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A connector manufacturer needed to extend a communication signal over a long distance in an installation where there could be removable equipment and several connectors in the path. The transmitted and received signals were TTL based and the long connection was to be an optical fibre. In the short term, they needed some prototypes to be designed and made to prove the concept. The circuit has the data path and a second test output to indicate whether the loss in the optical path is beyond a set limit. The data path has to work within a stringent delay requirement over a 16dB signal path variation and over a wide temperature range.The picture below shows the prototype with optical transmitter and receiver connectors (under protective covers) and a separate connector for power and data signals.
The prototypes were successfully tested and a surface mount board has been designed to fit within a standard military-style connector. The picture below shows a CAD generated, exploded view of the connector with the optical connections on the left and the TTL connections on the right.
We have now designed and delivered a tester for production verification of the connectors. The tester is shown in the picture below. It checks for the presence of the signals and also that the delays through the connector electronics from TTL to opto signals and back to TTL levels are within the timing specification.
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