lizimunro

I am still getting used to Labview and wondered if someone could give me any advice on the best way to store test setting values for each element of the listbox. I have two listboxes. 1) That displays three possible tests and 2) That allows any combination of the tests from listbox 1 to be selected via two navigation buttons. Once the user has selected the tests and they appear in the 'selected tests' listobox. I would then like to store values of flow rate and hours for each test so that when the user clicks on the test in the listbox - the corresponding values for that test appear in the flow rate and hours controls. I am not sure whether this needs to be done via a listbox event or a change value event and as I am a novice at building arrays I would appreciate any advice. Many Thanks, Liz

Thanks very much - I appreciate your help and it is extremely useful for me :-)

Thanks for all the advice, it is very useful as I am new to coding in Labview (as you can tell!) and the housekeeping aspect is not really covered in the books. I have kind of solved my problem. I have changed a few functions but I put a delay of 5000 ms in as well because it was trying to read the bytes at port too quick. I need it to read a whole line so I can extract the values I want and it was reading 2 or 3 bytes at once. I have attached the updated vi. I tried to attach the block diagram but it didnt work so I will investigate that..sorry. Thanks again for all the advice. Liz :-)

I have a While Loop that reads data from the serial port. I then have another While Loop within this that processes the data received from the port one line at a time - an iteration for each line. The inner loop uses the match pattern function and extracts values before passing on the 'after substring' to be processed in the next iteration. The condition of the inner loop is stop when this string length is 0. This works until the first time the string is 0 then I cannot re-enter the inner loop when more data needs processing. I think it must be the loop condition but I am relatively new to labview and am not sure the best way round it! Any suggestions would be great :-) Thanks, Liz

Thanks for the advice. I think it is the serial read that is slowing the loop down as the timer seems to work fine in isolation! It just seems to take about 9 seconds to loop round and so if the time elapsed at the beginning of the loop there is a delay before anything is done about it.

I have changed te express vi so I am now checking against system time. The time needs to start at the visa write function just before the loop starts. I think I am missing something or have made an error as the timing is still not exact. I still have to wait a few seconds until the check time section is executed and the time reached triggered. I don't seem to have speeded the loop up to execute once every 100ms. I am relatively new to Labview so may be misunderstanding this completely! Attached is the updated vi Download File:post-10705-1204025858.vi

QUOTE(jdunham @ Feb 25 2008, 11:37 PM) Thanks - will try that :-)

I need a while loop to run for an exact number of minutes whilst reading data from the serial port. I am currently using the elapsed time function but instead of looping for precisely one minute it will run for about 1 minute 20 seconds because it checks the time at the beginning of the loop and if the minute is reached just after the last check it takes several seconds to reach the check point again. Ideally I would like the user to select the number of minutes for the run and for data to be read from the serial port for this time exactly and no more. Any advice would but be great :-) Thanks Download File:post-10705-1203941249.vi