Sockets- Each So bus must be terminated to 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 supplied by Philips. Termination points are marked RX-, RX+, TX-, TX+. This corresponds to the MDF (main distribution frame-inside the control box) 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) you should wire like for like. For example RX+ to RX+ or pin 6 to pin 6. We normally stock all line-jack units (sockets) mentioned and can supply terminals with either RJ plugs or the BT (reversed clip). 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 base of the set to make the selection. The D171 and D271 terminals don't have a switch as they are set by software. You simply hold down the HOLD and * key when you plug the set in. When the monitor lamp flashes you 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.
ISDN - To take advantage of ISDN lines the system requires ISDN trunk cards as well as "SO to Desk" Option cards (often called IDS cards). These cards are very difficult to obtain, and we seldom have them in stock. ISDN was not a strong point on Sopho-S systems so our advice is that you should not purchase Sopho-S if you are planning to equip it with ISDN trunks.
| 
