"Timeout occurred while processing the request." on Method Call request

While trying to call a method on an OPC server with a custom type I always receive a “Timeout occurred while processing the request.” error. Below is the code for the request, it follows the logic you used for the method call in the IntegrationTests class.

  protected override async Task ExecuteAsync(CancellationToken stoppingToken)
   { 

            // describe this client application.
            var clientDescription = new ApplicationDescription
            {
                ApplicationName = "Workstation.UaClient.FeatureTests",
                ApplicationUri = $"urn:{System.Net.Dns.GetHostName()}:Workstation.UaClient.FeatureTests",
                ApplicationType = ApplicationType.Client
            };

            var channel = new UaTcpSessionChannel(
              this.localDescription,
              null,
              new AnonymousIdentity(),
             "opc.tcp://192.168.0.254:4840",
              SecurityPolicyUris.None,
              loggerFactory: this.loggerFactory,
              additionalTypes: new[] { typeof(ScanSettings) });
            try
            {
                // try opening a session and reading a few nodes.
                await channel.OpenAsync();

                Console.WriteLine($"Opened session with endpoint '{channel.RemoteEndpoint.EndpointUrl}'.");
                Console.WriteLine($"SecurityPolicy: '{channel.RemoteEndpoint.SecurityPolicyUri}'.");
                Console.WriteLine($"SecurityMode: '{channel.RemoteEndpoint.SecurityMode}'.");
                Console.WriteLine($"UserIdentityToken: '{channel.UserIdentity}'.");
                var readRequest = new ReadRequest { NodesToRead = new[] { new ReadValueId { NodeId = NodeId.Parse("ns=4;i=6030"), AttributeId = AttributeIds.Value } } };
                var readResult = await channel.ReadAsync(readRequest);
                var serverStatus = readResult.Results[0].GetValueOrDefault<ServerStatusDataType>();

                var set = new ScanSettings
                {
                    Duration = 500,
                    Cycles = 10
                };
                var request = new CallRequest
                {
                    MethodsToCall = new[] {
                        new CallMethodRequest
                        {
                            ObjectId =  NodeId.Parse("ns=2;i=5001"),
                            MethodId =  NodeId.Parse("ns=4;i=7010"),
                            InputArguments = new [] { new ExtensionObject(set)}.ToVariantArray()
                        }
                    }
                };
 
                var response = await channel.CallAsync(request);
                var result = response.Results[0].OutputArguments[0].GetValueOrDefault<ScanSettings>();

                Console.WriteLine($"\nClosing session '{channel.SessionId}'.");
                await channel.CloseAsync();
            }
            catch (Exception ex)
            {
                await channel.AbortAsync();
                Console.WriteLine(ex.Message);
            }
        }

    [DataTypeId("ns=3;i=6044")]
    [BinaryEncodingId("ns=3;i=5015")]
    internal class ScanSettings : Structure
    {
        public uint Duration { get; set; }
        public int Cycles { get; set; }
        public override void Encode(IEncoder encoder)
        {
            encoder.WriteUInt32("Duration", this.Duration);
            encoder.WriteInt32("Cycles", this.Cycles);
        }

        public override void Decode(IDecoder decoder)
        {
            this.Duration = decoder.ReadUInt32("Duration");
            this.Cycles = decoder.ReadInt32("Cycles");
        }

        public override string ToString() => $"{{ Duration={this.Duration}; Cycles={this.Cycles}; }}";
    }

Any help would be awesome. Thank you

[awcullen]

Try this out. I got the idea from https://reference.opcfoundation.org/v104/Core/docs/Part6/5.2.7/

    [DataTypeId("nsu=http://opcfoundation.org/UA/AutoID/;i=3010")]
    [BinaryEncodingId("nsu=http://opcfoundation.org/UA/AutoID/;i=5015")]
    internal class ScanSettings : Structure
    {
        public Double Duration { get; set; }
        public Int32 Cycles { get; set; }
        public Boolean DataAvailable { get; set; }
        public LocationTypeEnumeration? LocationType { get; set; }

        public override void Encode(IEncoder encoder)
        {
            UInt32 optionFlags = 0;
            if (this.LocationType.HasValue)
            {
                optionFlags |= 1;
            }
            encoder.WriteUInt32("", optionFlags);
            encoder.WriteDouble("Duration", this.Duration);
            encoder.WriteInt32("Cycles", this.Cycles);
            encoder.WriteBoolean("DataAvailable", this.DataAvailable);
            if ((optionFlags & 1) != 0)
            {
                encoder.WriteInt32("LocationType", (int)this.LocationType);
            }
        }

        public override void Decode(IDecoder decoder)
        {
            UInt32 optionFlags = decoder.ReadUInt32("");
            this.Duration = decoder.ReadDouble("Duration");
            this.Cycles = decoder.ReadInt32("Cycles");
            this.DataAvailable = decoder.ReadBoolean("DataAvailable");
            if ((optionFlags & 1) != 0)
            {
                this.LocationType = (LocationTypeEnumeration)decoder.ReadInt32("LocationType");
            } 
            else
            {
                this.LocationType = null;
            }
        }

        public override string ToString() => $"{{ Duration={this.Duration}; Cycles={this.Cycles}; DataAvailable={this.DataAvailable}; LocationType={this.LocationType};}}";
    }

    public enum LocationTypeEnumeration
    {
        NMEA = 0,
        LOCAL = 1,
        WGS84 = 2,
        NAME = 3
    }

[kaasmdfs]

Thanks everyone for the help, I managed to get a solution that used a version of what Andrew showed for the Unions that solved that one issue.

   [DataTypeId("ns=3;i=6034")]
    [BinaryEncodingId("ns=3;i=5013")]
    public class Location : Union
    {
        public int? SwitchField { get; set; }
        public string NMEA { get; set; }
        public LocalCoordinate Local { get; set; }
        public WGS84Coordinate WGS84 { get; set; }
        public string Name { get; set; }

        public override void Encode(IEncoder encoder)
        {
            encoder.WriteInt32("SwitchField", this.SwitchField.Value);
        }

        public override void Decode(IDecoder decoder)
        {
            this.SwitchField = decoder.ReadInt32("SwitchField");
            switch (SwitchField)
            {
                case 0:

                    break;
                case 1:
                    this.NMEA = decoder.ReadString("NMEA");
                    break;
                case 2:
                    this.Local = decoder.ReadExtensionObject<LocalCoordinate>("Local");
                    break;
                case 3:
                    this.WGS84 = decoder.ReadExtensionObject<WGS84Coordinate>("WGS84");
                    break;
                case 4:
                    this.Name = decoder.ReadString("Name");
                    break;
                default:
                    this.SwitchField = 0;
                    break;
            }

        }

     
    }

The rest of it was solved by adding a blank ReadInt32 at the beginning of the decoding, not sure why it was needed exactly, and I also had a few properties out of order from their specification. I did not realize that the property order had to be exactly as defined in the XML.