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To capture the data required for preventative maintenance of track circuits, you will require a data logger with high frequency, optically isolated analogue inputs. The MPEC SA380TX or SA380TX-L data loggers are specifically designed to meet this requirement. Wiring guides is outside the scope of this document.
Since track circuits spend the majority of their time in an unchanged state, data should be sent to the server only when significant changes to the track circuit current occurs. This , this is referred to as acquire on change ("AoC").