/// <summary>
/// Get the configuration for the module (in this case the OPC-UA Connection String for the Device).
/// </summary>
private async Task <ModuleConfig> GetConfiguration(DeviceClient deviceClient)
{
// First try to get the config from the Module twin
var twin = await deviceClient.GetTwinAsync();
if (twin.Properties.Desired.Contains(OpcUAConnectionStringKey))
{
opcUAConnectionString = (string)twin.Properties.Desired[OpcUAConnectionStringKey];
}
var moduleConfig = new ModuleConfig(opcUAConnectionString);
await UpdateDesiredProperties(twin.Properties.Desired, deviceClient, moduleConfig);
Console.WriteLine(moduleConfig);
return(moduleConfig);
}
private async Task <Session> OpcBoot(ModuleConfig moduleConfig)
{
Console.WriteLine($"EdgeOpcUAClient - Message received at {DateTime.Now.ToLongTimeString()}");
while (true)
{
try
{
return(await ConnectToServer(moduleConfig.OpcUAConnectionString));
}
catch (Exception ex)
{
Console.WriteLine($"Message: {ex.Message}");
Console.WriteLine($"Error on connection to OPC UA endpoint. Retry in {retryInterval.TotalSeconds} seconds");
await Task.Delay(retryInterval);
}
}
}
/// <summary>
/// Initializes the DeviceClient and sets up the callback to receive messages
/// </summary>
private async Task <IDisposable> Init(string connectionString)
{
await Task.Delay(TimeSpan.FromSeconds(10));
// Use Mqtt transport settings.
// The RemoteCertificateValidationCallback needs to be set
// since the Edge Hub currently uses a self signed SSL certificate.
ITransportSettings[] settings =
{
new MqttTransportSettings(TransportType.Mqtt_Tcp_Only)
{
RemoteCertificateValidationCallback = (sender, certificate, chain, sslPolicyErrors) => true
}
};
// Open a connection to the Edge runtime
DeviceClient deviceClient =
DeviceClient.CreateFromConnectionString(connectionString, settings);
await deviceClient.OpenAsync();
Console.WriteLine("EdgeOpcUAClient - Opened module client connection");
ModuleConfig moduleConfig = await GetConfiguration(deviceClient);
await deviceClient.SetDesiredPropertyUpdateCallbackAsync((props, context) => UpdateDesiredProperties(props, context, moduleConfig), deviceClient);
var session = await OpcBoot(moduleConfig);
await deviceClient.SetInputMessageHandlerAsync(
"input1",
(message, context) => SendDataToDevice(deviceClient, session, message, moduleConfig),
null);
Console.WriteLine("EdgeOpcUAClient - callback for route \"input1\" registered");
return(Disposable.Create(() =>
{
session.Close();
session.Dispose();
}));
}
// here you have to implement the message conversion for the OPC device.
private async Task <MessageResponse> SendDataToDevice(DeviceClient deviceClient, Session session, Message message, ModuleConfig moduleConfig)
{
return(await Task.Run(() => {
byte[] messageBytes = message.GetBytes();
string messageString = Encoding.UTF8.GetString(messageBytes);
Console.WriteLine($"Message received: {messageString}");
// send it to the OPC-UA device using the session.
// session.Write(null, somevalcol, out _, out _);
return MessageResponse.Completed;
}));
}
// check for module twin updates. Below is a sample value check
private async Task UpdateDesiredProperties(TwinCollection desiredproperties, object usercontext, ModuleConfig moduleConfig)
{
if (desiredproperties.Contains(OpcUASampleValueKey))
{
string value = desiredproperties[OpcUASampleValueKey].ToString();
if (!string.IsNullOrEmpty(value))
{
moduleConfig.OpcUASampleValue = value;
}
Console.WriteLine($"{nameof(ModuleConfig.OpcUASampleValue)}: { moduleConfig.OpcUASampleValue}");
}
if (usercontext is DeviceClient deviceClient)
{
await deviceClient.UpdateReportedPropertiesAsync(CreateTwinCollectionFromModuleConfig(moduleConfig));
}
}
private TwinCollection CreateTwinCollectionFromModuleConfig(ModuleConfig moduleConfig)
{
return(new TwinCollection(JsonConvert.SerializeObject(moduleConfig)));
}