Acquiring waveform using DSOZ204A, VC++ and Visa library

[Kentish]

Hello everyone,

I'm actually trying to acquire a waveform of my infiniium DSOZ204A from Keysight.

I use the Visa Library 32bit and VC++ 2008 express edition.

I've copied, pasted and modified the code given by Keysight in their documentation. After a few bug correction the communication was established and I was able to modify some attributes.

But, when the acquiring process comes everything goes wrong. I send the command :WAVeform:DATA? to access the buffer where the data is and when it comes to the reading part I have an error : "VISA error: a format specifier in the format string is not valid". Then, a security implemented by Keysight in the code tell me that the IEEE block buffer is full.

Does anyone know where the problem is?

I thought the problem could come from the runtime Library, but obviously not. Maybe a pointer is not well defined...

Please find the code:

/*
 * Keysight VISA Example in C
 * ------------------------------------------------------------------
 * This program illustrates a few commonly-used programming
 * features of your Keysight Infiniium Series oscilloscope.
 */

#include <stdio.h>            /* For printf(). */
#include <string.h>           /* For strcpy(), strcat(). */
#include <time.h>             /* For clock(). */
#include <visa.h>             /* Keysight VISA routines. */

#define VISA_ADDRESS "TCPIP0::141.121.237.226::hislip0::INSTR"
#define IEEEBLOCK_SPACE 5000000

/* Function prototypes */
void initialize(void);          /* Initialize to known state. */
void capture(void);             /* Capture the waveform. */
void analyze(void);             /* Analyze the captured waveform. */

void do_command(char *command);        /* Send command. */
int do_command_ieeeblock(char *command); /* Command w/IEEE block. */
void do_query_string(char *query);     /* Query for string. */
void do_query_number(char *query);     /* Query for number. */
void do_query_numbers(char *query);     /* Query for numbers. */
int do_query_ieeeblock(char *query);   /* Query for IEEE byte block. */
int do_query_ieeeblock_words(char *query);   /* Query for word block. */
void check_instrument_errors();        /* Check for inst errors. */
void error_handler();                  /* VISA error handler. */

/* Global variables */
ViSession defaultRM, vi;        /* Device session ID. */
ViStatus err;                   /* VISA function return value. */
char str_result[256] = {0};     /* Result from do_query_string(). */
double num_result;              /* Result from do_query_number(). */
unsigned char ieeeblock_data[IEEEBLOCK_SPACE];   /* Result from
                                   do_query_ieeeblock(). */
signed short ieeeblock_data_words[IEEEBLOCK_SPACE];   /* Result from
                                   do_query_ieeeblock_words(). */
double dbl_results[10];         /* Result from do_query_numbers(). */

/* Main Program
 * --------------------------------------------------------------- */
void main(void)
{
  /* Open the default resource manager session. */
  err = viOpenDefaultRM(&defaultRM);
  if (err != VI_SUCCESS) error_handler();

  /* Open the session using the oscilloscope's VISA address. */
  err = viOpen(defaultRM, VISA_ADDRESS, VI_NULL, VI_NULL, &vi);
  if (err != VI_SUCCESS) error_handler();

  /* Set the I/O timeout to fifteen seconds. */
  err = viSetAttribute(vi, VI_ATTR_TMO_VALUE, 15000);
  if (err != VI_SUCCESS) error_handler();

  /* Clear the interface. */
  err = viClear(vi);
  if (err != VI_SUCCESS) error_handler();

  /* Initialize - start from a known state. */
  initialize();

  /* Capture data. */
  capture();

  /* Analyze the captured waveform. */
  analyze();

  /* Close the vi session and the resource manager session. */
  viClose(vi);
  viClose(defaultRM);
}

/* Initialize the oscilloscope to a known state.
 * --------------------------------------------------------------- */
void initialize (void)
{
  /* Clear status. */
  do_command("*CLS");

  /* Get and display the device's *IDN? string. */
  do_query_string("*IDN?");
  printf("Oscilloscope *IDN? string: %s\n", str_result);

  /* Load the default setup. */
  do_command("*RST");
}

/* Capture the waveform.
 * --------------------------------------------------------------- */
void capture (void)
{
  int num_values;
  FILE *fp;

  /* Set probe attenuation factor. */
  do_command(":CHANnel1:PROBe 1.0");
  do_query_string(":CHANnel1:PROBe?");
  printf("Channel 1 probe attenuation factor: %s\n", str_result);

  /* Use auto-scale to automatically configure oscilloscope. */
  do_command(":AUToscale");

  /* Set trigger mode. */
  do_command(":TRIGger:MODE EDGE");
  do_query_string(":TRIGger:MODE?");
  printf("Trigger mode: %s\n", str_result);

  /* Set EDGE trigger parameters. */
  do_command(":TRIGger:EDGE:SOURCe CHANnel1");
  do_query_string(":TRIGger:EDGE:SOURce?");
  printf("Trigger edge source: %s\n", str_result);

  do_command(":TRIGger:LEVel CHANnel1,-2E-3");
  do_query_string(":TRIGger:LEVel? CHANnel1");
  printf("Trigger level, channel 1: %s\n", str_result);

  do_command(":TRIGger:EDGE:SLOPe POSitive");
  do_query_string(":TRIGger:EDGE:SLOPe?");
  printf("Trigger edge slope: %s\n", str_result);

  /* Save oscilloscope setup. */

  /* Read system setup. */
  num_values = do_query_ieeeblock(":SYSTem:SETup?");
  printf("Read setup string query (%d bytes).\n", num_values);

  /* Write setup string to file. */
  fp = fopen ("c:\\scope\\config\\setup.stp", "wb");
  num_values = fwrite(ieeeblock_data, sizeof(unsigned char), num_values,
    fp);
  fclose (fp);
  printf("Wrote setup string (%d bytes) to ", num_values);
  printf("c:\\scope\\config\\setup.stp.\n");

  /* Change settings with individual commands:
  
  /* Set vertical scale and offset. */
  do_command(":CHANnel1:SCALe 0.1");
  do_query_string(":CHANnel1:SCALe?");
  printf("Channel 1 vertical scale: %s\n", str_result);

  do_command(":CHANnel1:OFFSet 0.0");
  do_query_string(":CHANnel1:OFFSet?");
  printf("Channel 1 offset: %s\n", str_result);

  /* Set horizontal scale and offset. */
  do_command(":TIMebase:SCALe 0.0002");
  do_query_string(":TIMebase:SCALe?");
  printf("Timebase scale: %s\n", str_result);

  do_command(":TIMebase:POSition 0.0");
  do_query_string(":TIMebase:POSition?");
  printf("Timebase position: %s\n", str_result);

  /* Set the acquisition mode. */
  do_command(":ACQuire:MODE RTIMe");
  do_query_string(":ACQuire:MODE?");
  printf("Acquire mode: %s\n", str_result);

  /* Or, set up by loading a previously saved setup. */

  /* Read setup string from file. */
  fp = fopen ("c:\\scope\\config\\setup.stp", "rb");
  num_values = fread (ieeeblock_data, sizeof(unsigned char),
    IEEEBLOCK_SPACE, fp);
  fclose (fp);
  printf("Read setup string (%d bytes) from file ", num_values);
  printf("c:\\scope\\config\\setup.stp.\n");

  /* Restore setup string. */
  num_values = do_command_ieeeblock(":SYSTem:SETup", num_values);
  printf("Restored setup string (%d bytes).\n", num_values);

  /* Set the desired number of waveform points,
   * and capture an acquisition. */
  do_command(":ACQuire:POINts 32000");
  do_command(":DIGitize");
}

/* Analyze the captured waveform.
 * --------------------------------------------------------------- */
void analyze (void)
{
  double wav_format;
  double acq_type;
  double wav_points;
  double avg_count;
  double x_increment;
  double x_origin;
  double y_increment;
  double y_origin;

  FILE *fp;
  int num_values;   /* Number of bytes returned from instrument. */
  int i;

  /* Make measurements.
   * ------------------------------------------------------------- */
  do_command(":MEASure:SOURce CHANnel1");
  do_query_string(":MEASure:SOURce?");
  printf("Measure source: %s\n", str_result);

  do_command(":MEASure:FREQuency");
  do_query_number(":MEASure:FREQuency?");
  printf("Frequency: %.4f kHz\n", num_result / 1000);

  do_command(":MEASure:VAMPlitude");
  do_query_number(":MEASure:VAMPlitude?");
  printf("Vertical amplitude: %.2f V\n", num_result);

  /* Download the screen image.
   * ------------------------------------------------------------- */

  /* Read screen image. */
  num_values = do_query_ieeeblock(":DISPlay:DATA? PNG");
  printf("Screen image bytes: %d\n", num_values);

  /* Write screen image bytes to file. */
  fp = fopen ("c:\\scope\\data\\screen.png", "wb");
  num_values = fwrite(ieeeblock_data, sizeof(unsigned char), num_values,
    fp);
  fclose (fp);
  printf("Wrote screen image (%d bytes) to ", num_values);
  printf("c:\\scope\\data\\screen.bmp.\n");

  /* Download waveform data.
   * ------------------------------------------------------------- */

  /* Get the waveform type. */
  do_query_string(":WAVeform:TYPE?");
  printf("Waveform type: %s\n", str_result);

  /* Get the number of waveform points. */
  do_query_string(":WAVeform:POINts?");
  printf("Waveform points: %s\n", str_result);

  /* Set the waveform source. */
  do_command(":WAVeform:SOURce CHANnel1");
  do_query_string(":WAVeform:SOURce?");
  printf("Waveform source: %s\n", str_result);

  /* Choose the format of the data returned: */
  do_command(":WAVeform:FORMat WORD");
  do_query_string(":WAVeform:FORMat?");
  printf("Waveform format: %s\n", str_result);

  /* Display the waveform settings: */
  do_query_number(":WAVeform:XINCrement?");
  x_increment = num_result;
  printf("Waveform X increment: %e\n", x_increment);

  do_query_number(":WAVeform:XORigin?");
  x_origin = num_result;
  printf("Waveform X origin: %e\n", x_origin);

  do_query_number(":WAVeform:YINCrement?");
  y_increment = num_result;
  printf("Waveform Y increment: %e\n", y_increment);

  do_query_number(":WAVeform:YORigin?");
  y_origin = num_result;
  printf("Waveform Y origin: %e\n", y_origin);

  /* Read waveform data. */
  num_values = do_query_ieeeblock_words(":WAVeform:DATA?");
  printf("Number of data values: %d\n", num_values);

  /* Open file for output. */
  fp = fopen("c:\\scope\\data\\waveform_data.csv", "wb");

  /* Output waveform data in CSV format. */
  for (i = 0; i < num_values - 1; i++)
  {
    /* Write time value, voltage value. */
    fprintf(fp, "%9f, %6f\n",
      x_origin + ((float)i * x_increment),
      ((float)ieeeblock_data_words[i] * y_increment) + y_origin);
  }

  /* Close output file. */
   fclose(fp);
   printf("Waveform format WORD data written to ");
   printf("c:\\scope\\data\\waveform_data.csv.\n");
}

/* Send a command to the instrument.
 * --------------------------------------------------------------- */
void do_command(command)
char *command;
{
  char message[80];

  strcpy(message, command);
  strcat(message, "\n");
  err = viPrintf(vi, message);
  if (err != VI_SUCCESS) error_handler();

  check_instrument_errors();
}

/* Command with IEEE definite-length block.
 * --------------------------------------------------------------- */
int do_command_ieeeblock(command, num_bytes)
char *command;
int num_bytes;
{
  char message[80];
  int data_length;

  strcpy(message, command);
  strcat(message, " #8%08d");
  err = viPrintf(vi, message, num_bytes);
  if (err != VI_SUCCESS) error_handler();

  err = viBufWrite(vi, ieeeblock_data, num_bytes, &data_length);
  if (err != VI_SUCCESS) error_handler();

  check_instrument_errors();

  return(data_length);
}

/* Query for a string result.
 * --------------------------------------------------------------- */
void do_query_string(query)
char *query;
{
  char message[80];

  strcpy(message, query);
  strcat(message, "\n");

  err = viPrintf(vi, message);
  if (err != VI_SUCCESS) error_handler();

  err = viScanf(vi, "%t", str_result);
  if (err != VI_SUCCESS) error_handler();

  check_instrument_errors();
}

/* Query for a number result.
 * --------------------------------------------------------------- */
void do_query_number(query)
char *query;
{
  char message[80];

  strcpy(message, query);
  strcat(message, "\n");

  err = viPrintf(vi, message);
  if (err != VI_SUCCESS) error_handler();

  err = viScanf(vi, "%lf", &num_result);
  if (err != VI_SUCCESS) error_handler();

  check_instrument_errors();
}

/* Query for numbers result.
 * --------------------------------------------------------------- */
void do_query_numbers(query)
char *query;
{
  char message[80];

  strcpy(message, query);
  strcat(message, "\n");

  err = viPrintf(vi, message);
  if (err != VI_SUCCESS) error_handler();

  err = viScanf(vi, "%,10lf\n", dbl_results);
  if (err != VI_SUCCESS) error_handler();

  check_instrument_errors();
}

/* Query for an IEEE definite-length byte block result.
 * --------------------------------------------------------------- */
int do_query_ieeeblock(query)
char *query;
{
  char message[80];
  int data_length;

  strcpy(message, query);
  strcat(message, "\n");
  err = viPrintf(vi, message);
  if (err != VI_SUCCESS) error_handler();

  data_length = IEEEBLOCK_SPACE;
  err = viScanf(vi, "%#b\n", &data_length, ieeeblock_data);
  if (err != VI_SUCCESS) error_handler();

  if (data_length == IEEEBLOCK_SPACE )
  {
    printf("IEEE block buffer full: ");
    printf("May not have received all data.\n");
  }

  check_instrument_errors();

  return(data_length);
}

/* Query for an IEEE definite-length word block result.
 * --------------------------------------------------------------- */
int do_query_ieeeblock_words(query)
char *query;
{
  char message[80];
  int data_length;

  strcpy(message, query);
  strcat(message, "\n");
  err = viPrintf(vi, message);
  if (err != VI_SUCCESS) error_handler();

  data_length = IEEEBLOCK_SPACE;
  err = viScanf(vi, "%#hb\n", &data_length, ieeeblock_data_words);
  if (err != VI_SUCCESS) error_handler();

  if (data_length == IEEEBLOCK_SPACE )
  {
    printf("IEEE block buffer full: ");
    printf("May not have received all data.\n");
  }

  check_instrument_errors();

  return(data_length);
}

/* Check for instrument errors.
 * --------------------------------------------------------------- */
void check_instrument_errors()
{
  char str_err_val[256] = {0};
  char str_out[800] = "";

  err = viQueryf(vi, ":SYSTem:ERRor? STRing\n", "%t", str_err_val);
  if (err != VI_SUCCESS) error_handler();
  while(strncmp(str_err_val, "0,", 2) != 0 )
  {
    strcat(str_out, ", ");
    strcat(str_out, str_err_val);
    err = viQueryf(vi, ":SYSTem:ERRor? STRing\n", "%t", str_err_val);
    if (err != VI_SUCCESS) error_handler();
  }

  if (strcmp(str_out, "") != 0)
  {
    printf("INST Error%s\n", str_out);
    err = viFlush(vi, VI_READ_BUF);
    if (err != VI_SUCCESS) error_handler();
    err = viFlush(vi, VI_WRITE_BUF);
    if (err != VI_SUCCESS) error_handler();
  }
}

/* Handle VISA errors.
 * --------------------------------------------------------------- */
void error_handler()
{
  char err_msg[1024] = {0};

  viStatusDesc(vi, err, err_msg);
  printf("VISA Error: %s\n", err_msg);
  if (err < VI_SUCCESS)
  {
    exit(1);
  }
}