Building the Device Support Module

This is a standard EPICS module.

Clone the repository:

git clone https://github.com/epics-modules/opcua.git
cd opcua

(On Linux:) Configure the C++ Standard: Configure the compiler on Linux to use the C++11 standard by adding
```
USR_CXXFLAGS_Linux += -std=c++11
```
to the CONFIG_SITE file (or one of the host/target specific site configuration files). It is preferable to set this option globally in EPICS Base.
Configure the module: Inside the configure subdirectory or one level above the TOP location, create a file RELEASE.local that sets EPICS_BASE (and optionally GTEST) to their absolute paths inside your EPICS installation. (The GTEST module is needed to compile and run the unit tests. Not defining it produces a clean build, but without any tests.)

The configuration necessary when building against a specific client library is documented in the relevant section: Configuring Device Support for open62541 and Configuring Device Support for UA SDK.
Build the module:
```
make
```