| 摘要 |
<p>The circuit consists of groups of identical, interchangeable units, each including a converter and a multiplexer for the analogue-to-digital direction, and interlinked so that the analogue side of each converter can be connected to the de-multiplexed side of each multiplexer in the group. Only one converter is used to handle all lines served by the group, as determined by a selection circuit. In case of failure, another converter from a different unit in the group can be selected. Similarly for the digital-to-analogue direction, the units also have a decoder and a demultiplexer, and are interlinked so that the multiplexed side of each de-multiplexer can be connected to the analogue side of each decoder, by appropriate command to a second selection circuit. Servicing and maintenance only require replacing faulty units in the form of PCB.</p> |
