Samsung NX-308 User manual

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




SAMSUNG TELECOMS
Publication Information
Samsung Telecoms reserves the right without prior notice to revise
information in this publication for any reason.
Samsung Telecoms also reserves the right without prior notice to make
changes in design or components of equipment as engineering and
manufacturing may warrant.
Copyright 1998
Samsung Telecoms
All rights reserved. No part of this manual may be reproduced in any form or
by any means - graphic, electronic or mechanical, including recording,
taping, photocopy or information retrieval system - without express written
permission of the publisher of this material.
NOVEMBER/98

1
Contents
Introduction 3
General Description
System Overview 6
Specifications 9
Installation
Installation Requirements
Site planning 12
Electrical specifications 12
Installation Procedure
Mounting the KSU 14
Grounding the KSU 14
Connecting keysets 17
Connecting single line telephones 17
Internal music source 19
External music source connections 20
External system paging connections 20
Connecting door phone and lock control 20
Connecting PSTN lines 21
Power Failure Transfer 21
AC power connection 22
Connecting system back-up battery 22
Memory protection 22
Installing surge protection equipment 23
Before power on 23
Figures
Figure 1 KSU Layout 13
Figure 2 KSU Dimensions 15
Figure 3 KSU Connection Table 16
Figure 4 Base Board Switch Locations 18
System Programming
Levels of Programming 26
Station 26
User (Customer) 26
Technician 27
Programming Procedures 28
MMC Index 52

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Instroduction
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5
GENERAL
DESCRIPTION

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System Overview
System Operation
NX-308 system is a stored-program-controlled electronic key/hybrid telephone system ready to use as
soon as it is turned on. A powerful 8031 microprocessor operating at 11.059 MHz digitally controls all
speech paths and system functions. The operating program with default memory is stored in non-
volatile ROM, 27512. Customer data is stored in RAM, 62256, and protected by a Ni-Cd battery for up
to thirty days’continuous loss of system power. When AC power is restored, the Ni-Cd battery is
recharged.
There is a maximum capacity of three (3) telephone lines and eight (8) stations of which six (6) stations
can be easily selected as keysets and single line telephones.
Comprising only a key service unit (KSU), electronic keysets and conventional single line telephones,
NX-308 offers small business users flexibility and control of telephone communications.
System Configuration
NX-308 system comprises a KSU, proprietary electronic keysets, conventional single line telephones,
proprietary door phones, and conventional additional feature equipment. The plastic-cased KSU
provides all the powerful features itself, making for easy, convenient installation and maintenance.
The KSU is equipped to operate three (3) telephone lines and eight (8) stations. Stations from 1 to 2
are assigned for electronic keysets; stations from 3 to 8 are assigned to be used with either single line
telephones or keysets.
NX - 308 is a fully non-blocking system.
Circuit Type Location Number
Electronic Keyset Station 1 to 8
Single Line Telephone Station 3 to 8
C.O./PBX Line (loop start) Trunk 1 to 3
System Hardware
Key Service Unit (KSU)
The KSU is a single-cabinet, wall-mounted, plastic-cased unit measuring 420mm (H) x 300mm (W) x
84mm (D), and weighing 4.5 kg. It contains the following assemblies:
Power Supply - provides all the regulated DC voltages necessary for system operating from 220V
AC power. Also contains a charge/discharge circuit for 24V external battery back-up connections
and ring generator for conventional single line telephones.
Base Board - the main printed circuit board that contains CPU memory, common control, and
switching circuitry. Provides interfaces for telephone lines 1 through 3, stations 1 through 8, and
these additional features:
Music on hold & background music source
External paging
Power fail transfers for lines 1 through 2
One door phone with lock release contact
Also contains memory back-up battery and real-time clock.

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Stations 1-2 for keysets, and stations 3-8 for keysets or single line telephones, are switch-
selected.
Door Phone/Room Monitor
This is an optional wall-mounted unit containing a call button, microphone and speaker. It connects to
the KSU via two pair twisted wiring and does not take up a C.O. line or station position. Only one is
allowed per system.
The door phone provided by Samsung Electronics is commonly used for all Samsung key/hybrid
telephone systems. Other types cannot operate with these systems.
A door lock release unit may be connected to operate together with the door phone. To install the unit,
refer to the Installation section of this manual.
Telephones
Two types of telephone sets can be connected to the NX-308 system: proprietary electronic keysets and
conventional single line telephone sets.
The NX-308 24 Button Display keyset has the following standard features plus a large, easy to read,
one-line, 16-character liquid crystal display.
Standard Features
Full speakerphone capability.
Keyset comes as a desk model with reversible base wedge and handset clip for wall mounting at no
extra cost.
Handset and base cord connectors are designed with strain relief channels for longer cord life and
more static-free connections.
46 buttons configured as follows:
12 dial buttons (from 0 to )
3 C.O. line buttons with red and green LED indications
8 DSS/BLF (1-8) buttons that also function as eight personal speed dial buttons
8 speed dial buttons (9-16)
15 feature buttons:
Door Phone - DOOR
Call Pick-up - PICKUP
Group Listening - GRP.LISTEN
Internal Page - INT.PAGE
Attendant - ATTENDANT
Alarm/Speed dial - ALM/SD
Message - MSG
Conference - CONF
External Page - PAGE
Speaker - SPK
Last number redial - RD
Mute/Do Not Disturb - MUTE/DND
Hold - HOLD
Auto-Redial
Call-Back.
Two +/- push button volume selectors on front of keyset.

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Convenient pull-out tray under keyset for directory information.
All Samsung handsets are fully hearing aid compatible.
Conventional Telephones
Any industry-approved single line telephone using one pair (two wire) tip and ring circuitry may be
connected to a single line station port in the system. The ringer equivalency of any such phone must
not exceed 1 or damage to the system may result.

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Specifications
System Capacity
3 C.O./PBX Lines (Loop Start)
8 Stations:
- up to eight keysets
- up to six single line telephones
3 Internal Speech Paths
1 Audio Channel for System Tones
1 Audio Channel for Music (Internal Melody or External Source)
1 Door Phone with Lock Release Contact
Automatic Power Failure Transfer Circuits, 2 Telephone Lines
1 External Page
Power Specifications
AC Input: 220 VAC at 50/60 Hz
Voltage Range 180 - 260 VRMS
Power Consumption: 40 Watts maximum
Max Current Draw: 1.0 AMP
Ring Generator: 80 VRMS 20 Hz
Battery Back-up Supply: 24 VDC batteries rating not less than 6 AH but not more
than 40 AH
Environmental Limits
Operating Temperatures: 0o- 45oC (18o- 25oC recommended)
Operating Humidity: 10- 90% (without condensation)
Cable Requirements
Electronic Set: 2 pair twisted, 400m 24AWG maximum
Single Line Telephone: 1 pair twisted, 400m 24AWG maximum
Door Phone: 2 pair twisted, 100m 24AWG maximum
Physical Dimensions & Weights
Key Service Unit: 400 mm H x 300 mm W x 82 mm D, 4.5 kg
Keyset: 230 mm H x 195 mm W x 82 mm D, 1.0 kg
Door Phone: 130 mm H x 98 mm W x 28 mm D, 0.2 kg
External Music Source Input: Impedance 600 ohms, 350 mV
External Amplifier Output: Impedance 600 ohms, 1.24 VRMS

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Audible and Visual Indications
LED Indications
L E D
C.O. line red
(green/red)
Intercom LED
(red)
Progress Tones
Status
OFF
Flashing green every 0.5s
Flashing red every 0.5s
Flashing green every 0.1s
Steady red
Steady green
OFF
Flashing every 0.5s
Flashing every 0.1s
Steady ON
Line Status
Idle
On hold your station
On hold other station
Incoming call
In use other station
In use your station
Idle
Station is on hold
Station calling
Busy
Tone Status
Dial tone Continuous
Busy tone 0.5 sec On, 0.5 sec OFF
Ring back tone 1 sec ON, 2 sec OFF
Transfer tone 0.2 sec ON, 0.2 sec OFF
(conference tone/
confirmation)
Not used tone 0.5 sec ON, 2.5 sec OFF
- When the seized trunk line is not real
Confirm tone 2 sec ON, once
- When a call reservation is made
Burst tone 0.2 sec ON, 0.2 sec OFF, three times, keyset only (keyset ring)
- In Diagnostic, a button is pressed
Ringing Signals
C.O. line ring
Station ring
Door phone ring
Alarm ring
1 sec ON, 2 sec OFF
0.4 sec ON, 0.2 sec OFF, 0.4 sec ON, 2 sec OFF
0.2 sec ON, 0.2 sec OFF
0.5 sec ON, once, keyset only
- A station rings when busy

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INSTALLATION

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Installation Requirements
Site Planning
Select a KSU location that has enough space for easy installation, is well ventilated and has
adequate lighting.
Select a KSU location to minimise station cable lengths. Maximum cable length is 400 metres
using AWG 24 cable for telephones.
Equipment should not be exposed to direct sunlight, corrosive fumes, dust, constant vibration or
strong magnetic fields such as motors, copying machines, etc.
A direct commercial AC power outlet is required. Do not use an extension cord.
Ensure that all wires and cables going to and coming from the KSU are properly routed. Do not
cross fluorescent lights or run parallel with AC wires.
The equipment must be located within a temperature range of 0o- 45oC and a humidity range of
10% - 90% (without condensation).
Do not install equipment within a 2-mile radius of a broadcasting antenna.
Electrical Specifications
Input: Commercial AC POWER source: 220V AC
50/60 Hz Single Phase
Output for driving: 28 V max 0.4 A DC
22 V min 0.4 A DC
Current draw: Maximum 1 AMP
Power dissipation: Maximum 40 Watts
Fuse: Main power fuse 1 AMP, 250 V rating, slow acting
Battery fuse 3 AMP, 250 V rating, slow acting
WARNING
For continued protection against risk of fire, replace only
with same type and rating of fuse

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Figure 1 - KSU Layout

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Installation Procedure
Mounting the KSU
Select a wall that is strong enough to support the weight of the KSU (maximum 4.5 kg).
Select hardware that will support the system when it is mounted. It is recommended that the KSU
be mounted on a plywood backboard no less than 1.5 mm thick.
Secure the KSU with screws using mounting holes in flanges on right and left sides (Figure 2). Do
not over-tighten the screws or the slots on lefthand side of KSU could be squeezed closed.
Plug in the KSU.
Grounding the KSU
NX - 308 system requires a solid earth ground to the KSU frame (maximum 50 ohms).
Failure to provide an adequate ground may cause confusing trouble symptoms or even circuit board
failure.
In most cases, the third wire ground at the AC power outlet will be satisfactory. If you are not sure
of a good, solid ground on third prong of outlet, connect the grounding lug on KSU to a ground rod
or metal cold water pipe using 10 AWG solid copper wire.
NB: Do not use both methods of grounding. Use only one path to ground. The third wire of
the electrical cord may be disconnected from the power supply board then taped and stored, if
you connect ground through the other path.
WARNING
Hazardous voltages may cause death or injury. Observe extreme caution when
working with AC power line voltage.

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Figure 2 - KSU Dimensions (mm)

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Connection Table
The NX-308 system is equipped with a standard Amphenol connector, and its connections are shown in
the following table. All the necessary Station connections may be accomplished through this
connector.
The PSTN lines are connected to a customer-supplied LJU via the line cords supplied with the system.
Amphenol
Connector
Pin No.
Colour LJU
Pins
Connections
26 1
27 2 WH BL WH OR Reserved Reserved
28 3
29 4 WH GR WH BR Reserved Reserved
30 5
31 6 WH SL RD BL Ext. Music Source Ext. Page Tip, Ring Data - Data + (No polarity) (No polarity)
32 7
33 8 RD OR RD GR 4 3 5 2 Station 1 (Keyphone only) Tip, Ring Data - Data + (No polarity) (Polarity)
34 9
35 10 RD BR RD SL 4 3 5 2 Station 2 (Keyphone only) Tip, Ring Data - Data + (No polarity) (Polarity)
36 11
37 12 BK BL BK OR 4 3 5 2 Station 3 Tip, Ring [Data - Data +] (No polarity) (Polarity)
38 13
39 14 BK GR BK BR 4 3 5 2 Station 4 Tip, Ring [Data - Data +] (No polarity) (Polarity)
40 15
41 16 BK SL YL BL 4 3 5 2 Station 5 Tip, Ring [Data - Data +] (No polarity) (Polarity)
42 17
43 18 YL OR YL GR 4 3 5 2 Station 6 Tip, Ring [Data - Data +] (No polarity) (Polarity)
44 19
45 20 YL BR YL SL 4 3 5 2 Station 7 Tip, Ring [Data - Data +] (No polarity) (Polarity)
46 21
47 22 WH/BL BL WH/BL OR 4 3 5 2 Station 8 Tip, Ring [Data - Data +] (No polarity) (Polarity)
48 23
49 24 WH/BL GR WH/BL BR L1 L2 P- P+ Door phone Tip, Ring GND, Power (No polarity) (Polarity - Caution)
50 25 WH/BL SL Door lock L1, L2 (No polarity)
Note: Stations 3 to 8 can be configured as keysets or single line telephones (SLTs).
When connecting SLTs to the system the Data pairs are not required (shown in brackets in the table),
However the Tip and Ring pair need to be connected to LJU Pins 2 and 5.
Figure 3 - KSU Connection Table

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Connecting Keysets
Four wires (two pair) twisted cable with a double-sided modular plug and a terminal block are
recommended for a keyset connection to the KSU. One end of the terminal block is connected to the
MDF via a 50-pin cable, and the other end of the terminal block is connected to a keyset via a double-
sided modular plug line (two pair).
Cabling terminal block
LJU Pin 1 reserved
Pin 2 Data +
Pin 3 Voice (Ring)
Pin 4 Voice (Tip)
Pin 5 Data -
Pin 6 reserved
The voice pair has no polarity. However, take care when connecting the data pair because of
its polarity. Make sure that the cable run length does not exceed 400 metres using 24 AWG
wire.
All station cabling must be twisted pair.
Refer to the Amphenol connection table in Figure 3.
Connecting to hybrid station port
The system is equipped with six hybrid station ports which can accommodate keysets or single line
telephones. Each port should be selected for use as a keyset or single line telephone. Any of these
ports may be used for a keyset station and its connection method is the same as above.
Before cabling, the related DIP switches should be set as follows:
The selection of each hybrid station requires you to move four levers at one DIP switch.
3rd Station S1 DIP
4th Station S2 DIP
5th Station S3 DIP
6th Station S4 DIP
7th Station S5 DIP
8th Station S6 DIP
Each DIP switch comprises four levers which should be set to “K”positions for keyset
assignment. These are marked on the board.
Connecting Single Line Telephones
A single or two-pair twisted cable with a double-sided modular plug and a terminal block are
recommended for connecting a single line telephone to the KSU. One end of the terminal block is
connected to the MDF via a 50-pin cable and the other end is connected to the single line telephone via
the twisted modular cable.

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Figure 4 - Base Board Switch Locations
Cabling terminal block
LJU Pin 1 reserved
Pin 2 Tip or Ring
Pin 3