using System;

using System.Text;

using System.IO;

using NationalInstruments.VisaNS;

using System.Threading;

 

namespace Example5

{

class Program

{

static void Main(string[] args)

{

//VXI-11 Connection string

string sAddress = "TCPIP0::10.0.1.196::INSTR";

 

//The VNA uses a message based session

MessageBasedSession mbSession = null;

//But we'll just open a generic Session first

Session mySession = null;

 

double[] responseArray = null;

 

try

{

//open a Session to the VNA

mySession = ResourceManager.GetLocalManager().Open(sAddress);

//cast this to a message based session

mbSession = (MessageBasedSession)mySession;

 

//Timeout to 1 second (1000 ms)

mbSession.Timeout = 1000;

mbSession.TerminationCharacter = 0x0a;

mbSession.TerminationCharacterEnabled = false;

mbSession.SendEndEnabled = true;

 

//We'll limit the number of data points to keep buffer small

mbSession.DefaultBufferSize = 5000;

testClear(mbSession);

 

//Set the Language to NATIVE

//This code group sets the sweep to 8 points,

//then makes trace2 active, sets to Mag-Phase, does a trigger sweep,

//and waits for sweep to finish.

//Then it sets output format to 64 bit binary and

//least significant bit first (little endian) and

//asks for Final Data.

mbSession.Write("LANG NATIVE\n");

mbSession.Write("CH2;MPH;\n");

mbSession.Write(":SENSE:SWEEP:POINTS 8\n");

mbSession.Write("TRS;WFS;HLD\n");

mbSession.Write("LSB;FMB;OFD\n");

responseArray = testStatus_ReadArbBinaryDouble(mbSession);

//responseArray[] will hold the 16 readings from the VNA.

//They will be mag1, phase1, mag2, phase2, etc.

//Send results to a file

StreamWriter output = new StreamWriter("OFD.txt");

output.WriteLine("Native Results (Mag-Phase)");

foreach (double d in responseArray)

output.WriteLine(d);

output.Close();

mbSession.Write("RTL\n");

mbSession.Dispose();

}

catch (VisaException v_exp)

{

Console.WriteLine("Visa caught an error!!");

Console.WriteLine(v_exp.Message);

}

 

catch (Exception exp)

{

Console.WriteLine("Something didn't work!!");

Console.WriteLine(exp.Message);

}

 

}

 

private static double[] testStatus_ReadArbBinaryDouble(MessageBasedSession mbSession)

{

//These are the bits to check

int b2 = 4, //Error Queue is not empty

b4 = 16; //MAV = Message Available

byte[] responsebytes = null;

double[] replybytes = null;

string errorString = null;

 

//Read the Status Byte of Service Request Status Register

StatusByteFlags sb = mbSession.ReadStatusByte();

 

while (((int)sb & (b2 + b4)) == 0)

{

Thread.Sleep(10);

sb = mbSession.ReadStatusByte();

}

if (((int)sb & b2) != 0)

{

errorString = mbSession.Query("OGE\n");

Console.WriteLine("Error Queue: " + errorString);

}

else if (((int)sb & b4) != 0)

{

//Here we use the ReadByteArray() function to read the

//binary data into a byte array.

//Then we convert the bytes to doubles.

responsebytes = mbSession.ReadByteArray();

replybytes = arbToDouble(responsebytes);

 

}

mbSession.Write("*CLS\n");

return replybytes;

}

 

private static void testClear(MessageBasedSession mbSession)

{

mbSession.Write("*CLS\n");

}

 

//Here we convert Arb Block Binary Data to a double array

//This function reads the arbitrary block header and then converts

//the byte array into a double array. Every 8 bytes is converted to

//a double. We use a MemoryStream and BinaryReader to do the conversion.

private static double[] arbToDouble(byte[] responseBytes)

{

int i = 0;

double[] dReturn = null;

 

//Arbitrary Block should start with a #

if (responseBytes[i++] == '#')

{

//Header is ASCII, get 2nd byte and convert to int

string sCount = ASCIIEncoding.ASCII.GetString(responseBytes, i++, 1);

int count1 = int.Parse(sCount);

//now read the bytecount string and convert to int

string sBytes = ASCIIEncoding.ASCII.GetString(responseBytes, i, count1);

int count2 = int.Parse(sBytes);

//the number of doubles is the #bytes/sizeof(double)

int dataCount = count2 / sizeof(double);

//resize the response array

dReturn = new double[dataCount];

//set the index of the start of the data

i += count1;

 

//There are many ways to convert a byte array to a double array

MemoryStream stream = new MemoryStream(responseBytes, i, count2);

//BinaryReader reads this data type in little-endian format

//So we must use the LSB mnemonic when acquiring the data

BinaryReader reader = new BinaryReader(stream);

for (int ii = 0; ii < dataCount; ii++)

{

dReturn[ii] = reader.ReadDouble();

}

}

return dReturn;

}

}

}