AXLINK OVER CAT 5

Clingpeach wrote: »

Is this doable. Or not a good idea? Its for the new AMX Thermostats?

No problem on the data across one of the pairs - issue is power.

ryanww wrote: »

I used cat5 on one system I have because it was cost effective for them.. What I did is used the Orange pair for the AXP and AXM and then twisted the blue, green and brown wire and used that for positive 12v and the blue/wht, brn/wht and and green/wht for the ground. As long as you dont go over a couple amps, your fine. I wouldn't use it with anything over 4 amps.

The other issue is the voltage drop over the cable. You really cannot go very far. The official legth is something like 30 feet. I've inherited a system that was done in all CAT5. I'd love to slap the person who did it. They used some of the same run for IR, RS232 and AxLink. There is one run that has all this and power too. They all share a ground wire.

My advice is avoid using it if possible.

Clingpeach wrote: »

Thanks guys. Yes I see the issues which I dont want. Yet ANOTHER wire to be run in the house. Why this uses AXLINK I have no idea. What was the thinking behind this??

What does it matter?

a) you use Cat 5
b) you use certified AXLink cable

?

Clingpeach wrote: »

It matters because in trying to future wire a house you run tons of cat 5/5e or cat 6 cable. After NetLinx when was the last time you needed axlink wire

Well, Lutron uses that wire incidetally. It's the exact same wire.

Actually, Axlink is a great communication method. To be frank, I wish they'd use it for more things.

As for CAT5 and CAT6 and why or why not use if for other things...

It has a lot to do with the physics. single core wire is best used for AC and multi-stranded wire is best for DC. Technically standard networking is DC. But due to the fact that it operates in the MHZ or GHZ range, it tends to act a lot like AC.

I can tell you that elecrical engineers have migrains over how folks like us misuse wire. When we use the wrong wire for a job, there's no way to guaranty the performance. It's stuff like this that creates some of the flakiness of gear operation.

I've been in houses where I've seen speaker level over a couple strads of CAT5e. It was meant for network and telephone.

But, whatever gets the gig done I suppose...

For the data portion of Axlink, capacitance is the issue. For that reason CAT 5 cable is excellent. Since Axlink is mostly used these days for keypads which draw very minimal current, CAT 5 would work fine especially if you combine pairs for power as someone else suggested.

CAT 5 is not the right cable to use, but if you have to, no worries.

I think the real problem with Cat5 is the actual capacitance of the cable. Axlink likes about 15pf per foot.
This isn't an issude for short runs but it coulf really cause major issues on long runs.
Your digital 1's and 0's should be very square but with the wrong capacitance it could turn into more of an AC wave.
Professionally speaking I would use the proper cable.

An alternative is use CAT 5 for the data, and power it locally ... you only need to make sure the ground is common in that case. But that can get awkward too, and it's more than a pain to troubleshoot when the power is all over the place like that.

If you can run wire, I would, in this case. I generally use Lutron keypad wire for such jobs, since I always have tons of it on hand. I'm also to the point where I will run two Cat 5's and either a 4/18 shielded cable or 7/18 to any control location, whether I think I will need it or not.

Per the AMX Tech notes
http://www.amx.com/techsupport/techNote.asp?id=464

Liberty Wire and Cable, www.libertycable.com, and Comprehensive Video, www.comprehensivevideo.com,both sell cables specifically designed for use with a network like AXlink. Here are some features of these special-purpose cables:

one 22 AWG pair of separately-shielded, low-capacitance (12.5pF/ft) conductors for data. Low capacitance allows the data to travel further without degradation. Shielding reduces induction of noise from other sources, as well as emission of noise into susceptible nearby circuits.
one 18 AWG pair of conductors for power. Relatively high capacitance (35-50 pF/ft) serves to filter noise from the power source. The larger wire means reduced resistance, which allows for greater distances.

DHawthorne wrote: »

to the point where I will run two Cat 5's and either a 4/18 shielded cable or 7/18 to any control location, whether I think I will need it or not.

Dave, what wire is this 4/18 and 7/18? Thanks!

Thanks! May I ask what is the thinking behind 4 or 7 wires?

Dave, but having cat5/cat6 into that remote area, you just put an NI-700 or NI-900 there and connect it to the master through ethernet and use its RS2323/IR/IO ports. It's probably more expensive though I think a better solution and more flexible solution. Possible that you will need a switch/hub there, it is added cost... Hmm, probably you are right by just pulling an extra cable.