Background
Track circuits are a safety & operationally critical part of the railway but inherently suffer from a variety of common preventative failures. Due to their exposed nature, both to the elements and contact with a variety of rolling stock, the operational nature if track circuits can change over time and per each individual rolling stock "event".
Data logging requirements
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.
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 is referred to as acquire on change ("AoC").