CCD Bus

The CCD BUS is a twisted pair of wires traveling from module to module, receiving and delivering coded information. The code identifies the message and its importance. When multiple messages attempt to access CCD BUS at once, code assigns priority ranking. The 2 twisted wires used by the CCD BUS system are called BUS "+" and BUS "-". Both wires carry approximately 2.5 volts. The network consists of some modules with "bias" and some with "termination".

Bias is the part of the voltage divider network which places both BUS "+" and BUS "-" at 2.5 volts. Termination is the part of the circuitry required to complete the voltage divider network and also provide some electromagnetic protection for the CCD BUS. Terminations in all CCD applications have approximately 120 ohms resistance.