# erlopen62541

Erlang port for OPC UA Client functionality based on
[open62541](https://github.com/open62541/open62541) project.

# Compilation

As prerequisite [open62541](https://github.com/open62541/open62541) framework should be installed and
simple example of C++ client/server could be built.

```bash
$ rebar3 clean && rebar3 compile
```

# Basic usage

After successfull compilation shell could be used for easy checking.

NOTE: As this is client functionality, valid and accessible OPC UA server or OPC UA server emulator
is required for completing this step.

Initial version of port has been tested with Prosys OPC Siluation Server.

```bash
$ rebar3 shell
```

```erlang
1> % open port
1> f(P), {ok, P} = erlopen62541:start_link().
{ok, <0.137.0>}
2> % connect to server
2> erlopen62541:connect(P, <<"opc.tcp://192.168.1.33:53530/OPCUA/SimulationServer">>).
ok
3> % read system namespace values
3> erlopen62541:read_node(P, 0, 2258).
{datetime,<<"25/8/2020 6:21:5.751">>}
4> % read user namespace values
erlopen62541:read_node(P, 3, 1001).
{integer,23}
```

# Dependency to project

Following setting of rebar simple adds port as dependency to the project:

```erlang
{deps, [
  ...
  {erlopen62541, {git, "https://git.faceplate.io/nickolay.kovalev/erlopen62541.git", {branch, master}}},
  ...
]}.
```