NI-VISA .NET ReadStatusByte freezes program

Hi All,

We decided to rewrite our huge calibration program to NI-VISA .NET platform. Before start I created simple Project which has only one Counter (Keysight 53230A). We want to use ServiceRequest event of MessageBasedSession object.

We use below code for creating counter object.

counter = (MessageBasedSession)ResourceManager.GetLocalManager().Open("GPIB0::17::INSTR");
counter.Timeout = GpibInterface.InfiniteTimeout;
counter.ServiceRequest += Counter_ServiceRequest;
counter.EnableEvent(MessageBasedSessionEventType.ServiceRequest, EventMechanism.Handler);
//this starts new measurement and trigger SRQ when finish
counter.Write("*CLS; *ESE 1; *SRE 32; INIT:IMM; *OPC"); 

When I run the program it reaches Service Request sub program and freezes at ReadStatusByte() line. If I omit this line, program reads data from counter and starts new measurements but ServiceRequest sub program does not call again.

private void Counter_ServiceRequest(object sender, MessageBasedSessionEventArgs e)
        {
            MessageBasedSession mb = sender as MessageBasedSession;
            if (mb != null)
            {
                //Program freezes this point
                //If omit this line, service request function does not run again 
                StatusByteFlags sb = mb.ReadStatusByte();   
                listBox1.Items.Add(mb.Query("FETCH?"));
                mb.Write("*CLS; INIT:IMM; *OPC"); //Restart measurement...

            }
        }

I tried AutoSerialPoll On or Off and results are same. I updated NI-VISA to 17.5 which is latest version.

Any idea?

Best regards,

Adem