Legend Extension pinouts

[MWM]

Guys:

... inherited a Legend v4 which, first of all, needs massive retermination. My legend manuals don't show the extension pinouts and I have gotten conflicting info about the pairs required for different extension types.

They have 408-MLX, 408-Voice Terminals, 408-ATL, 0x12 Ring Gen w/ 12 Basic Telephone and 0x16 Basic Telephone cards.

They have lots of Lucent 2500 sets w/ Message Waiting and even membrane Merlin sets (4-pair required here, I know.)

In Legend-land, are the Basic Telephone sets and the ATL sets both analog-only, single-pair wiring? Is this just a nomeclature difference? Classic Merlin sets are "Voice Terminals", right?

Someone said that MLX sets require 3-pair-- hybrid plus the 3rd pair for power. Or does it depend upon the type or size of MLX?

My guess: MLX sets get two pair, classic Merlin sets are "Voice Terminals" and get four pair; and ATLs & Basic Telephone sets get one pair. Right?

BTW, Unicom has octopus cables in 2-, 3- or 4-pair configs on 25-pr. amphenol connectors. Very convenient.

Thanks,
MWM

 

[TouchToneTommy]

Well, ATL sets are the classic Merlin "Voice Terminals". If you are not going to need Off-Hook Voice Announce, you can get by with 3 pairs, the Blue, Orange, and Green pairs of a 568-B configuration. OHVA takes up the Brown pair (and another station port)

MLX sets need the Blue and Green pairs, add Brown for the Operator's DSS/BLF.

Basic sets are Tip/Ring 2500-compatable sets, of course only require the Blue pair.

The insanity behind it all is to run a 4-pair cable and terminate it 568-B for EVERY station. Use a 4-pair jumper to go from the control unit to the block, and you're covered for every situation, no matter what set type is there today or tomorrow.

 

[ttech]

MLX set also need the brown pair if an MFM is used, But you don't see many around.

 

[tdaugirdas]

I use standard ethernet cable (4-pair) for all types of sets - and it works just fine. I believe standard ethernet cable uses 568A vs 568B color-coding. But, as long as you are consistent at both ends - either color-scheme should work.

Tom Daugirdas,
President
STCG, Inc.
stcg.com

 

[jlshelton]

Above information looks correct.
I've always used 4-pair (CAT-5 or better) wiring, on the theory that it will support any known phone, and Ethernet as well. Of course, that also makes it possible for people to plug things into the wrong jack and cause a problem (ringing voltage might fry an Ethernet board.) Color coded jacks can help.

It's a shame that the ATL sets, which support two independent voice paths, aren't well supported on Legend. To get the second voice path, as mentioned, you need a second ATL station port. Other systems (Merlin Plus, System-25) didn't require that.

Perhaps I am not understanding your question, but "membrane-type" phones generally ARE the ATL or "hybrid" phones that use all 4 pairs. They are "analog" in the sense that the two voice paths are analog, but there is a digital control signal to handle button-presses and lights.

The MLX phones are ISDN digital.

And yes, AT&T started calling them "Voice Terminals" in the early 1980s, perhaps in an attempt to sound up-to-date. Even a 2500 (basic desk telephone) was called a voice terminal.

 

[MWM]

Thanks, guys; this is all a great help.

For all the Basic sets, I understand I can use single-pair connections. ... Perhaps using an octopus modular cable (

http://www.unicomlink.com/products/voice_connectivity/telco_cables_adapters.asp)

with 16 one-pair legs, punched down via amphenol extension cables onto new 110 blocks, which then jumper to the existing horizontal distribution cables.

For the MLX, ATL and Voice Terminal jacks I understand it would be best to connect all four pairs to all stations. ... Perhaps the same octopus-type cables (Unicom) with six 4-pair legs.

With only two kinds of modular Legend plugs to provide, single-air and 4-pair, it is much simpler.

Thanks again.
Yours,
MWM