IEC 60870-5-103 Protocol

NEW in SerialMon v3.0! Full support for IEC 60870-5-103, the companion standard for protection equipment communication.

IEC 60870-5-103 defines the informative interface between protection equipment and devices for logging/evaluation in substations. It enables communication between protection relays and substation automation systems.

Protocol Overview

IEC 60870-5-103 is specifically designed for protection equipment:

  • Protection relay status and configuration
  • Disturbance recording data transfer (COMTRADE)
  • Protection settings readout and modification
  • Measurement values from protection relays
  • Event and alarm data from protection equipment

Protocol Structure

ISO/OSI Layer IEC 103 Layer
7. Application layer ASDU (Protection-specific types)
6. Presentation layer Application layer
5. Session layer
4. Transport layer Link layer (FT1.2 frame format)
3. Network layer
2. Data link layer
1. Physical layer Physical layer (RS-232/RS-485)

ASDU Types

Type ID Name Description
1 Time-tagged message Status with time tag (24-bit)
2 Time-tagged message with relative time Status with relative time
5 Identification Device identification data
6 Time synchronization Time sync command/response
7 General interrogation Station interrogation
8 General interrogation termination End of interrogation
9 Measurands I Measurement set 1
10 Generic data Flexible data format
20 General command Command to protection device
21 Generic command Flexible command format
23 Disturbance data ready Notification of available fault data
26-31 Disturbance data transfer COMTRADE fault recording data

SerialMon Support

Full support added in SerialMon v3.0

Operating Modes

Mode Description
Monitor Passive sniffing of IEC 103 communication between protection relays and control systems
Master Simulate a substation automation system polling protection relays
Slave/IED Simulate a protection relay responding to master requests

Supported Features

  • All standard ASDU types for protection equipment
  • General interrogation and time synchronization
  • Measurement values and status indications
  • Command execution
  • Disturbance data notification
  • Protocol validation and error detection
  • Signal acceptance marking for FAT/SAT testing
  • Quick command sending from tracking window

Use Cases

  • Protection Commissioning - Verify protection relay communication during installation
  • Troubleshooting - Debug communication issues between protection equipment and SCADA
  • FAT/SAT Testing - Factory and site acceptance testing with signal verification
  • Integration Testing - Test protection relay integration before go-live
  • Disturbance Analysis - Monitor and capture fault recording notifications

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