client.hpp File Reference

OPC UA client implementing ifw::fnd::defs::ICommAdapter. More...

#include <memory>
#include <ifw/fnd/defs/iCommAdapter.hpp>

Go to the source code of this file.

Classes
class	eso::uatools::Client
	OPC UA client implementing ifw::fnd::defs::ICommAdapter. More...
struct	eso::uatools::Client::DataTypeInfo
	Result of a DataType lookup on a node. More...

Namespaces
namespace	eso
namespace	eso::uatools

Detailed Description

OPC UA client implementing ifw::fnd::defs::ICommAdapter.

Copyright

SPDX-FileCopyrightText: 2026 European Southern Observatory (ESO) SPDX-License-Identifier: LGPL-3.0-only

eso::uatools::Client is the public-facing class. It implements the protocol-agnostic ICommAdapter contract over OPC UA. The choice of open62541 as the underlying SDK is an implementation detail and is NOT exposed in this header — callers see only ifw::fnd::defs types.

Multiple instances are supported: typically one Client per OPC UA server connection. Instances do not share state with each other.

Usage:

#include <eso/uatools/ualib/client.hpp>
using namespace ifw::fnd::defs;
 
eso::uatools::Client client;
 
ConnectionOptions opts;
opts.endpoint = "opc.tcp://plc-1.lan:4840";
opts.properties.Set("username", "operator");
opts.properties.Set("password", "******");
client.Configure(opts);
client.Connect();
 
ReadRequest req;
req.items.push_back({"ns=2;s=Temperature", {}});
ReadResult res = client.Read(req);
if (res) {
    auto& dv = res.items.front().data.value();
    double t = std::get<double>(dv.value);
}