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firebat
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Long Serial Cables?

Sat Mar 03, 2007 7:31 am

Normally, serial cables are limited to 50FT unless you are using cable with a capacitance of 15pF/FT (can get to approx 166 FT). With that said, how many folks are attaching serial cables to their RBs installed on towers that are not easily accessible? Is there any issues with leaving a cable attached to the serial port of an RB532 and leave it unconnected at the other end. It could act like an antenna. Any comments?
 
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nickb
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Mon Apr 09, 2007 8:09 pm

I've wondered about using a CAT5 adapter and running the serial port over some cable to the tower base... but I haven't tried it. I'd be interested to hear the results!
 
changeip
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Mon Apr 09, 2007 8:56 pm

Usually you convert rs232 to rs422 to go over 50ft. You can buy small adapters that convert the voltage so you can use regular cat3 or 5

Sam
 
Dave_W
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Tue Apr 10, 2007 2:42 pm

Hi all, have a look at the moxa 311 http://www.moxa.com/product/nport_de-311.htm

it uses a little app that redirects your serial port of choice to the IP of the moxa unit.

Ive used theses for a while now with audio control gear, never had a problem. With one of these up a tower connected to the routerboard (or perhaps a number of routerbaords via a serial port switch http://www.bb-elec.com/product_family.asp?FamilyId=102 ) you could simply have a cat5 dropped to the base of the tower..

Just a thougt

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csickles
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Tue Apr 10, 2007 6:41 pm

So..
How about this for a sick little project...
A combination "RS converter / POE" injecter unit.

A small box at the base of a tower that provides power to the AP, Converts 232 to 432 and feeds the 100T up the tower over 2 lines or a combination of Copper for RS ans fiber for ethernet. Then a small box at the AP that splitts out the RS and ethernet / power or POE to the routerboard...

This would give you power to the tower,serial at the base, and possably with the aid of some of the serial over IP solutions, a remote serial terminal...

Not complicated electronics... and not expensive...

Things that make you go Hmmmmm...

If there is enough interest, I could build some...

Craig..
Things that make you go "Hmmmmmmmm"...

Craig
 
changeip
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Tue Apr 10, 2007 11:16 pm

rs422 takes 4 wires I believe ... 2 positive and 2 negative. Then POE is another 4 wires I believe ... you could run POE and 422 down the same cat5 but then would need another for data.

Sam
 
csickles
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Tue Apr 10, 2007 11:26 pm

Yeh...
That is what I was thinking of...

Or... There are some 100T cables with fiber in them as a component.

They use them on some high end swicthes.. they have a modified RJ45 connector that terminates both the light and copper.

The two line idea would be MUCH cheaper..

But I think it would make for a much cleaner installation and easyer to deal with.. IE fewer tower climbs...

You could also use them for office / multi tennant installations.
It would make installes cleaner and maint. easyer less need for ladders etc.

Craig
Things that make you go "Hmmmmmmmm"...

Craig

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