The LDMS, also known as the Local Data Monitoring System, performs the same task of acquiring data and tele-control from RTUs via Ethernet using the IEC 60870-5-104 protocol. The EHV/MV/LV substations have PC/printer setups with suitable SCADA software to view and print daily/hourly log sheets. The LDMS is a mini SCADA system that can be used in the substation control room building. It stores real-time telemetered and calculated data every five minutes, along with alarms, events, and SOE. Reports can be generated to analyze the maximum, minimum, and average values of all substation parameters. The LDMS also allows for manual data entry.

The LDMS will be a compact SCADA system with a user-friendly interface for use in substation control room buildings. The LDMS software includes various functions such as data acquisition for different types of data, data processing for conversion to engineering units and validity checks, as well as calculated data for values like maximum, minimum, and average with associated timestamps. It also has features like time synchronization, sequence of events processing, supervisory control, alarm management, tagging, trending, and quality codes. Additionally, it incorporates single-line diagrams, trends, and reports on a daily, weekly, and monthly basis. The LDMS is also capable of generating additional displays, single-line diagrams, reports, and trends as needed.

The LDMS updates analog data from RTUs every ten seconds, and status data is updated only when there is an exception. The SOE status data is recorded with a resolution of 10 minutes timestamp.