omega flowmeter sensor daq connection

[MagnusJ]

HI all,

I am taking over a project from a previous graduate student. So, I have to learn on the fly. I am having trouble with my Omega FDP3203-D-A flowmeters reading to Labview. The set-up worked at one point previous to my taking over. At this point reading is always the same, no matter what flow I set at the pump. The flow graph shows either 0 flow or the same max value, which is around 1500LPH. There are three flow meters attached so I suspect they are reading max flow which is 500LPH. Hence the reading of 1500LPH in the Labview front panel.

I am trouble shooting this and learning software and hardware as I go.

Does anyone have any ideas?

[GerdW]

Hi Magnus,

am trouble shooting this and learning software and hardware as I go.

Does anyone have any ideas?

- Use the training resources offered in the header of the LabVIEW board to learn LabVIEW.

- Check your cabling. Use a DMM to check the output signal of your flowmeter(s) to better locate the problem (software or hardware problem?)!

- Which DAQ hardware do you use?

- When you need help with your specific VI you should attach that VI here in the forum!

There are three flow meters attached so I suspect they are reading max flow which is 500LPH.

Why do you "suspect"? Why don't you inspect (and debug) your code to know? (See points above.)

[nyc_(is_out_of_here)]

I searched on Omega's website.

Cannot even find FDP3203-D-A .

[MagnusJ]

Hi Gerd,

Thanks for your response. I should have included the VI. Which I will this time!

Okay, lets talk hardware:

The Omega flow meters FPD3203 (the 'D' and 'A' are designations for digital display and analog output), the 3 flow meters are wired into a NI-9203 module, Then a NI-9174 DAQ. This goes into the PC and read by the VI(attached).

I did not design this system, I just have to figure it out and fix it. It was designed by a group of engineering students last year. It apparently worked at the time. It does not now.

I suspect because I don't know enough at this point to be sure. I am just now learning the method used and the software. So the learning curve has been steep. I was sure the code was correct. It made sense to me, I followed each wire to the indicators and it was what I expected. But I'm sure I've reached the extent of my knowledge. I will read the training resources.

Thanks!

[RavensFan]

Use block diagram cleanup.  The VI is messy with many backwards running wires.

How are you running this VI?  Please don't tell me you are using the Run Continuously button.  I don't see any while loop in your VI which is what you should be using if you want this to run more than a single time.

Any clues as to what might have changed since it worked the last time and now?  Was the VI changed?  Were the flowmeters changed or the DAQ modules?  Settings within the flowmeter like what determines the analog output ranges?

[MagnusJ]

How are you running this VI?  Please don't tell me you are using the Run Continuously button.  I don't see any while loop in your VI which is what you should be using if you want this to run more than a single time.

I'm guilty of using the Run continuously button. probably a noob mistake. The guy who designed the code didn't know much more than I do now. I will look to incorporate a while loop.

Any clues as to what might have changed since it worked the last time and now?  Was the VI changed?  Were the flowmeters changed or the DAQ modules?  Settings within the flowmeter like what determines the analog output ranges?

I'm not really sure. My initial thought is that nothing has changed. Obviously, since it ran before, and doesn't now, something changed. That is what I am trying to figure out. The VI is the same, the flowmeters don't read the same as what comes out in Labview, so something is definitely wrong there. 

I am looking into K-factors for the flow meters. Is there a corresponding setting in the DAQ or the VI?

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[Ben_Manthey]

The documentation for  that flowmeter is crap. There isn't a wiring diagram for the 4-20 mA output but they do mention a 24 VDC Power supply. 
Do you have the power supply? Are there some mystery wires where the power supply used to be? Is the power supply turned on? Can you put a multimeter on the current out and see if i you get anything?

You could call Omega and have them send you a schematic for the mA out, they'll be their usual useless selves so good luck. 

[RavensFan]

He said that about the documentation.

Not about the flowmeter itself

[MagnusJ]

And he's right, the documentation is crap. We ended up going with another flow meter that seems to have worked out really well. As I mentioned, I inherited most of the equipment and tried to make do with what we had. Once I realized the meters weren't working for us, we switched them.

[AaronTeitlebaum]

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@Ben_Manthey wrote:

The documentation for  that flowmeter is crap. There isn't a wiring diagram for the 4-20 mA output but they do mention a 24 VDC Power supply. 
Do you have the power supply? Are there some mystery wires where the power supply used to be? Is the power supply turned on? Can you put a multimeter on the current out and see if i you get anything?

You could call Omega and have them send you a schematic for the mA out, they'll be their usual useless selves so good luck. 

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The documentation for the digital display and analog output module is separate and a little hard to find, but it's here: https://assets.omega.com/manuals/M5427.pdf