Legend MLX wiring 1

[jayg9999]

I have not been able to find the wiring plan for the MLX phones in any of the PDF manuals I have downloaded (maybe I missed something!). In searching this forum, I came across a post saying that you only need 2 pairs for the phones if not using a DSS or the MLM cards (I am not using either). That being the case, can I just use std 4 wire RJ11 cables? Is there anything special I need of thr 20L?

 

[SYQUEST]

Hi jayg9999,
If you are not using any MFM or adjuncts on the MLX phones, you can use 2-pair wiring with 6P4C jacks. The third and fourth pairs are used to support those items. Remember "RJ11" is a wiring arrangement for Tip/Ring analoge dial tone lines on specific jack hardware. (The term has been sooo abused!)

The manuals are not very clear in this respect, I have been searching to find an "official" description or definition, but none to date. Now if you are using the MLX20L for a console it is best to use 4-pair cabling in the event a DSS is added later or other changes.

Hope this helps!
....JIM....

 

[jayg9999]

Say jalapeno, praise the ford.

thankx! That will simplify things for me alot. I hope I am not getting in over my head in programming the system. This forum is a great help

 

[jlshelton]

The AT&T Merlin Legend Release 1 manual provides a table for finding this information.

Pair 1 (jack pins 5,4) - Transmit +/-
Pair 2 (jack pins 1,2) - not used
Pair 3 (jack pins 3,6) - Receive +/-
Pair 4 (jack pins 7,8) - -48 VDC

Note that the Analog Multiline (ATL) phones use a different pair for power (pair 3), which is why it's not good to plug an MLX phone into an ATL slot or vice-versa.

 

[SYQUEST]

Hi jlshelton,
Thanks for your response! This is the answer I have been searching for and verifies my guesses about the MLX phones. I did not think to look in one of the earlier manuals. I will hunt for a copy to see what else it has. This is also a help when troubleshooting. Per my previous post, I stand corrected in that the third pair on pins 1&2 does nothing on MLX phones. AT&T had a habit of dropping info like that to make things non-technical in later versions.

.....JIM.....

 

[chcoale]

The white brown pair is a power pair. These are BRI based phones and will work off phantom power. The result is that anything that needs the second channel of the phone will not work, such as the MFM, DSS, the feature voice announce to busy, etc. Basically you are making a 2 channel phone into a 1 channel phone by not wiring the white brown pair. The white orange pair is not used.

Charlie Coale
301-352-3601

 

[bigheas537]

Thought I'd throw my 2 cents in. I have a Merlin Legend and have wired my entire system using the 586b scheme. Works like a champ.