The problem is to monitor two experimental parameters

Question

The problem is to monitor two experimental parameters (pressure and temperature) using USB -6008. These parameters are converted to voltage by proper sensors.
I use the following sequence of commans:
DAQmxBaseCreateTask("T",&taskHandle);
DAQmxBaseCreateAIVoltageChan(taskHandle,"Dev1/ai0","",DAQmx_Val_Diff,-10,10,DAQmx_Val_Volts,NULL);
DAQmxBaseCreateAIVoltageChan(taskHandle,"Dev1/ai1","",DAQmx_Val_Diff,-1,1,DAQmx_Val_Volts,NULL);
DAQmxBaseStartTask(taskHandle);
Then I read the results every 200 msec. To do this I put into the Timer event handler next code:
{ DAQmxBaseReadAnalogF64(taskHandle,1,timeout,0,data,2,&pointsRead,NULL);
data[0] I convert to pressure;
data[1] I convert to temperature;
The program works, but I am not satisfied because of noise. The origin of the noise is electric interference of power network. I know that the best way to reduce electrical interference is to integrate a signal over period of the power network (20 msec in Russia). All high sensitivity digital voltmeters do this integration. The idea is to make, for example, 40 measurements with SampleRate=2000 , ( 0.5 msec * 40 = 20 msec) instead of single measurement. Then calculate the sum of pressure readouts and the sum of temperature readouts. This procedure should be repeated every 200 msec using the Timer event handler.
Therefore I added before DAQmxBaseStartTask(taskHandle);
DAQmxBaseCfgSampClkTiming (taskHandle, source, sampleRate, DAQmx_Val_Rising, DAQmx_Val_FiniteSamps, 40);
and modified Timer event handler:
{ DAQmxBaseReadAnalogF64(taskHandle,40,timeout,0,data,80,&pointsRead,NULL);
data[0] … data[39] I convert to pressure;
data[40] … data[79] I convert to temperature;
Testing of the program showed: the program can make only one cycle of measurement. All times I call the DAQmxBaseReadAnalogF64 the results were the same. It looks like USB-6008 make one cycle of measurement (probably at DAQmxBaseStartTask) and puts the results to the buffer. And the DAQmxBaseReadAnalogF64 just read the buffer but can not initiate new measurements.
How the program can initiate new cycle of measurements? Could anybody to help me?

Answer 1

Dear Micaela,
Thank you for advice. I will change driver  to the DAQmx . But it will take time to download 460 M.
Therefore I continued with the old driver.           
I changed DAQmxBaseCfgSampClkTiming to DAQmx_Val_ContSamps and immediately faced with  another problem.   The device began to acquire data continuously, and when I call DAQmxBaseReadAnalogF64 in the timer handler, I got the date that does not correspond to the current time. The data corresponds to the experimental parameters which were 5 minutes ago. I was very surprised until I realized that this huge delay exits!
To fix this problem I tried to add DAQmxBaseStartTask and DAQmxBaseStopTask  to the timer handler.
     DAQmxBaseStartTask(taskHandle);
     DAQmxBaseReadAnalogF64(taskHandle,40,timeout,0,data,80,&pointsRead,NULL);
     DAQmxBaseStopTask(taskHandle);
    data[0] … data[39] I convert to pressure;
     data[40] … data[79] I convert to temperature;
The program did not work. Even did not respond to any action.