floor roof and then the other 9 in the yard...

the 2 on the roof will be about 10 feet from each other and those 2 will be about 60-75 feet max from the next unit in line.... so will i need the Boosted converter or the regular? I'll be using Cat-5e wire for the network...

should I ground the unused pairs? (this my first year with LOR.. i ran AL before and never grounded the unused wires....


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With controllers only and no ELL's, any of the USB interfaces will work for you. Unless you're planning to add ELL's, I'd simply use the cheapest one (which is the one I ordered for this year to replace my old serial RS232 one).

The old serial one had a limitation of no more than 100' from the computer to the first controller, but since USB provides power to the newer interfaces, there are no such restrictions. You can have hundreds, probably 1000 or more, feet between any pair of controllers.

You don't need to ground anything, just plug in the wires and leave the one at the end empty.

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eldoradoboy wrote:

in my wildest dreams of convincing my fuddy duddy neighbors of joining the show would i ever get to add ELL's.....

Right there with you in the same boat. Ours won't speak to us 24/7/365 because we (gasp) put up Christmas lights and they don't like them. They tried to rally neighborhood support to shut us down, but much to their chagrin, the rest of the neighborhood likes the display...

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I agree that any of the three should work for you. I actually use all three.

I use the USB-485 for testing and portable work, as it fits easily in my laptop bag.

My go to box is the USB-485B. In theory it has a faster turn around time, for more efficient use of the 485 network when doing interactive triggers. In practice, they still today are apparently pretty similar. It also has the dual connectors on it, so you can put it in the middle of a run, essentially running cables from one port to one side of the yard, and the other port to the other side of the yard. I also like that if I am doing some DMX testing, I can plug in one of the USB-485B adapters, then the iDMX, and the adapter will power the iDMX.

Then we also ordered one of the USB-485-ISO adapters, for the part of the city show that is on a separate utility feed from the show computer. We have not had issues in the past, but we consider this to be a proactive step to avoiding issues. I like that it has power status lights, and TX/RX lights. In theory, it may also help avoid lightning damage to your show PC, if one of your controllers, or display lights are hit. It certainly won't guarantee your PC won't get damaged, but I suspect it will enhance the odds of the PC coming through OK.

As for the grounds, I thought that the AL cards tied all unused pins to local ground at every controller. LOR leaves the unused pairs alone. The PC cards pass through the unused pins, but not all the controllers do. As far as I can tell, the signal ground is not tied to the local ground in any of the controllers, and is only tied to the one ground wire in the cat5. Nobody that I am aware of has found any need to ground the extra wires in the LOR cabling.

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