Daisy chain

[Dan Williams]

when daisy chaining multiple controllers is it okay to use phone cable or should i stick to cat 5. I currently have one controller connected to pc via cat 5 and I'm looking to buy a couple other controllers and wanted to know from those who are experienced, the best way to go.

thanks in advance

[Dave Batzdorf]

I have used only cat-5 cable. I think it would be a better product for longer distances and possibly hold up better in the elements.

[Dale J]

i would agree, other than possibly the cost of the cat 5 cable. i think it works much better. Also be sure if you mix them that you use the proper jacks it makes a difference of which in and out jacks from one controller to the next you use if mixing phone and cat5 cables,

[JBullard]

Some swear phone cable works just fine, others swear at phone cable.

Your success may depend on cable distance, cable management with power carrying cords, and many other factors unique to each display.

CAT5 cords are the cheapest part of my display, and the last thing I need during a hectic set up, is trying to diagnose communication problems from trying to save a few cents on wire. (I tried, phone cable is NOT reliable in my display)

If you do choose to use phone wire, it must be 4 conductor, cross wired. Verify before trying to use, some is only 2 conductor, and some longer lengths are made for extension use, and are not crosswired. and as mentioned above, use the proper jacks.

[beeiilll]

You could water down the gas in your car and it might still run, but why would you?

Use Cat5 and save yourself a "possible" headache later on. Comm problems are not fun to troubleshoot and can be intermitten as well.

As far as the price for Cat5 cable, go here to buy whatever you need. These are some of the best prices going for pre-built cables. I bought a bunch of them so I have spares just in case I screw one up during takedown.

http://www.monoprice.com/products/subdepartment.asp?c_id=102&cp_id=10208

Just my 2 cents worth (although I saved more than that by getting them from monoprice ).

Bill

[beeiilll]

Sorry for the double post. ISP burped!!!

Bill

[Dan Williams]

thanks for all your advice.. I'll check this off my design list

[Max-Paul]

Jeff,

I think for myself, I'll use the Cat5 (e) or 6. From my days in electronics and Amateur radio. The twist will help with any stray noise. Course shielded cable will go further in reducing noise, but so will cable placement. As long as I do not lay the wire side by side with either the supply power cable or the wires going out to the lights. The noise will be minimized. And like wise not routing the comm cable beside the AC leads, the noise will be reduced. And crossing the AC line at right angles does not induct noise onto the comm cable. Many people do not take these cautions and have had trouble with noise spikes on their comm cables.
But I regress, there are times that for a short distance running parallel does not do any harm. Just try to minimize it to the shortest distance as possible. And put as much distance between the two wires is best if you do have to run them parallel

Max

[Steven]

Jeff Millard wrote:

Unless you choose to use the third set of wires (1 and 2) for a feed through loop to an alarm, the other 4 wires in Cat5 are unused.

I use one of the unused pairs to run audio to outdoor speakers (through an ad hoc system similar to a constant voltage speaker system).

[Tim Dorr]

Jeff Millard wrote:

There is little or no difference in the wire if it's solid other than the fact that Cat5 has the pairs twisted.

Agree Jeff, that there is little difference in the wire between a phone cord and Cat5, performance wise when hooking controllers together. And I used phone cord for my first three years using LOR. But last year I ran into a problem and tracked it down to using phone cord.

There are three data receptacles in a controller. The left is "In Phone." The middle is Cat5 "In Data." And the right is "Out Phone" or "Out Data." It was the "Out" receptacle that caused me trouble because it will accommodate a Cat5 plug, which is a little bigger than a phone cord plug. The phone cord plug in the "out" receptacle can be a little loose, and not make the proper contact. It has to sit in there just right or you loose the connection to the next controller. When that happened, I replaced the phone cord with Cat5 and no more problem. So this year I'm going with 100% Cat5 so I remove one more thing to troubleshoot.

And for the Cat5 cost at monoprice.com, it was an easy decision for me.

[-klb-]

Comparing cabling for RS-232 and RS-485 is like comparing fuel properties for gasoline and diesel engines... RS-232 is ground referenced, while RS-485 is differential.. The primary reason for and benefit of differential signalling is that it allows for increased noise immunity when using twisted pair cabling..

RS-232 is a serious stretch to take to 100 feet... RS-485 can fairly easily be taken to 4000 feet, at faster data rates than RS-233.. For applications that need RS-232 at distances over 100 feet, the usual approach is to convert to/from RS-485 and twisted pair for the long haul..

Consider that both LOR and DMX use RS-485 for the electrical specification. Using phone cords with LOR is very much like using microphone cord for DMX...

Here are three references for RS-485, all of which reference twisted pair wiring:

http://en.wikipedia.org/wiki/RS-485

http://www.interfacebus.com/Design_Connector_RS485.html

http://www.national.com/an/AN/AN-1057.pdf

Here is one more that doesn't actually spell it out, but references it in a way that pretty much takes twisted pair for granted. However, it appears to be one of the best articles on ways to make RS-485 reliable...

http://www.circellar.com/library/ccofeature/perrin0799/index.asp

Phone cord will probably work just fine, most of the time, for most small displays. However, if you have gone beyond the level of just a home display were outages and troubleshooting time don't matter, I really think Cat 5 is the way to go.. If you are being paid to do a show, or have tens of thousands of dollars of city funds invested in equipment, you don't have the luxury of learning if phone cord will work in your application by trial and error.

[Max-Paul]

Thanks KLB,

You have stated much better what I was trying to say, and keep it simple.



Max