Abstract: A method and apparatus for storing interleaved synchronous and asynchronous data in a single data storage file is disclosed. Synchronous data and asynchronous data are stored in an interleaved order. Synchronous data is stored at regular periodic intervals and is stored within the data storage file in a data record having a constant sized data field. At least one data pattern is precluded from use as synchronous data. Data associated with asynchronous events are stored in the data storage file in a data record starting with this precluded data pattern, and followed by a field indicating the asynchronous event type. The time interval from an event associated with the previously recorded data can be determined and optionally stored in a variable length time-interval data field. The size of the variable length time-interval data field is stored in a time-length data field.

Abstract: A UART protocol which takes advantage of an SDO line space state to optimize communication between computers. A delay is provided by sending a byte of actual data followed by a dummy byte. The dummy byte is produced by placing the SDO line in the mark state, thus freeing up CPU time.

Abstract: A contact closure data logger which monitors state changes in a main switch, and records the time at which the state changes occur. To conserve power and accommodate less capable microprocessors, monitoring is done on a discreet basis. Various types of switches can be used, such as reed switches, FETs and mechanical switches, making the logger particularly useful for energy usage monitoring studies and retrofit of tipping bucket rain gauges. Dependent switches and measurement devices can be arranged in a hierarchical fashion to be monitored and otherwise acted upon when state changes occur in the main switch.