GetBar/GetNumBars error

[MJMTrading]

Hey. I sometimes get an error when calling esignal.GetBar and esignal.GetNumBars in the OnBarsChanged event. Here's some of the code:

Private Sub esignal_OnBarsChanged(ByVal lHandle As Long)

Dim numBars As Long
Dim bar As IESignal.BarData

numBars = esignal.GetNumBars(lHandle)
If (numBars > 10) Then
numBars = 10
End If

For i = -1 * numBars + 1 To 0
bar = esignal.GetBar(lHandle, i)
...(Unrelated code)...
Next i

The last time the error happened, I received an error in the line "numBars = esignal.GetNumBars(lHandle)". The error message says "Automation error. System call failed." Also, the symbol corresponding to this handle was MAS.

Does anyone know what might be causing this?

[StarrM]

Hi,

Are you using Visual Studio 2005? This error is most commonly associated with that IDE. Unfortunately, we cannot support VS 2005 due to problems we have found with .NET 2.0.

We do occasionally see this error outside of that environment, and it often indicates resource issues. Here is a good overview on system calls:

http://en.wikipedia.org/wiki/System_call

[MJMTrading]

Thanks for the response. I am using Visual Basic 6.

The program causing the error monitors about 500 stocks. Could that be contributing to the error? Could you recommend any ways to prevent the error from occurring?

Thanks.

[StarrM]

I would say this is almost certainly the problem. The Desktop API can only efficiently handle about 50-100 symbols at a time, depending on your system resources.

[ddresser]

I have been tinkering with the eSignal Desktop API for a couple of weeks now, converting from the QFeed / QDP ocx which eSignal apparently is discontinuing. I now reliably can handle 200 symbols at a time, receiving 5 minute data using RequestHistory. The principle tricks are to put adequate pauses into the code at the right places to let eSignal do its thing and not to ask for more than one time scale for each symbol.