C# can not read calculatorCode for PLANE LATITUDE

[763305292]

Hi Sir,

Thank you for the DLLs you made so that we can track different variables beyond what SimConnect allows.

However, I encountered an issue where I cannot listen to (A:PLANE LATITUDE, degrees) using saveDataRequest. It always returns 0 when I try to convert the data, but the value is correct when I use 'client.getVariable(new VariableRequest("PLANE LATITUDE", "degrees", 0), out double fResult)' to retrieve the latitude.

Could you please help me? The code is as follows and thank you for your support:

var hr = client.saveDataRequest( new DataRequest( requestId: (uint)Requests.Latitude, resultType: CalcResultType.Double, calculatorCode: $"(A:PLANE LATITUDE,degrees)", valueSize: 64, period: UpdatePeriod.Tick, interval: 0, deltaEpsilon: -1.0f ) ); if (hr != HR.OK) Log($"returned error result {hr}", "!!");

[mpaperno]

Hi,

I think the negative deltaEpsilon value is incorrect (is there anything in the logs about that?). Also the latitude deltas will normally be quite small fractions, so filtering on whole degrees is probably undesirable (but I'm not sure what you're trying to do with the -1 value there).

If you do want to use deltaEpsilon feature then I would also remove the valueSize property since that is otherwise automatically set by specifying the CalcResultType.Double result type (or use the ValueTypes.DATA_TYPE_DOUBLE constant).

Is there any particular reason you want to use RPN to subscribe to this value? It is more efficient to request the 'A' variable type directly.

I maybe don't quite understand what you mean by

It always returns 0 when I try to convert the data

Do I understand that your OnDataReceived event handler does get called, but checking DataRequestRecord.data in the handler converts to zero? And/or can you show some more code to explain what you mean by "returns?"

Cheers,
-Max

[763305292]

Thank you for your reply.

You're right, Sir. The '0' result is what I received from the OnDataReceived event's DataRequestRecord.data when I convert it into a float.

The reason why I use RPN is that I want to read some RPN from a JSON file when I can match the details for a specific aircraft type, like this:
if (string.IsNullOrEmpty(SimulatorManager.Instance.SimAircraftConfig?.DataVHF1Frequency))
{
code = $"(A:COM ACTIVE FREQUENCY:1,MHz)";
}
else
{
code = SimulatorManager.Instance.SimAircraftConfig?.DataVHF1Frequency;
}
client.saveDataRequest(
new DataRequest(
requestId: (uint)Requests.VHF1Frequency,
resultType: CalcResultType.Double,
calculatorCode: code,
valueSize: 32,
period: UpdatePeriod.Tick,
interval: 0,
deltaEpsilon: -1.0f
)
);

Anyway, now I can receive latitude correctly since I used simVarName.

Thanks again for your assistance.

[mpaperno]

Hi, thanks for the details.

when I convert it into a float.

Wait, do you mean an actual float type? Because the value was stored as a double (64 bits), so reading it back as a float would only return the first 32 bits of the data (and try to cast that to float type).

The reason why I use RPN is that I want to read some RPN from a JSON file when I can match the details for a specific aircraft type

Ah, that makes sense. RPN is nicely flexible that way!

Anyway, now I can receive latitude correctly since I used simVarName.

Well it's more efficient, as I mentioned, but you should be able to do what you originally intended as well (with the RPN code)!

And sorry, I forgot that a negative deltaEpsilon is a feature (it will not check at all if the data has changed since last query and always send the current value through). For testing that's OK, but in actual working code that might be less than optimal (unless there's a specific need for that, of course).

Cheers,
-Max

[mpaperno]

PS. Actually if your requested data type is a double but you try to convert the response to a float, the result should be zero (or rather a default-constructed float value, which ofc is 0.0). All conversion/casting of DataRequestRecord.data eventually ends up here in DataRequestRecord.tryConvert() where the data sizes are compared first:
https://github.com/mpaperno/WASimCommander/blob/next/src/WASimClient_CLI/Structs.h#L360