Pendulum CNT-91 - Page 58

// Fetch the measurement results as it goes.
Count = 0;
while (true)
{
CheckUserCancel();
// The 'max' parameter means fetch as many samples as is
// currently available for fetching (but no more than
// the upper limit, which by default is 10000).
if (WriteDev("fetc:arr? max") != VI_SUCCESS) Quit();
if (ReadDev(Buffer, BUFSIZE, &ReadLength) != VI_SUCCESS)
Quit();
Buffer[ReadLength] = 0; // Null terminate.
pBuf = Buffer;
// Check for fetc:arr? max 'no data' marker.
char *p = pBuf;
if (*p++ == '#' && *p++ == '1' && *p == '0') {
// There's no data available at the moment. Wait a
// bit with the next fetch attempt in order to avoid
// swamping the instrument with useless operations
// which could actually starve the measurement
// handling in the instrument.
Sleep(20);
continue;
}
// Scan FORMat PACKed header.
if (*pBuf++ != '#') {
printf("Failed to scan packed header start\n");
WriteDev("abort");
Quit();
}
Digits = *pBuf++ - '0';
if (Digits<1||Digits > 9) {
printf("Failed to scan packed header size\n");
WriteDev("abort");
Quit();
}
int Size = 0;
for (i=0; i<Digits; i++) {
Size = 10 * Size + (int)(*pBuf++ - '0');
}
// With format packed and format:tinf on each sample is
// a double format measurement value and a 64 bit
// integer timestamp (in ps), for a total of
// 16 bytes / sample.
Samples = Size / 16;
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4-22 Error Code