@masterwho wrote:
Thank you very much for your reply. I tried to use time stamp to control the creation of the files. However, it seems that the wait function isn't stable enough, it didn't sample as expected. For example, I set the wait function to wait for 10ms, but it delays for about 12ms. It's really weird! Do you know how to fix it?
Thanks a lot!
The Windows operating system has overhead that Labview cannot control. So it is possible that setting a wait for 10ms may result in a longer execution time. There is nothing that can be done about that. However, there is a Timed Loop function within Labview that will casue the code to be executed in the exact time specified (well, almost exact). So if you are worred about timing that much, use the timed loop and set it for 1 minute (60 seconds or 60000ms). Put all the code inside the timed loop but delete the wait function.
If you read my last sentence below my diagram, you would have seen that I made a mistake with the wait time. It should be set to 60000 ms. This is one minute. With this modification, the code will check every minute for the minutes part of the time string to be 00. It isn't time critical. It can check every 60000ms or every 60012 ms, it will still catch the beginning of the hour.
If the wait is a lot more than 60000ms, there could be a scenario where the code runs at 5:59:59.999pm and the wait is a little more than one minute and the next time it runs will be at 6:01:00.000001, then it will miss the beginning of the hour. A timed loop would fix that for sure. Also, code can be written to check the hour portion of the time string and store it into a shift register. Continue to check the time string every minute. When the hour is no longer equal to the stored hour, then you create a new file. This method will guarantee a new file every hour even though the wait time may be slightly more than one minute.
