opcua

Create OPC UA client object

Syntax

uaClient = opcua(serverInfoObj)

uaClient = opcua(serverUrl)

uaClient = opcua(hostname,portnum)

uaClient = opcua(___,Name=Value)

Description

uaClient = opcua(serverInfoObj) creates an OPC UA client object associated with the server specified by serverInfoObj. You can create server info objects with the opcuaserverinfo function.

uaClient = opcua(serverUrl) creates a client object associated with the server referenced by the URL specified in serverUrl.

uaClient = opcua(hostname,portnum) creates an OPC UA client object associated with the server at port portnum on the host identified by hostname.

uaClient = opcua(___,Name=Value) specifies additional configuration options to create an OPC UA client object. (since R2025a)

By default, the client selects the most secure endpoint configuration from the list of all available connection configurations retrieved from the server. If the attempt to retrieve endpoints fails, an error is generated. You can override the default settings by using the name-value arguments.

Examples

Create OPC UA Client with Server Object

Create a client for the first server found on the local host.

s = opcuaserverinfo("localhost");
uaClient = opcua(s(1));

Create OPC UA Client with Discovery URL

Create a client using the discovery URL of the server.

uaClient = opcua("opc.tcp://localhost:53530/OPCUA/SimulationServer");

Create OPC UA Client with Hostname and Port Number

Create a client for the server at port 53530 on the local host.

uaClient = opcua("localhost",53530)

Create OPC UA Client and Configure Security Model

Since R2025a

Create a client using the discovery URL of the server and configure the security model.

uaClient = opcua("opc.tcp://MyMachine-4u6B:53530/OPCUA/SimulationServer",...
 MessageSecurityMode="SignAndEncrypt", ChannelSecurityPolicy="Aes256_Sha256_RsaPss");

View client details.

uaClient

uaClient = 

OPC UA Client:

   Server Information:
                     Name: 'SimulationServer@MyMachine-4u6B'
                 Hostname: 'MyMachine-4u6B'
                     Port: 53530
              EndpointUrl: 'opc.tcp://MyMachine-4u6B:53530/OPCUA/SimulationServer'

   Connection Information:
                  Timeout: 10
                   Status: 'Disconnected'
              ServerState: '<Not connected>'

   Security Information:
      MessageSecurityMode: SignAndEncrypt
    ChannelSecurityPolicy: Aes256_Sha256_RsaPss
                Endpoints: [1×11 opc.ua.EndpointDescription]

Create OPC UA Client and Configure Endpoint URL Hostname

Since R2025a

Create a client using the discovery URL of the server.

uaClient = opcua("opc.tcp://240.19.17.56:53530/OPCUA/SimulationServer");

View the endpoint URL returned by the server.

uaClient.EndpointUrl

ans =

    'opc.tcp://192.168.1.2:53530/OPCUA/SimulationServer'

Re-create the client and replace the endpoint URL hostname with discovery URL hostname.

uaClient = opcua("opc.tcp://240.19.17.56:53530/OPCUA/SimulationServer", UseDiscoveryHostname=true);

Verify if the endpoint URL is same as the discovery URL of the client.

uaClient.EndpointUrl

ans =

    'opc.tcp://240.19.17.56:53530/OPCUA/SimulationServer'

Input Arguments

serverInfoObj — OPC UA server information object

opc.ua.ServerInfo object

OPC UA server information object, specified as an opc.ua.ServerInfo object.

Data Types: object

serverUrl — OPC UA server URL

char | string

OPC UA server URL, specified as a character vector or string. The server URL must use the opc.tcp protocol; Industrial Communication Toolbox™ does not support http or https connections to an OPC UA server.

Data Types: char | string

hostname — Server hostname or IP address

char | string

Server hostname or IP address, specified as a character vector or string. A hostname can be short or a fully qualified domain name.

Example: 'localhost'

Data Types: char | string

portnum — Server host port number

numeric

Server host port number, specified as a numeric value.

Example: 5000

Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64

Name-Value Arguments

Specify optional pairs of arguments as Name1=Value1,...,NameN=ValueN, where Name is the argument name and Value is the corresponding value. Name-value arguments must appear after other arguments, but the order of the pairs does not matter.

Example: uaClient = opcua("opc.tcp://localhost:53530/OPCUA/SimulationServer", MessageSecurityMode="Sign", ChannelSecurityPolicy="Basic256Sha256");

MessageSecurityMode — Client message security mode

"SignAndEncrypt" | "Sign" | "None"

Since R2025a

Client message security mode, specified as "SignAndEncrypt" or "Sign" or "None". By default, the function chooses the highest message security mode available on the server.

Example: uaClient = opcua("localhost", 53530, MessageSecurityMode="Sign");

Data Types: char | string

ChannelSecurityPolicy — Client channel security policy

"Aes256_Sha256_RsaPss" | "Basic256Sha256" | "Aes128_Sha256_RsaOaep" | "None"

Since R2025a

Client channel security policy, specified as "Aes256_Sha256_RsaPss", "Basic256Sha256", "Aes128_Sha256_RsaOaep" or "None". By default, the function chooses the highest channel security policy available on the server.

Example: uaClient = opcua("localhost", 53530, ChannelSecurityPolicy="Basic256Sha256");

Data Types: char | string

Note

Security Considerations: To enable a secure communication with an OPC UA server, use a strong channel security policy and message security mode.

You can expose your system to security risks when you set the MessageSecurityMode and ChannelSecurityPolicy to "None". Use this setting only in a trusted environment.

If you need to connect to an OPC UA server that does not support a security policy, request the server administrator to enable a strong channel security policy and message security mode for the server. These settings enable encryption and authentication and safeguard your data and operations.

UseDiscoveryHostname — Option to replace endpoint URL hostname with input URL hostname

false (default) | true

Since R2025a

Option to replace the endpoint URL hostname with the input hostname or IP address provided in serverUrl, specified as one of these:

• true: The function replaces the hostname in the endpoint URL returned by the server with the input hostname or IP address provided in serverUrl.

• false: The function retains the endpoint URL provided by the server.

Example: uaClient = opcua("opc.tcp://DNShost:53530/OPCUA/SimulationServer", UseDiscoveryHostname=true);

Data Types: logical

Note

Security Considerations: You modify the endpoint URL returned by the server when you set the UseDiscoveryHostname to true. Use this setting only in a trusted environment.

If you need to connect to an OPC UA server through a NAT router, ensure that the server returns all discoverable endpoints to a calling client.

Output Arguments

uaClient — OPC UA client

opc.ua.Client object

OPC UA client, returned as an opc.ua.Client object, with these properties.

Property	Description
Server Information
Name	Server name.
Hostname	Server hostname or IP address.
Port	Port number used for TCP/IP connections to the server.
EndpointUrl	URL to use for connection to the server.
Connection Information
Timeout	Time to wait for all operations on the server to complete.
Status	Status of the client: 'Connected' or 'Disconnected'.
ServerState	State of the server: 'Running', 'Failed', 'No Configuration', 'Suspended', 'Shutdown', 'Test', 'Comms Fault', 'Unknown'.
Security Information
MessageSecurityMode	Message security mode specified for connection.
ChannelSecurityPolicy	Channel security policy specified for connection.
Endpoints	Available endpoints for server.
Server Limits (These properties are available only after you connect the client to the server)
MinSampleRate	Minimum sample rate in seconds that the server can generally support.
MaxReadNodes	Maximum number of nodes supported per read operation.
MaxWriteNodes	Maximum number of nodes supported per write operation.
MaxHistoryReadNodes	Maximum number of nodes supported by historical read operations.
MaxHistoryValuesPerNode	Maximum history values returned per node in historical read operations.

Version History

Introduced in R2015b

R2025a: Configure Security Model and Endpoint URL Hostname

Use the enhanced opcua function to configure security model and endpoint URL hostname for an OPC UA client.