Reset Value to 0

[Anwar05]

Hello LabVIEW users..

I'm measuring flow using a flowmeter sensor and NI 6212. The flowmeter I use is a digital sensor type with a hall effect concept as shown in the attached picture. Everything is ok when the measurement is done, but when there is no flow through the sensor my indicator on the front panel shows the last number when measuring (latching), how do I reset the value to 0, if there is no flow through the sensor?

The code that I made is like the attached image.

I really respect for ur reply..

[Kevin_Price]

Start by asking this question - how can I detect a no-flow condition, such that I'll know if and when I should set the measurement to 0?

And here's my answer:  the call to DAQmx Read will return with a timeout error if no pulses are seen in the allotted time.  If you use a *reasonable* timeout error (instead of the 100 seconds you appear to be using now), you can detect it and react appropriately.   Say for example 2 seconds.  If you get an error back, check the error code and if it's a timeout error, you can set your flow rate to 0.

-Kevin P

[Anwar05]

Hi Kevin
Yes I mean how to detect no flow condition. I've changed the VI by removing the DAQ mx Start and Stop from the While loop. Unfortunately I had a problem with my sensor, now it can't read at all.
I'll let you know the progress, thank you

[Anwar05]

I have a flowmeter from Shanghai JSN with type CX-M2, every time we try the VI I made, I blow the flowmeter sensor from the inlet. Yesterday it was still running fine, but when I tried it today it can't work, I don't know what happened even though it didn't fall or anything. I have checked the signal output using an oscilloscope, it is always active high even though the sensor type is hall effect. Any solution for me?

[Kevin_Price]

No, sorry, I'm unfamiliar with the sensor and all the rest of what you're doing.  I only know about the data acq side of things, using NI's counters under DAQmx.

-Kevin P

[Anwar05]

Hi Kevin Thank You, I think my sensor was damaged due to over flow. 

[Anwar05]

Hi Kevin
I think my sensor was damaged due to over flow, Thank u. Perhaps i'll need ur help later.