daq asisstant flowmeter sensor

[sgirgin]

Hi all

I have omega flowmeter sensor sent at attachment and i want to create daq assistant.What should i select?I mean it is a digital sensor thats why i am choosing acquire signal-counter input and frequency.Is that right?

Thank you

[mikeporter]

So do you have both the hall-effect sensor and the signal conditioning thingy? If so the output is a 4-20mA current loop.

If all you have is the sensor, the output is a pulse train, but a very messy one. Before you send it to a counter for freq input you will need to clean it up (think Schmitt trigger, open loop OP amp, that sort of thing).

Mike...

[sgirgin]

Mine is FTB-1302 type which is hall effeckt pickup.So does that mean it is a analog output?because you said 4-20mA current loop?

[GerdW]

Hi sgirgin,

reading manuals isn't your favorite task, isn't it?

The manual says (on page 6):

The sensor detects the rotation of the flow meter’s gears and emits a frequency signal proportional to flow. The output signal is a square wave pulse which has a duty cycle of approximately 50%

Does it mention any analog values here?

Page 7 shows the wiring and explains voltage levels: you will definitely need some additional electronics (as suggested before) to connect that sensor to your DAQ device!

What kind of DAQ hardware do you (intent to) use?

[sgirgin]

I am aware that it has a frequency output.I am using NI USB 6229 BNC Daq device.

[GerdW]

Hi sgirgin,

I am aware that it has a frequency output.

That wasn't clear from your last message…

Your USB6229 has counters able to measure the frequency of your sensor signal. All you need to do is wiring some suitable electronics to convert the signal levels and provide TTL-compliant pulses to your PFI inputs. Then open the example finder and start an example VI to measure a frequency signal…

[sgirgin]

Ok as for the wiring i am not good in electronic circuit, from the user manual of sensor do i need to wire a resistance if so how?

[Dennis_Knutson]

It is merely saying that the source impedance is about 40 ohms. You wouldn't wire a resistor anymore than wiring a diode or switch.

[GerdW]

Hi sgirgin,

get someone familiar with those (basic!) electronic circuits...
No, you don't need to wire this resistor as it's part of your sensing device. You need a circuit to adjust voltage levels and pulse edges - as mentioned before...

[sgirgin]

without circuit i wire it oscilloscope and shows me like that.Isn't it too much it gives me like 50V