NI 9203 to 4-20mA Flow Meter

[philhway]

Hi,

I have a NI9203 Module, an NI PS15 power supply and an Omega FV103 flowmeter (http://www.omega.com/ppt/pptsc.asp?ref=FV100#ManualList) - i've attached the wiring diagram to this post from pg 7 of the manual.

(am using labview and a cRIO 9074 but that is all working fine)

I'm trying to wire them up but am not sure exactly what I need to wire to what.

I currently have:

+24 VDc wire from flow meter to + on the power supply

-24 VDc wire from flow meter to - on the power supply

4-20mA signal out wire from flow meter to the AI0 on the 9203 module

Is the above correct, and do I also need to wire something to the COM port on the 9203?

Thanks in advance for any help,

Phil.

[Stephen_C]

Hi Phil,

The COM is usually connected to the sensor gound to prevent ground loops.

From the image on their website it looks like you should connect COM to pin3.

Let me know how you get on.

[philhway]

Thanks Stephen

I currently have Pin3 wired to the negative side of the power supply (see figure in the attachment of my first post which explains the pin assignments on the flow meter a bit more thoroughly) - does that mean pin 3 needs to be wired to both the neg side of the power supply and to the COM port? (I just want to clarify before I try to ensure I don't so any damage to the flow meter / NI module by wiring up incorrectly)

I currently have:

Pin 1 (+24 VDc wire from flow meter) to + on the power supply

Pin 3 (-24 VDc wire from flow meter) to - on the power supply

Pin 2 (4-20mA signal out wire from flow meter) to the AI0 on the 9203 module

Thanks again for your help

Phil

[Stephen_C]

Hi Phil,

It seems to be the case that the pin needs tying to both com and power supply negative terminal, this would then be a common ground with the pump supplied with the 24V from the power supply.

Kind regards,

[philhway]

Hi Stephen,

Thanks for your help to date,

I have tried wiring as you suggested above but I am still not recording any measurements from the 9203 module. I have tried changing the scaling factors (I've seen some forums on here that state that instead of scaling using mA i.e. 4 and 20, you have to use the A values to scale i.e. 0.004 and 0.02.

The flow meter itself seems to be working fine (it has a digital display which is showing the flow readings).... can you suggest anything else I could try?

Thanks

Phil

[Stephen_C]

Hi Phil,

Is it possible for you to measure the current output using a digital multimeter to confirm the output from the flowmeter?

Regards,

[philhway · Accepted solution]

Hi Stephen,

I checked with a multimeter and the flowmeter is outputting the signal correctly......I disconnected and re-connected everything and it looks like it's working fine now (perhaps one of the wires wasn't clamped in correctly or something)

Thanks for your help,

Phil

[Stephen_C]

Thats great to hear Phil.

Good luck with the rest of your application.

[scott_white85]

nice thread huh! anyway goodluck philhway. hope to see the result.
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Electromagnetic Flowmeter is an industrial process control and instrumentation which can be used for flow measurement of sewage, water/wastewater, slurries and electrically liquids sludges. It has also many applications in industries such as building automation (HVAC), F&B, Chemical, Pulp&Paper etc.