How can we access via DLL the data stream of P7889 count events ?
I am sorry, that is not possible. Via the DLL you can access directly only the histogram, not the data that is written into the list file. The list file is closed and reopened in some time intervals, so you can access it from other programs already during an acquisition. In the actual P7889 software "Replay" (evaluation of list files) is available. We have a special DLL that can directly access the hardware without the server, that we can send you if you have bought the standard DLL software, but it is not documented and requires a good knowledge of C programming.