OPCUA Plugin

Installation Steps:

(1) Use listRemotePlugins to check plugin information in the plugin repository

login("admin", "123456")
listRemotePlugins(, "http://plugins.dolphindb.com/plugins/")

(2) Invoke installPlugin for plugin installation

installPlugin("opcua")

It returns <path_to_OPCUA_plugin>/PluginOPCUA.txt.

getOpcServerList

Syntax

Parameters

• serverUrl is a string indicating the server URL. For example opc.tcp://127.0.0.1:53530/OPCUA/SimulationServer/.

Details

Get a list of OPC servers. It returns a table with five columns:

• ServerUri: The unique identifier for the server.

• ServerName: The server name.

• ProductUri: The unique identifier for the product.

• Type: The server type.

• DiscoveryUrl: URL(s) for the discovery endpoints. Separate multiple URLs with semicolon ";".

Examples

opcua::getOpcServerList(serverUrl);

getOpcEndPointList

Syntax

Parameters

• serverUrl is a string indicating the server URL. For example opc.tcp://127.0.0.1:53530/OPCUA/SimulationServer/.

Details

Get a list of OPC server endpoints. It returns a table with five columns:

• endpointUrl: The endpoint URL.

• transportProfileUri: The unique identifier of the transport configuration.

• securityMode: The security mode.

• securityPolicyUri: The unique identifier of security policy.

• securityLevel: The security level.

Examples

opcua::getOpcEndPointList(serverUrl);

connect

Syntax

Parameters

• endPointUrl is a string specifying the endpoint URL to which the client attempted to connect.

• clientUri is a string representing the unique identifier of client. If certificate is specified, the uri must be consistent.

• userName is a string representing the username. It can be skipped if server is not set.

• userPassword is a string representing the user password.

• securityMode is a string indicating the security mode for connection. It must be "None" (default), "Sign", or "SignAndEncrypt".

• securityPolicy is a string representing the security algorithm for connection. It must be "None" (default), "Basic256", "Basic128Rsa15", or "Basic256Sha256". If using "Basic256", "Basic128Rsa15", or "Basic256Sha256" encryption, certificate and privateKey must also be specified. The certificate and privateKey under ./open62541/cert/ directory can be used, or custom certificate and key can be used (tools of open62541 can be used to generate certificates).

• certificatePath is a string specifying the certificate path. It can be omitted if encrypted communication is not used.

• privateKeyPath is a string specifying the private key path. It can be omitted if encrypted communication is not used.

Details

Connect to an OPC server. The method returns a connection that can be explicitly closed by calling the close function. If encrypted communication is enabled, a trusted certificate must be specified on the server. If using encryption with the Prosys local simulation server, a user needs to be added in the Users interface with a username and password. For example, for username "user1" and password "123456", trust open62541server@localhost in the Certificates interface.

Examples

connection=opcua::connect(serverUrl,"myClient");
connection=opcua::connect(serverUrl,"myClient","user1","123456");
connection=opcua::connect(serverUrl,"urn:opcua.client.application","user1","123456","SignAndEncrypt","Basic128Rsa15","./open62541/cert/client_cert.der","./open62541/cert/client_key.der");

browseNode

Syntax

Parameters

• connection is the return value of method connect.

Details

Return a table of all nodes, with 2 columns nodeNamespace and nodeIdString.

Examples

connection=opcua::connect(serverUrl,"myClient");
opcua::browseNode(connection);

readNode

Syntax

Parameters

• connection is the return value of method connect.

• nodeNamespace is an INT scalar or vector indicating the node namespace(s).

• nodeIdString is a STRING scalar or array indicating the node ID(s).

• table stores the accessed node values. If a table is specified, all values are inserted into the table. If multiple tables are specified, it must be a tuple of tables and its size must match the number of nodes. The value of each node is inserted into the corresponding table. If no table is specified, the method returns a table that stores the node values.

Details

Read the node value synchronously. An OPC connection must be established first before using the method. The result returned for each node includes four values:

• node id: The node ID, i.e., nodeNamespace and nodeIdString concatenated by ":".

• value: The node value.

• timestamp: The source timestamp in local time.

• status: The status of the node value.

Examples

t1 = table(200:0,`nodeID`value`timestamp`status, [SYMBOL, INT, TIMESTAMP, SYMBOL])
opcua::readNode(conn, 3, "Counter",t1)
opcua::readNode(conn, 3, ["Counter","Expression","Random","Sawtooth"],t1)
t2 = table(200:0,`nodeID`value`timestamp`status`nodeID`value`sourceTimestamp`status,[SYMBOL, INT, TIMESTAMP, SYMBOL，SYMBOL, INT, TIMESTAMP, SYMBOL])
opcua::readNode(conn, 1, ["test1","test4"],t2)
t3 = table(200:0,`nodeID`value`timestamp`status, [SYMBOL, INT, TIMESTAMP, SYMBOL])
t4 = table(200:0,`nodeID`value`timestamp`status, [SYMBOL, INT, TIMESTAMP, SYMBOL])
t5 = table(200:0,`nodeID`value`timestamp`status, [SYMBOL, INT, TIMESTAMP, SYMBOL])
opc::readNode(conn, 1, ["test1","test4", "test9"],[t3,t4,t5]) 

writeTag

Syntax

Parameters

• connection is the return value of method connect.

• nodeNamespace is an INT scalar or array indicating the node namespace(s).

• nodeIdString is a string scalar or array indicating the node ID(s).

• value is the value(s) to write to the node(s).

Details

Write value(s) to one or multiple nodes synchronously. An exception will be thrown if the write type is incorrect.

Examples

opcua::writeNode(conn,1,"testwrite.test1",1)
opcua::writeNode(conn,1,["testwrite.test5","testwrite.test6"],[33,11])
opcua::writeNode(conn,1,"testwrite.test2",[1,2,3,4]) //one-dimensional array
m = matrix([[1,2,3],[1,2,3]])
opcua::writeNode(conn,1,"testwrite.test3",m) //two-dimensional array

subscribe

Syntax

Parameters

• connection is the return value of method connect.

• nodeNamespace is an INT scalar or vector indicating the node namespace(s).

• nodeIdString is a STRING scalar or vector indicating the node ID(s).

• handler is the callback function or table or will be invoked when value changes.

Details

Subscribe to the changes of node values. Note that currently one subscription uses one connection exclusively, i.e., if subscribe is called on a connection, that connection cannot be used for readNode, writeNode, etc.

Examples

t1 = table(200:0,`nodeID`value`timestamp`status, [SYMBOL, INT, TIMESTAMP, SYMBOL])
conn1=opcua::connect(serverUrl，"myClient")
opcua::subscribe(conn1,1,"test.subscribe",t1)
t2 = table(200:0,`nodeID`value`timestamp`status, [STRING, INT, TIMESTAMP, STRING])
conn2=opcua::connect(serverUrl，"myClient")
opcua::subscribe(conn2, 3, ["Counter","Expression","Random","Sawtooth"],t2)
t3 = table(200:0,`nodeID`value`timestamp`status, [SYMBOL, BOOL, TIMESTAMP, SYMBOL])
def callback1(mutable t, d) {
	t.append!(d)
}
conn3=opcua::connect(serverUrl，"myClient")
opcua::subscribe(conn3,2, "testsubscribe",callback1{t3})

getSubscriberStat

Syntax

Details

Get status of all current subscriptions, including:

• subscriptionId: The subscription ID.

• user: The user who created the subscription.

• endPointUrl: The endpoint URL of the connection.

• clientUri: The client identifier of the connection.

• nodeID: All subscribed nodes, represented as "nodeNamespace:nodeIdString" for each node and separated by a semicolon ';'.

• createTimestamp: The time when the subscription was created.

• receivedPackets: Number of packets received for the subscription.

• errorMsg: Latest error message when processing messages.

Examples

opcua::getSubscriberStat()

unsubscribe

Syntax

Parameters

• subscription is the return value of method connect or the subscription identifier returned by getSubscriberStat.

Details

Cancel the client's subscription.

Examples

opcua::unsubscribe(subscription)

close

Syntax

Parameters

• connection is the return value of method connect.

Details

Close the connection to the OPC server.

Examples

opcua::close(connection)

Download Precompiled Binaries

You can download the pre-built binaries libPluginOPCUA.dll or libPluginOPCUA.so from the bin directory.

On Linux, set the required dynamic library path for the plugin runtime:

export LD_LIBRARY_PATH=/path/to/PluginOPCUA:$LD_LIBRARY_PATH

For Windows, you must specify the absolute path during loading, and use "\\" or "/" instead of "\" in the path.

Compile from Source

You need to first compile the mbedtls static library and the open62541 dynamic library. Steps are:

On Windows:

• Install mbedtls

  (1) Download the latest mbedtls project from GitHub:

  git clone https://github.com/ARMmbed/mbedtls.git

  (2) Compile to static library using CMake:

  cd mbedtls
  mkdir build
  cd build
  cmake .. -G "MinGW Makefiles" -DENABLE_PROGRAMS=OFF
  make

  The compiled static libraries are under mbedtls/build/library, named libmbedcrypto.a, libmbedx509.a, and libmbedtls.a.

• Install open62541

  (1) Download the 1.0 version of open62541 project from GitHub:

  git clone https://github.com/open62541/open62541.git
  git submodule update --init --recursive
  cd open62541
  git checkout 1.0

  (2) Compile to dynamic library using CMake:

  cd mbedtls
  mkdir build
  cd build
  cmake .. -G "MinGW Makefiles" -DENABLE_PROGRAMS=OFF
  make

  Note: The paths for -DMBEDTLS_INCLUDE_DIRS and -DMBEDTLS_LIBRARIES must be replaced with actual path.

On Linux Ubuntu:

• Install mbedtls

  sudo apt-get install libmbedtls-dev

• Install open62541 same as on Windows, no need to specify -DMBEDTLS_INCLUDE_DIRS and -DMBEDTLS_LIBRARIES.

On Linux Centos:

• Install mbedtls:

  yum install mbedtls-devel

• Install open62541 same as on Windows, no need to specify -DMBEDTLS_INCLUDE_DIRS and -DMBEDTLS_LIBRARIES.

Use cmake to build libPluginOPCUA

• (Skip this step on Linux) Copy libmbedcrypto.a, libmbedx509.a, libmbedtls.a from mbedtls/build/library to ./lib directory. Copy mbedtls and psa folders under mbedtls/include to ./include directory.

• Copy .dll files or all .so files from open62541/build/bin to ./lib directory. Copy folders under open62541/build/src_generated/, open62541/include/, open62541/plugins/include/ to ./include directory, and folders under open62541/arch/ to ./include/open62541 directory.

• Use cmake to build libPluginOPCUA. -G is not required on Linux.

  mkdir build
  cd build
  cmake .. -G "MinGW Makefiles" -DLIBDOLPHINDB="path_to_libdolphindb"
  make

  Note: The path for -DLIBDOLPHINDB must be replaced with actual path.

• Copy libopen62541.dll or libopen62541.so to the build directory.