This file format is frequently used in field tests with Pacific Data recorders.
These files consist of a header block followed by data representing measured voltage. The header structure used in these files is defined below:
typedef struct tagHEADER {
char tag[8]; /* Channel name */
char desc[20]; /* Channel description */
char loct[20]; /* Gage location */
char units[14]; /* Engineering units */
char datetime[19]; /* Time and date channel
was saved */
char sernum[13]; /* Gage serial number */
char model[15]; /* Gage model */
char range[8]; /* Gage range */
char cable[5]; /* Instrumentation cable
number */
char testname[40]; /* Test name */
char testloc[20]; /* Test location */
char operator[20]; /* Instrumentation technician */
short channel; /* TDR number */
short caltype; /* Automatic (1) or
Simulated (2) Cal */
short trigenable; /* Internal trigger enabled=-1,
disable=0 */
short numpre; /* # of pretrigger segments */
short numpost; /* # of posttrigger segments */
short rate[15]; /* Rate in microseconds for
each segment */
short memsize; /* TDR memory size in KB */
float val1; /* Cal baseline in engineering
units */
float val2; /* Cal step in engineering
units */
float svolts1; /* Cal baseline in volts */
float svolts2; /* Cal step in volts */
float poly1; /* Conversion polynomial
offset */
float poly2; /* Conversion polynomial scale
factor */
float triglevel; /* Trigger level in
millivolts */
float ca; /* Gage CA */
float re; /* Gage RE */
float rx; /* Gage RX */
float rg; /* Gage RG */
float tworl; /* Cable line resistance */
float pred; /* Engineering prediction */
float rc; /* Actual cal resistor used */
double strttotrig; /* Start to trigger time */
short prate;
float gain;
float sensitivity;
char projectname[40];
char dummy[1690];
} HEADER;
Files produced using this format are always 264,192 bytes in size. The header block (shown above) begins at the start of the file, and is followed (at offset 2048) by 16 segments of 8192 2-byte integers representing voltages (the last block of 16384 bytes is not used by DPlot). The time step for each segment (in microseconds) is taken from the rate member of the header.
Raw voltages are translated to engineering units by:
Volts = float(RawData)/32768.;
Y = Header.poly2 * Volts + Header.poly1;
Page url:
https://www.dplot.com/help/index.htm?wesnewformat.htm