03-02-2009 02:39 PM
We have a BetaPI pressure Gauge with a RS232 output and a USB-9219 module to acquire data in one LabVIEW application. The 9219 is set up continuous samples at 5Hz, and the Gauge is set up at 1 sec update time. See the attached file for our starter code.
This system will be developed to test questionable pressure transducers against the calibrated Beta Gauge. Both devices will be supplied with oil and held under pressure at 10 different points, starting from zero. The 9219 will have inputs in various forms of analog data. We want to synchronize the data from both sources and read to one graph continuously and in real time and to send data to a report file once the user commands so. At the moment we are unsure how to get these two readings to synchronize. Writing to graphs and files has been achieved for each device independently, so this should not present much difficulty.
Let us know if more information is required.
03-02-2009 03:36 PM
You should set up your DAQ assistant to read 5 samples as once.
You should have the error out of the rendezvous go to the error in of the Express VI. As it is now, the Express VI's are in parallel and the rendezvous don't prevent them from running or trigger them to run.
03-03-2009 02:00 PM
When you say synchronize the data do you mean you would just like the timestamps of the two sets of data aligned on the graph used to display the data? If so, you will need to place both express vis within the same while loop. From there, you can either try simply merging the two output data signals and converting those to dynamic data prior to graphing and writing to a file. Otherwise, take a look at the align and resample express vi.