Agilent Technologies N5183A MXG - Manual (Page 272)

262 Agilent N518xA, E8663B, E44x8C, and E82x7D Signal Generators Programming Guide
Creating and Downloading Waveform Files
Programming Examples
Visual Basic Programming Examples
Creating I/Q Data—Little Endian Order
On the documentation CD, this programming example’s name is “Create_IQData_vb.txt.”
This Visual Basic programming example, using Microsoft Visual Basic 6.0, uses little endian order
data, and performs the following functions:
• error checking
• I an Q integer array creation
• I an Q data interleaving
• byte swapping to convert to big endian order
• binary data file storing to a PC or workstation
Once the file is created, you can download the file to the signal generator using FTP (see “FTP
Procedures” on page 210 ).
'*************************************************************************************
' Program Name: Create_IQData
' Program Description: This program creates a sine and cosine wave using 200 I/Q data
' samples. Each I and Q value is represented by a 2 byte integer. The sample points are
' calculated, scaled using the AMPLITUDE constant of 32767, and then stored in an array
' named iq_data. The AMPLITUDE scaling allows for full range I/Q modulator DAC values.
' Data must be in 2's complemant, MSB/LSB big-endian format. If your PC uses LSB/MSB
' format, then the integer bytes must be swapped. This program converts the integer
' array values to hex data types and then swaps the byte positions before saving the
' data to the IQ_DataVB file.
'**************************************************************************************
Private Sub Create_IQData()
Dim index As Integer
Dim AMPLITUDE As Integer
Dim pi As Double
Dim loByte As Byte
Dim hiByte As Byte
Dim loHex As String
Dim hiHex As String
Dim strSrc As String
Dim numPoints As Integer
Dim FileHandle As Integer
Dim data As Byte
Dim iq_data() As Byte
Dim strFilename As String
strFilename = "C:\IQ_DataVB"
Const SAMPLES = 200 ' Number of sample PAIRS of I and Q integers for the waveform