Schneider Easergy P5 Communication Protocol Complete Guide

Schneider Easergy P5 Communication Protocol Complete Guide

In modern power automation systems, protective relays are not only the executors of fault detection and isolation, but also the core nodes for data exchange in smart grids. Schneider Electric's Easergy P5 series protective relays, with their powerful communication capabilities, have become a key bridge connecting substation automation systems (SAS), monitoring and data acquisition systems (SCADA), and intelligent electronic devices (IEDs).

This article aims to comprehensively analyze the communication architecture and protocol implementation of Easergy P5 protection relay. From basic serial communication to high-performance Ethernet redundant networks, from international standard IEC 61850 to widely used Modbus and DNP3, this article will elaborate on the communication capabilities, configuration methods, and technical details of the P5 series products, providing a professional technical reference guide for power system engineers and technicians.

1. Overview of Communication Architecture

Easergy P5 protection relay supports multiple communication architectures and can be flexibly selected according to application requirements:

1.1 Serial Network Architecture

Serial communication adopts a multi drop structure and follows the master-slave communication principle. Multiple Easergy P5 relays can be connected to HMI or SCADA systems via RS-485 serial links for point-to-point communication. This architecture is suitable for small substations or industrial sites that do not require high communication speed but require simplified wiring.

1.2 Ethernet Network Architecture

The Ethernet architecture directly connects multiple Easergy P5 relays to the Ethernet network, supporting faster data exchange and more complex network topologies. Its core advantages lie in:

Multi protocol concurrency: Up to three protocols can be used simultaneously on the same Ethernet port, including IEC 61850, GOOSE, Modbus TCP, DNP3 over TCP, EtherNet/IP, etc.

High availability: Achieve a network fault recovery time of 0 milliseconds through Parallel Redundancy Protocol (PRP) and High Availability Seamless Redundancy (HSR).

Network Management: Supports SNMP (Simple Network Management Protocol) for network monitoring, SNTP (Simple Network Time Protocol) for time synchronization, and HTTPS (Secure Hypertext Transfer Protocol) for Web HMI access.

2. Communication ports and hardware options

2.1 Ethernet communication slot

Easergy P5 offers multiple Ethernet module options, which can be selected according to redundancy requirements:

Module Type Port Type Redundancy Management

Dual port copper cable (RJ45) 10/100BASE-T RSTP

Dual port fiber optic (multimode) 100BASE-FX RSTP

Dual port fiber optic (multimode) 100BASE-FX PRP/HSR (occupying two slots)

2.2 IP Address Configuration Strategy

Easergy P5 supports up to three IP addresses (IP1, IP2, IP3), and its configuration follows the following rules:

When using only one Ethernet module, IP1 and IP2 can be configured

When using two Ethernet modules, IP1 and IP3 are assigned to each module separately

When using PRP/HSR modules, only IP1 is used

The network number of each IP address must be different, for example, IP1=192.168.1.21, IP2=192.168.2.31

2.3 Serial Communication Slot

The serial communication module supports:

RS-485 (2-wire or 4-wire), RJ45 interface

Fiber optic serial communication module

2.4 Port Security Enhancement

For network security reasons, Easergy P5 allows specific communication ports to be disabled through the front-end panel or software tools. This' port hardening 'function can effectively reduce the attack surface and only open necessary communication channels. After the port or protocol status changes, the device needs to be restarted to take effect.

3. IEC 61850 Communication: Core Protocol for Intelligent Substations

IEC 61850 is the most important communication standard in the field of power automation, and Easergy P5 provides comprehensive support for IEC 61850 Edition 1 and Edition 2.

3.1 Protocol Capability

Server role: As an IEC 61850 server, it supports up to 8 simultaneous client connections

Data model: Fully implement the logical nodes (LN) defined in IEC 61850-7-4

Reporting mechanism: Supports Buffer Report Control Block (BRCB) and Non Buffer Report Control Block (URCB)

GOOSE Communication: GOOSE messages supporting publish/subscribe mode for fast communication between IEDs

Set group control: supports selecting activity setting groups through SGCB class

File transfer: Supports extracting disturbance record files in COMTRADE format through file transfer

3.2 Configuration toolchain

IEC 61850 configuration uses two types of software:

eSetup Easergy Pro：

Used to send IEC 61850 configuration to devices

Can automatically scan devices in the network

Support importing CID files

CET850 configuration tool:

Used for creating, editing, and optimizing IEC 61850 configurations

Support editing and generation of ICD, SCD, IID, and CID files

Provide a graphical SCL file editor

3.3 Configuration Process

The IEC 61850 configuration file types include:

ICD: Description of IED capabilities, defining the data model and communication services of the device

CID: Description of the configured IED, including specific device configurations

SCD: System Configuration Description, including the communication configuration of the entire system

Configuration process:

Create system configuration from ICD file using CET850

Edit Dataset, Report Control Block (RCB), GOOSE Control Block (GoCB)

Generate CID file

Download CID files to the device through eSetup Easergy Pro

3.4 GOOSE Communication Configuration

GOOSE (General Object Oriented Substation Event) is a key technology for achieving fast communication between IEDs.

Publisher configuration:

Create a dataset and select the data attributes to be published (DA)

Configure GoCB, including multicast MAC address, retransmission time (fastest 4ms), maximum retransmission interval (heartbeat cycle)

The dataset size needs to be compatible with Ethernet frames

Subscription configuration:

Select the data attributes in the GOOSE message to subscribe to

Assign subscribed data attributes to GOOSE network inputs (NI)

Supports 128 binary GOOSE inputs and 8 analog GOOSE inputs

GOOSE Matrix:

Through the GOOSE matrix, GOOSE network inputs can be mapped to virtual inputs (VI 1-20) to achieve integration with relay application logic. The same network input can be mapped to multiple virtual inputs, and multiple network inputs can also be mapped to the same virtual input (for "OR" logical operations).

3.5 Performance and Compliance with Standards

The GOOSE performance of Easergy P5 meets the P2 level (<10ms) requirements of IEC 61850-5 and IEC 61850-10.

4. DNP3 Protocol: Reliable Data Collection and Control

DNP3 (Distributed Network Protocol) is a widely used data acquisition and control protocol in the power industry. Easergy P5, as a slave device, supports serial port mode and TCP/IP mode, with a maximum of 8 client connections.

4.1 Functional Features

Status polling and reporting: Supports polling static status values through Class 0, and reporting data change events by category (Class 1, 2, 3)

Measurement value polling: supports static measurement value polling, configurable dead zone value management measurement value event reporting

Remote control: supports control commands such as selection, operation, and direct operation, and supports two control models: direct control (DC) and pre selection operation (SBO)

Counter management: supports polling of counter values

Time synchronization: Supports time synchronization command requests, which can be synchronized through absolute time objects or last recorded time objects

File transfer: Supports the extraction of disturbance record files (COMTRADE), and supports operations such as opening, closing, reading, and obtaining file information

4.2 Technical Parameters

Maximum data link frame size: 292 bytes (send)/292 bytes (receive)

Maximum application layer fragment size: 2048 bytes (send)/2048 bytes (receive)

Link layer retry count: configurable 0-255

SBO timeout: 60 seconds

4.3 Data Mapping

Easergy P5 maps data to five object categories of DNP3:

Binary Input (BI)

Dual input (DBI)

Analog Input (AI)

Counter (CNTRS)

Binary Output (BO)

Each type of data point can be configured with a category, whether to generate a non request response (UR), and a dead zone value (AI).

5. Modbus protocol: an industrial universal communication standard

Easergy P5 supports Modbus as both a slave and master, meeting the needs of different application scenarios.

5.1 Modbus Slave

Transmission mode:

Serial RTU mode: RS-485 physical layer

TCP/IP mode: Ethernet, supports up to 3 IP addresses and 8 clients

Supported functional codes:

03: Read and hold register

04: Read input register

06: Writing a single register

07: Read abnormal status

08: Diagnosis

16: Write multiple registers

23: Read/write multiple registers

43/14: Read device identification

Event management:

Standard Modbus: Read events from hold registers 2101-2105, up to 49 latest events

PDM Modbus: Maintain FIFO buffer for 100 events, provide table descriptors and event lists

List of data points:

Standard Point List (Enable 'Enable Traditional Points' setting)

PDM point list (default), supports data types such as Float32, ∝, Uint32, etc

5.2 Modbus Master Station

The Modbus master function allows Easergy P5 to act as the master and read the analog and digital inputs and outputs of external Modbus I/O devices through the RS-485 bus.

Configuration parameters:

Analog input: up to 64 points, configurable address, register type, unit, scaling ratio, alarm threshold

Digital input: up to 18 points, configurable address, register/coil type, selected bit

Digital output: up to 16 points, configurable address and coil type

Application:

External analog inputs can be displayed on the HMI and linked with protection functions to achieve more complex automation logic.

6. IEC 60870-5-101/103 protocol: Traditional power communication

6.1 IEC 60870-5-101

This protocol is defined in unbalanced mode, where Easergy P5 operates as a controlled station (slave) and supports the following application functions:

Process data transmission

Event transmission

Command transmission

Total query

clock synchronization

Total points transmission

Transmission delay acquisition

Data Model:

Single Point Information (SPI)

Double Point Information (DPI)

Analog Input (AI)

Simulated Event (AE)

Total points (IT)

Command (CMD)

Scaling mechanism:

The measured value can be configured as a scaled value, normalized value, or floating point value. Scaling formula: valueScaled=k × valueInternal

6.2 IEC 60870-5-103

This protocol is used to protect communication between devices and control systems. Easergy P5, as a secondary station (slave), supports the following ASDU types:

ASDU 1: Messages with time stamps

ASDU 3: Measurement value I

ASDU 4: Measurement values with relative time scales

ASDU 5: Identification Message

ASDU 6: Time synchronization

ASDU 8: Total query termination

ASDU 9: Measurement Value II

Set data read and write:

Support reading and writing setting parameters through ASDU 140, 143, 144, 201, with each setting item addressed through FUN and INF.

7. EtherNet/IP protocol: Industrial Ethernet standard

EtherNet/IP is an industrial Ethernet standard based on CIP (Common Industrial Protocol), with Easergy P5 working as an adapter.

7.1 Message Types

Unconnected Message (UCMM): A single request/response used to establish a connection

Explicit message (Class 3): point-to-point connection, used for cyclic querying of data, supports up to 6 simultaneous connections

I/O message (Class 1): point-to-point or multicast, used for cyclic I/O data exchange, supports only one connection

7.2 Object Model

The standard objects implemented by Easergy P5 include:

Identity Object (0x01): Device identifier

Message Router (0x02): Message Router

Assembly Object (0x04): Data Assembly

Connection Manager (0x06): Connection Management

TCP/IP Interface (0xF5): TCP/IP interface

Ethernet Link (0xF6): Ethernet Link

Application target:

Control Supervisor（0x29）

Overload（0x2C）

Digital（0x64）

Analog（0x65）

StgProtCurrent（0x66）

StgProtEF（0x67）

StgProtOther（0x68）

StgGeneral（0x69）

7.3 I/O Assembly Examples

Static assembly (Examples 2 and 50): User cannot modify content

Dynamic assembly (instances 100 and 150): Users can select data items, up to a maximum of 128 bytes

Any configuration changes require the generation of a new EDS (Electronic Data Sheet) file, which is generated through eSetup Easergy Pro and cannot be directly extracted from the device.

8. Network redundancy protocol

8.1 Parallel Redundancy Protocol (PRP)

PRP transmits frames in parallel on two independent networks (LAN A and LAN B), with the receiving device responsible for discarding redundant frames and providing 0 milliseconds of fault recovery time.

Key features:

Dual Attachment Nodes (DANPs) use the same MAC and IP addresses

The Link Redundancy Entity (LRE) is responsible for frame replication and deduplication

Support single attached node (SAN) connection through redundant box (RedBox)

8.2 High availability seamless redundancy (HSR)

HSR is used for ring network topology, where frames are transmitted bidirectionally along the ring, and the receiving device discards redundant frames, providing a 0 millisecond recovery time.

Key features:

Dual Attachment Nodes (DANH) Running in a Loop

LRE includes a switching matrix that supports direct switching

Add HSR labels to each frame for duplicate detection

8.3 Fast Spanning Tree Protocol (RSTP)

RSTP eliminates loops by transforming the mesh topology into a tree topology, and the recovery time depends on the network size and topology (<50ms/10 devices).

Configuration parameters:

Bridge Priority 

Hello Time（2s）

Forward Delay（15s）

Max Age（20s）

Port path cost and priority

9. Time synchronization

9.1 Precision Time Protocol (PTP)

PTP (IEEE 1588v2/IEC 61588) provides microsecond level accuracy and is only supported on PRP/HSR modules. It supports transparent clock (TC) and best master clock algorithm (BMCA).

9.2 Simple Network Time Protocol (SNTP)

SNTP is used for system clock synchronization and can be configured with a primary NTP server and a backup NTP server. The IP address can be configured in the CID file.

10. Network security features

10.1 Client IP Address Filtering

Easergy P5 supports IP address whitelist functionality based on CIDR (Classless Inter Domain Routing) notation:

Only allow connections from IP addresses in the list after activation

Up to 8 IP address ranges can be configured

The number of dynamic connections should not exceed 8

Effective immediately after modification, no need to restart

10.2 Secure Communication

SSH: Used for secure communication between eSetup Easergy Pro and devices (port 22)

HTTPS: Used for Web HMI access

SFTP: Used for secure file transfer

10.3 SCADA Access Control

The 'Via SCADA' parameter allows for the prohibition of setting changes and control commands through SCADA protocols (Modbus, IEC 61850, IEC 103), while retaining access to local HMI, USB, and eSetup Easergy Pro.