Keysight Technologies X-Series, Programming Manual

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Keysight CXG, EXG, and MXG X-Series Signal Generators Programming Guide 353
Creating and Downloading User–Data Files
Pattern RAM (PRAM) Data Downloads
following the command execution, the program downloads the binary file to
the signal generator. This is shown in the following section, “Command Syntax
in a Program Routine”
Command Syntax in a Program Routine
This section demonstrates the use of the download SPCI command within the
confines of a C++ program routine. The following code sends the SCPI
command and downloads a 240 byte PRAM file to the signal generator’s
WFM1 (waveform) memory catalog. This program assumes that there is a char
array, databuffer , that contains the 240 bytes of PRAM data and that the
variable numbytes stores the length of the array.
Line Code—Download PRAM File Data
1
2
3
4
5
6
7
8
9
int bytesToSend;
bytesToSend = numbytes;
char s[4];
char cmd[200];
sprintf(s, "%d", bytesToSend);
sprintf(cmd, ":MEM:DATA:PRAM:FILE:BLOCk \"FILE1\", #%d%d",
strlen(s),bytesToSend);
iwrite(id, cmd, strlen(cmd), 0, 0);
iwrite(id, databuffer, bytesToSend, 0, 0);
iwrite(id, "\n", 1, 1, 0);
Line Code Description—Download PRAM File Data
1 Define an integer variable ( bytesToSend ) to store the number of bytes to send to the signal
generator.
2 Store the total number of PRAM bytes in the integer variable defined in line 1. numbytes contains
the length of the databuffer array referenced in line 8.
3 Create a string large enough to hold the bytesToSend value as characters plus a null character
value. In this code, string s is set to 4 bytes (3 characters for the bytesToSend value and one null
character—one character equals one byte).
4 Create a string and set its length ( cmd [200] ) to hold the SCPI command syntax and parameters. In
this code, we define the string length as 200 bytes (200 characters).
5 Store the value of bytesToSend in string s . For this example, bytesToSend = 240; s = ”240”
6 Store the SCPI command syntax and parameters in the string cmd . The SCPI command prepares
the signal generator to accept the data.
— sprintf() is a standard function in C++, which writes string data to a string
variable.
— strlen() is a standard function in C++, which returns length of a string.
— bytesToSend = 240, then s = “240” plus the null character, strlen(s) = 4, so
cmd = :MEM:DATA:PRAM:FILE:BLOCk ”FILE1\” #3240.