SpectraLink Corporation
Installation and Operation
Link WTS – Link 150 M3 MCU
When wiring the 8-pin connector, use the following table as a guide.
8-pin modular
connector
MCU Pin
Function
Polarity
1 Data
1 Any
2 Data
2 Any
3 Power
3
+
4 Power
2
-
5 Power
2
+
6 Power
3
-
7 Power
1
-
8 Power
1
+
4.4 Prepare Demarc Blocks
The MCU connects to the existing telephone system using RJ-21 connections. An MCU
is designed to operate with a specific interface to the telephone system: two wire digital
or analog, or four wire digital. The number of demarcation blocks required for the system
depends on the number and type of MCUs installed.
Interface Type
MCU
Part Number
Wire
Pairs
# Blocks
Analog POTS
SCA-5XX
1
1
Universal Digital Interface
(Norstar, Meridian, Comdial,
Fujitsu, Inter-Tel, DEFINITY 2-
wire, NEC, Rolm, Toshiba)
SCU-5XX 1 1
Merlin Legend and
DEFINITY 4-wire
SCF-5XX 2 2
Mitel (DNIC)
SCX-5XX
1
1
Panasonic (Universal 2-wire
Auxiliary Digital)
SCP-5XX 1 1
Executone (Universal 4-wire
Auxiliary Digital)
SCB-5XX 2 2
If the wiring between the Link 150 MCU and the telephone system leaves the
building, consult your telephone system manual for instructions on providing
adequate lightning and other over-current protection. All MCUs (except the
analog interface SCA-5XX) are intended only for connection to the isolated
side of an on-premises telephone switch. The interfaces are intended to
connect to digital telephone switch ports that provide signals of 5Vp-p (max)
AC component and some telephone switches provide a 48 V DC offset.
Based on the number and type of interfaces in the system, determine the number of 25-
pair cables required to connect line ports and Base Stations to the demarcation blocks.
Part Number: 72007501D.doc
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