Remote Diagnostic & Predictive Maintenance System (RDPMS) is an IOT based maintenance system that enables the monitoring, analysis and advance maintenance of various types of signaling devices remotely. It collects real-time data from various signaling gears to monitor parameters like temperature, voltage, current, vibration etc. which is transmitted to edge computing via station gateways for real-time data analysis by using AI & Machine Learning algorithms. The analyzed data is then transferred to a Central Cloud hub where the historical trends and real time data patterns are preserved to generate alert insights. This predictive maintenance feature of the system sends early warning signs, alerts or faults to web server and mobile applications. On the basis of those alerts the maintenance activities and preventive measures can be taken ahead of time.