PXML No. BABT/PXML/23 PBX. 0013/0023/0025/0037

The SOPHO S10, S15, S25, S35 family is a range of fully digital business communication telephone systems that were designed and manufactured first by Philips and then by Telecom Sciences (Tsc).  Tsc were later bought by Mitel Telecom.

The  systems utilise proprietary "S0" extension interfaces which provide full "2B+D" signalling.  This enables the transmission of both speech and data using only the telephone system wiring.  Standard system capacities (subject to variations) are given below:-

SOPHO S10 6 10
SOPHO S15 6 28
SOPHO S25 8 44
SOPHO S35 14 72

By using option cards the range can be extended to the following systems capacity:-

SOPHO S10 6 10 4 20
SOPHO S15 12 28 4 44
SOPHO S25 26 44 12 82
SOPHO S35 26 72 12 110

The terminal range consists of the following six terminals:-

d163.jpg (74664 bytes)The SOPHO SET D163 (Tsc IMAGE 100) includes four fixed function keys, RECALL, TRANSMIT, HOLD AND PROGRAM.  It is also equipped with a red message waiting LED which flashes to alert the user when a message has been left at the terminal.  An integral loudspeaker enables the user to receive broadcast/paging messages from other extensions.

d263.jpg (69048 bytes)The SOPHO SET D263 (Tsc Image 200) has all the  functions and features available on the SOPHO SET 161, plus eight user programmable function keys (soft keys) that allow users to customise their terminals to their specific needs.  Each soft key can hold two functions, giving the Business Plus Terminal sixteen additional options - each programmable function key providing one "Primary" feature plus one "Secondary" feature.   Each function key has an integrated LED (Light Emitting Diode) which provides visual indication of the status of a line, and extension or a feature.

d266.jpg (85914 bytes)The SOPHO SET D266 (Tsc Image 300) has twelve programmable keys with dual LED's, full hands-free speech and a headset interface.

The Imagination Millennium 171 offers the features found on the D 163 plus a loudspeaker key, a programmable feature key (F1), and a mute key.  The Millennium range of terminals were the most recently designed and manufactured and many users prefer the robust and modern design.

d271.JPG (71433 bytes)The Imagination Millennium 271 offers the features found on the D 171 plus fully  hands-free speech, a large two line liquid crystal display (LCD), a volume control, plus an extra  programmable feature key.  Like the D171, the set is desk or wall mountable.

d366.jpg (77607 bytes)The Sopho Set D366 (Tsc Image 400).  This set  has all the features of the D-266 plus an  LCD that is used by the installer and System Supervisor, in association with a further three keys below the LCD, to amend system settings and parameters.


24 Key DSS Module attac
hes to either the D266 or D366 terminal to provide 24 extra programmable keys.  These are primarily used by the telephone operator as each key can be set for an extension, which not only gives the operator direct access but also a means to monitor which extensions are in use.

48 Key DSS Module Same as above but with 48 programmable keys.

Music on hold (external) provides a five pin DIN socket for connection of an external music on hold device, such as a CD player or MP3 machine.

2-wire interface (AAO) Card.  This card allows connection of two standard 2-wire devices such as a cordless telephone, fax machine, modem or answering machine.

6T Trunk Card allows connection of six exchange lines.

Tie Line Cards of various types are available such as E&M, DC5 and AC15.

Sopho S Socket Wiring

LJU 2/3C Wire colour MDF termination
2 Blue/White RX-
3 Orange/White TX-
4 White/Orange TX+
5 White/Blue RX+

Technical Information

To take advantage of ISDN lines the system requires ISDN trunk cards as well as "S0 to Desk" Option cards (often called IDS cards). These can be difficult to obtain and another way to to install ISDN in an older system is purchase a Mitel Imagination system as these will accept the terminals used on the Sopho S10, S15, S25, S35.

Each So bus must be terminated by a terminated line-jack unit. The second terminal is connected via a non-terminated line-jack unit.

Many terminals sold with Sopho S systems were fitted with plugs that look like standard BT plugs but the clips are reversed. Sockets that use these plugs were supply by Philips. Termination points are marked RX-, RX+, TX-, TX+. This corresponds to the MDF reference so you simply wire RX+ to RX + etc.

New terminals are fitted with standard RJ type plugs and can be fitted to ISDN sockets (terminated) or data sockets (non-terminated). These should be wired to the MDF, Pin 3 to R+, Pin 6 to R-, Pin 4 to T+, Pin 5 to T-.

When wiring co-located terminals (terminated to non-terminated) they should be wired like for like. For example RX+ to RX+ or pin 6 to pin 6.

Channel Selection
Because two terminals can occupy the same port, it is important to select the correct channel. The D163, D263, D266 and D366 have a switch on the bottom of the set to make the selection. The D171 and D271 terminals do not have a switch as they are set by software. To select simply hold down the HOLD and * key when the set is plugged in and when the monitor lamp flashes push 1 for channel 1 or 2 for channel 2. When the monitor LED stops flashing the terminal is set.

Distance Limitations
A terminal can be up to up to 200M from the Control Unit. If a longer line is needed, it is possible to connect a standard 2-wire telephone to an AAO card that is up to 1500M from the Control Unit.

Programming is far better accomplished with a PC or more often by using a D366 terminal. Sopho-S systems are very flexible and allow almost any configuration. At initial set-up the system is configured as a PABX, keysystem, or ACD system. Access to programming is password protected to avoid misuse.

It is important to receive training before attempting to programme.

Cordless Telephones
BT/Siemens Diverse DECT sets work very well via an AAO.


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Last revised: January 28, 2023