I have been looking for some help on this for a bit, but can't seem to find the answers. Basically I need to measure RPM and Pressure using NIDAQmx, I can get read the voltage ch from transdeucer fine. However, I need to use the 20 MHZ CLK as the source, and I want to use The counters at PFI7 and PFI4 as triggers Gates. Encoder counter is hooked up to PFI7 and PFI4. PFI7 used to Gate the src , and PFI4 used for once per revolution. Basically, I am looking for time reference (time Value) from the src clk when I Gate it. I got this code from one of the NI support guys , but it's giving strange numbers in the billions, I am not sure if its connected correctly?
DAQmxErrChk (DAQmxCreateCICountEdgesCha(taskHandle,"Dev1/Ctr0","",DAQmx_Val_Rising,0,DAQmx_Val_CountUp));DAQmxErrChk (DAQmxSetCICountEdgesTerm(taskHandle,"Dev1/Ctr0","/Dev1/20MHzTimebase"));
DAQmxErrChk (DAQmxCfgSampClkTiming(taskHandle,"/Dev1/PFI7",1000.0,DAQmx_Val_Rising,DAQmx_Val_ContSamps,1000));
DAQmxErrChk (DAQmxReadCounterU32(taskHandle,100000,10.0,data,1000,&read,NULL));
With this code, sometimes I get "Data is overwritten", but when I do get readings, I am getting crazy numbers, I thought I would be reading time values less than (2^24 -1). ? Does the code make sense, or what am I doing wrong?
Thanks a lot for your help
