UA-.NETStandard/samples/Reference/ConsoleReferenceClient

OPC Foundation UA .NET Standard Reference Client

Introduction

The console reference client can be configured using several console parameters. Some of these parameters are explained in more detail below.

To see all available parameters call console reference client with the parameter -h.

Supported transport profiles

The client picks the wire transport automatically from the serverUrl scheme. The OPC UA spec aliases the URL scheme to the TransportProfileUri on the negotiated endpoint:

URL scheme	TransportProfileUri	OPC UA Part 6 reference
opc.tcp://	uatcp-uasc-uabinary	§7.4.2
opc.https:// (or https://) with binary body	https-uabinary	§7.4.4
opc.https:// (or https://) with application/opcua+uajson body	https-uajson	§7.4.5
opc.wss:// (or wss://) with opcua+uacp sub-protocol	wss-uasc-uabinary	§7.5.2
opc.wss:// (or wss://) with opcua+uajson sub-protocol	wss-uajson	§7.5.2

Examples:

# UA-TCP (default)
dotnet ConsoleReferenceClient.dll opc.tcp://localhost:62541/Quickstarts/ReferenceServer

# WSS+uacp (binary UA SecureChannel over TLS WebSocket)
dotnet ConsoleReferenceClient.dll opc.wss://localhost:62543/Quickstarts/ReferenceServer

# HTTPS (binary)
dotnet ConsoleReferenceClient.dll opc.https://localhost:62543/Quickstarts/ReferenceServer

The reference server (ConsoleReferenceServer) advertises the opc.tcp://, opc.https:// and opc.wss:// endpoints by default; see docs/Transports.md for the full server configuration story (TLS certificates, mutual TLS, JSON sub-protocol restrictions, etc.).

Historical Access

Use --historian against the reference server to run the Part 11 sample workflow:

dotnet ConsoleReferenceClient.dll --historian --autoaccept --nosecurity \
  opc.tcp://localhost:62541/Quickstarts/ReferenceServer

The workflow uses ISession.Historian() to discover server and per-node configuration, follow paged raw and modified reads, read at-time and representative aggregate families, perform point and range deletes, and round-trip annotation Insert/Replace/Update/Remove batches. It also exercises generic KeyValuePair StructuredHistoryData through raw, modified, at-time, Insert, Replace, Update, and Remove operations, plus historical event insert/replace/update/delete. The workflow triggers and verifies automatic server-event capture, demonstrates server-generated EventIds, and releases continuation points automatically when an await foreach loop completes or exits early.

Reverse Connect

The OPC UA reverse connect feature allows an OPC UA server to initiate the connection to a client, rather than the traditional model where clients connect to servers. This is particularly useful in scenarios where the server is behind a firewall or NAT, making it difficult for clients to directly connect to it.

How to use Reverse Connect

To enable reverse connect mode, specify the client endpoint URL using the --rc or --reverseconnect parameter:

dotnet ConsoleReferenceClient.dll --rc=opc.tcp://localhost:65300 opc.tcp://localhost:62541/Quickstarts/ReferenceServer

The client will start a reverse connect listener on the specified endpoint (e.g., opc.tcp://localhost:65300) and wait for the server to connect to it.

Example: Client and Server with Reverse Connect

1. Start the client with reverse connect listener on port 65300:

   dotnet ConsoleReferenceClient.dll --rc=opc.tcp://localhost:65300 opc.tcp://localhost:62541/Quickstarts/ReferenceServer
   

2. In a separate terminal, start the server with reverse connect to the client:

   dotnet ConsoleReferenceServer.dll --rc=opc.tcp://localhost:65300 -a
   

The server will establish a reverse connection to the client endpoint, and the client will use this connection to communicate with the server.

How to specify User Identity

Username & Password

Specify as console parameters: -un YourUsername -up YourPassword

Certificate

Place your user certificate in the TrustedUserCertificatesStore (the path can be found in the client configuration XML). Make sure to include an accessible private key with the certificate. Specify console parameters: -uc Thumbprint (of the user certificate to select) -ucp Password (of the user certificates private key (optional))