reseeting data from daq every second

[richardmp]

You will have to forgive me as i am on the very first few steps of the labview learning curve. I am trying to set up a program to log the results from a flow meter. The difficulty i am having is getting the result from each second to subtract from the value before it ( as the daq assistant just keeps counting up). I have set up a timer which sends a false signal ( using shift register ) every second which in turn effects a case structure.

ive included a screenshot of my progress thus far.

I would greatly appreciate the help. I would go on a course but i am but a lowly student without 2000 pound to go on a course.

[.aCe.]

I am not sure if this would help?

Also, did you realise that NI give students a massive discount on training courses? It is quite significant, you will be saving £££'s

[SimonH]

richardmp,

I'm confused as to what you're trying to accomplish.  Are you trying to determine how much the acquired value has increased each second?

If so something like this would probably work for you:

If this isn't what you are going for please elaborate on your application and I'll see what I can do to help.

Regards,

Simon

[richardmp]

all it is is a flow meter placed within a pipe. I want to be able to have the set up show me what the flow rate is each individual second.

[.aCe.]

Then use Simon's solution above, its configured give you data every second.

[richardmp]

ive tried but the daq assistant comes up with an error saying i can only configure to on demand recording.

[.aCe.]

Which DAQ are you using? Just an obvious question: Have you reconfigured the daq assistant in Simons' vi to suit your daq?

[richardmp]

i go into daq assistant select acquire signals> falling edge. Then when i try and set to continuous sample with 1hz it alerts me that there is an error.

ive had some luck with this ( see enclosed image) set up but i dont know if its " fit for purpose"

[.aCe.]

Thats no good really. Why dont you just post the vi, or a simplified one at least?

[richardmp]

here you go. I do apologise if i seem to be making silly mistakes. thankyou for the heads up about the student discount's. I'm meeting with my placement supervisor tommorow to see if i can get on a course in the new year 🙂