I have an application running continuous acquisition like example: ..\MeasurementStudioVS2003\DotNET\Examples\DAQmx\Analog In\Measure Voltage\ContAcqVoltageSamples_IntClk\Vb\ContAcqVoltageSamples_IntClk.sln It was working ok, however the pc was migrated to a different windows installation, now every time I start acquisition the callback for reading data is being called many times, it seems the USB-6009 stored data after stopping the acquisition on previous cycle. The pc was running WinXp but the one supplied by the vendor, the new installation it was took from a corporate image being WinXp professional. Tnx.
