How to Connect a Camera TTL Control Line?

This topic describes the recommended way to interconnect a control line between the camera and Domino Alpha 2. The signal direction can be UpStream (Grabber to Camera) or DownStream (Camera to Grabber). The electrical levels are TTL.

The present recommendation yields the best signal integrity as well as the best electromagnetic compatibility performance.

Refer to the following simplified electrical drawing.

This drawing shows that the TTL control signal is adequately transported by means of a twisted pair of wires. One wire transports the TTL signal, the other one is a ground connection.

The ground connection should imperatively be established at both connectors (camera side and board side).

Using a shielded or coaxial cable instead of the twisted pair is allowed, and even should be preferred when feasible.

The video cables and other control lines linking the camera to the board are preferably grouped into a single composite cable, equipped with an overall shield.

The overall shield is electrically connected to the camera body through the conductive camera connector. On the board side, the overall shield is connected to the HD15M conductive shell.