Maximum stream to disk in a PXI8187 equipped with 2 PXI6289

[alemasi]

In a PXI system with a controller PXI-8187, 1Gb ram and flash ram 512 Mb equipped with 2 DAQ cards pxi6289 I have to acquire 8 channels at 100KS/s for a long time (1000s). I am using 4 channels for each of the two boards and I have synchronized the two boards in the VI. To store in continuous way the data on the PXI HD I am using the example relative to the continuous acquisition with new DAQMx drivers and storing the data in binary like I32. Even If I perform a single while where simply I read the data in block of 1000 samples(per channels) and write on file I cannot manage this sampling frequency, I mean the backlog increase and after a time determined by the buffer size I go in buffer overrun. What is the maximum stream to disk rate??? What are the advices to realize on this PXI configuration (the best on the market) a datalogger with the requirements specified?? I have seen that you suggest to use the hsdl VI but these work only with the last release of NIDAQ and not with the M series DAQ, doesn`t it???? I have tried to select reading like I16 but I receive an error since the converter is at 18 bits. What do you suggest me??? Have you performed benchmark with M cards and this system??? Up to now the maximum performances that I can have without overrunning is 4 channels at 92KS/s or 47KS/s on 8 channels

[Otis]

Which version of LabVIEW are you using?

How are you trying to write the file? Are you performing an open, write, and close in each loop?

Are you writing data in 18-bit format? Would you be willing to sacrifice some accuracy for speed?

Is this an RT application, or is it merely running on a controller that can do RT applications too?