Physical Description

The optical link consists of five elements;

1. The Optical Link Source (OLS ): This card mounts as a mezzanine daughter-card on the sub-detector's ROC . It is connected with a 96-pin straight Eurocard connector (male on ROC , female on OLS ). This card was custom designed at CERN. A diagram of the OLS is shown in Figure .

2. Source OLC -266 card: This is a commercial fibre-channel card, supplied by IBM or HP. It is mounted as a mezzanine daughter-card on the OLS via a 48-pin connector. This card contains the laser diode which drives the optical fibre.

3. Optical fibre: The OLC -266 card connects via a "plastic" duplex SC-type connector to a 10m dual-fibre opto-cord. The other end of the opto-cord is terminated in two "diamond" (HFS-3) connectors which plug into an optical patch panel near the sub-detector. The panel mounted diamond connectors are spliced into a multi-fibre cable which runs from the experimental hall to the control room where it terminates in another patch panel. A second opto-cord then connects this to the second OLC -266 card. The optical fibre used has a core diameter of 50/125 m.

4. Destination OLC -266 card: This card is identical to the Source OLC -266 card. Each card has both a laser driver and a photo-diode receiver and is capable of duplex operation. It is mounted as a mezzanine daughter-card on the OLD . Note that the OLC -266 cards are delivered with the OLS and OLD and are to be considered an integral part of them.

5. Optical Link Destination (OLD ): This card is mounted as a front-panel extender card on the IB . It is connected with a 96-pin right-angled Eurocard connector (male on the OLD , female on the IB ). A diagram of the OLD is shown in Figure

  
Figure: General Arrangement of the Optical Link Source showing the OLC -266 mounted.

  
Figure: General Arrangement of the Optical Link Destination with the OLC -266 shown mounted.