Re: EpicsSharp issues

[Alain Bertrand <alain.bertrand@psi.ch>]

Hi Christopher,

You should be able to work with floats indeed. However it could be that 
I didn't tested it correctly. I will do some trials next week and let 
you know. In the mean time, can you please try to grab it as double[] 
instead of float[] and see if it works?
Sincerely,

Alain Bertrand

On 11/22/2013 4:10 PM, Christopher J. Pendleton wrote:
> Hello. Let me start by saying that I started using EPICS to interface to our
> company's devices (http://ptcusa.com/) earlier this year and it has been a
> pleasure to work with. You guys are doing great work and I hope I can
> contribute to the cause.
>
> One of my colleagues is a big fan of C#, so I pointed him to the EpicsSharp
> library. I started using it to help him sort through some issues he was
> having. The major one I am seeing is with float arrays (arrays in general?)
> while using the MonitorChanged event.
>
> Details:
>
> I have a channel access server running, serving up a float array PV. Both
> Python (PyEpics) and LabVIEW (CA Lab) client interfaces see this PV and
> recognize it as a float array. No problems here. When I use EpicsSharp, I
> can get the float array by using the synchronous call Get<float[]>() on the
> channel object. Also no problems here. I see unexpected behavior when I use
> the MonitorChanged event. My code:
>
> ///
>      static class Program
>      {
>          [STAThread]
>          static void Main()
>          {
>              EpicsClient client = new EpicsClient();
>              EpicsChannel<float[]> record =
> client.CreateChannel<float[]>("r_I128_channels_test");
>              record.MonitorChanged += new
> EpicsDelegate<float[]>(record_MonitorChanged);
>              Console.ReadKey();
>          }
>
>          static void record_MonitorChanged(EpicsChannel<float[]> sender,
> float[] newValue)
>          {
>              Console.WriteLine("Help!");
>          }
>      }
> ///
>
> I would expect to see an event fire into my handler, but I don't. What I do
> see is an exception in my console window:
>
> ///
> System.Collections.Generic.KeyNotFoundException: The given key was not
> present i
> n the dictionary.
>     at System.Collections.Generic.Dictionary`2.get_Item(TKey key)
>     at PSI.EpicsClient2.EpicsChannel`1.<Disconnect>b__3(EpicsChannel action)
> in D
> :\Projects\epicsC#\client\EpicsGenericChannel.cs:line 99
> ///
>
> I dug into the client library code and found that the exception was
> happening in EpicsGenericChannel.cs, line 99.
>
> //
> p.DataType = (ushort) TypeHandling.Lookup[typeof (TType)];
> //
>
> typeof (TType) evaluates to Single[], which isn't in TypeHandling
> Dictionary, so an exception is thrown.
>
> Do you expect this behavior? Is there a problem in my client program code? I
> found another example on techtalk by Alain Bertrand
> (http://www.aps.anl.gov/epics/tech-talk/2011/msg01584.php) that shows almost
> the same code with an int[], so I am a little lost. Thanks in advance for
> your help!
>
> Regards,
> Chris
>
> Christopher J. Pendleton
> Director, Software Development
> Pyramid Technical Consultants, Inc.
> Office: +1 781-402-1700 x114
> Cell: +1 781-249-3031