Synopsis#

Methods#

def __init__()
def createClient()

Static functions#

def availableBackends()

Note

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Detailed Description#

QOpcUaProvider allows the user to create an instance of QOpcUaClient by loading a QOpcUaPlugin using the Qt plugin system.

Example#

This code creates a client using the first available backend:

QOpcUaProvider provider;
QStringList available = provider.availableBackends();
if (!available.isEmpty()) {
    QOpcUaClient *client = provider.createClient(available[0]);
    if (client)
        qDebug() << "Client successfully created";
}

__init__([parent=None])#

Parameters:: parent – QObject

Creates a new OPC UA provider with a given parent.

static availableBackends()#

Return type:: list of strings

Returns a QStringList of available plugins.

createClient(backend[, backendProperties=QVariantMap()])#

Parameters:

backend – str
backendProperties – Dictionary with keys of type .QString and values of type QVariant.

Return type:

QOpcUaClient

Returns a pointer to a QOpcUaClient object by loading the selected backend as a plugin and creating a client object. If the plugin loading fails, nullptr is returned instead.

The user is responsible for deleting the returned QOpcUaClient object when it is no longer needed.

The optional argument backendProperties can be used to pass custom backend specific settings as key value pairs. Those settings are specific to the backend being instantiated.

Available settings are

Setting string

Backend

Description

minimumClientIterateIntervalMs

open62541

This parameter is no longer evaluated by the backend and has been replaced by clientIterateIntervalMs.

clientIterateIntervalMs

open62541

Defines the client iterate interval for the backend. If the client is causing too much CPU load, setting this value higher than the default will reduce the CPU load at the price of an increased response time to service requests and value updates from subscriptions. The default value is 50ms.

asyncRequestTimeoutMs

open62541

Defines the timeout for asynchronous requests to an OPC UA server. If the server doesn’t reply to a service request before the timeout occurs, the service call fails and the finished signal will contain a bad status code. The default value is 15000ms.

Setting string	Backend	Description
minimumClientIterateIntervalMs	open62541	This parameter is no longer evaluated by the backend and has been replaced by `clientIterateIntervalMs`.
clientIterateIntervalMs	open62541	Defines the client iterate interval for the backend. If the client is causing too much CPU load, setting this value higher than the default will reduce the CPU load at the price of an increased response time to service requests and value updates from subscriptions. The default value is 50ms.
asyncRequestTimeoutMs	open62541	Defines the timeout for asynchronous requests to an OPC UA server. If the server doesn’t reply to a service request before the timeout occurs, the service call fails and the finished signal will contain a `bad` status code. The default value is 15000ms.