Create driver extension

Driver Extensions are .NET Standard 2.0 or .NET Core 2.1 libraries (*.dll) that must be located within the zenon installation. If additional dependencies are used, they must be located in the same directory. You can use a development environment of your choice, in this document we use Visual Studio 2019.

Create a new .NET Standard 2.0 or .NET Core 2.1 Library

With Visual Studio according project templates are available out of the box.

Set references to Driver API

All needed types to create a driver extension are located in assembly C:\Program Files (x86)\COPA-DATA\zenon 10\DriverFramework\CopaData.Drivers.Contracts.dll

Hint: Use $(registry:HKEY_LOCAL_MACHINE\SOFTWARE\COPA-DATA\DataDir@ProgramDir32_10000)DriverFramework\CopaData.Drivers.Contracts.dll in the Visual Studio project file to target your installation directory independent of your installation.

See sample here

Create DriverExtension Class

A driver extension class is a public .NET class, that implements interface CopaData.Drivers.Contracts.IDriverExtension. The next listing shows an implementation of the class in a very basic way. The interface is designed to work in a asynchronous way.

  using CopaData.Drivers.Contracts;
  public class DriverExtension : IDriverExtension
  {
    private ILogger _logger;
    private IValueCallback _valueCallback;

    public Task InitializeAsync(ILogger logger, IValueCallback valueCallback, string configFilePath)
    {
      _logger = logger;
      _valueCallback = valueCallback;

      return Task.CompletedTask;
    }

    public Task ShutdownAsync()
    {
      return Task.CompletedTask;
    }

    public Task<bool> SubscribeAsync(string symbolicAddress)
    {
      return Task.FromResult(true);
    }

    public Task UnsubscribeAsync(string symbolicAddress)
    {
      return Task.CompletedTask;
    }

    public Task ReadAllAsync()
    {
      return Task.CompletedTask;
    }

    public Task<bool> WriteStringAsync(string symbolicAddress, string value, DateTime dateTime, StatusBits status)
    {
      return Task.FromResult(true);
    }

    public Task<bool> WriteNumericAsync(string symbolicAddress, double value, DateTime dateTime, StatusBits status)
    {
      return Task.FromResult(true);
    }
  }

• InitializeAsync: The driver is initialized (e. g. on Runtime start)
• ShutdownAsync: The driver is shutting down (e. g. on Runtime exit)
• SubscribeAsync: This method is called by zenon, when a variable (by using the symbolic address) is requested (variable is adviced by showing on a screen, using in archives, etc.)
• UnsubscribeAsync: This method is called by zenon, when a variable (by using the symbolic address) is not needed any more (e. g. a screen switch to another screen or stopping an archive)
• WriteStringAsync: This method is called by zenon, when the string value of a variable is set.
• WriteNumericAsync: This method is called by zenon, when the numeric/boolean value of a variable is set.

Deployment

Driver Extensions must be located in a sub directory of C:\Program Files (x86)\COPA-DATA\zenon 10\DriverExtensions folder, for example C:\Program Files (x86)\COPA-DATA\zenon 10\DriverExtensions\MyDriverExtension.

The folder must contain the Driver Extension assembly (the project previously created) and all dependencies.

Copy files to DriverExtensions-Folder by using a PostEvent-Step

Ensure that you have write access rights to folder C:\Program Files (x86)\COPA-DATA\zenon 10\DriverExtensions (e. g. by starting Visual Studio in Admin-Mode.

In project properties, add a Post-Build event, here a sample:

if not exist "$(registry:HKEY_LOCAL_MACHINE\SOFTWARE\COPA-DATA\DataDir@ProgramDir32_8200)DriverExtensions\BasicSample" mkdir "$(registry:HKEY_LOCAL_MACHINE\SOFTWARE\COPA-DATA\DataDir@ProgramDir32_8200)DriverExtensions\BasicSample"
copy /y "$(TargetDir)\*.*" "$(registry:HKEY_LOCAL_MACHINE\SOFTWARE\COPA-DATA\DataDir@ProgramDir32_8200)DriverExtensions\BasicSample"

Ensure that all dependencies are included

By default, the build process does not copy all dependencies of .NET Standard or .NET Core libraries to the output directory. To ensure that all dependencies are copied, add the following XML tag to the driver extension project:

<CopyLocalLockFileAssemblies>true</CopyLocalLockFileAssemblies>

See sample here