Abstract: A remote logger unit monitors various operating parameters of a distribution line, or transmission system, such as pressure, temperature and flow such as for natural gas, water or oil, and alerts a central controller via an RF link when predetermined operating limits as determined by the logger unit are exceeded. A plurality of such remote logger units may be employed along the length of the distribution line for monitoring the complete system, with the reports of more distant logger units routed to the central controller via closer logger units. Each logger unit is passive in operation, autonomous and entirely independent of the central controller, and also provides routine operation data to the central controller when prompted, or at designated time intervals. The reported data includes the identity of the logger unit, the nature of the data or alert, and the time and date of the report.