Seeking Advice on NI DAQ for Flow Meter

[Dibya9]

Hello everyone,

                        I have a technical query regarding our setup, and I'd appreciate your insights and recommendations. We are currently using a flow meter to measure flow speed in our experiments. Initially, we were using a PLC (Programmable Logic Controller) to read these signals, and it worked well for short durations. However, as our experiments needed to run for several hours, we encountered issues with the PLC losing connection after a few minutes of operation.

We are considering switching to an NI DAQ (National Instruments Data Acquisition) system to address this problem. The minimum requirements for the DAQ system are as follows:

• 13 outputs
• 6 inputs
• Input signal: Pulse
• Output: 24V DC with variable current

Could you please recommend an NI DAQ system that satisfies these criteria?

Thank you in advance for your assistance.

[santo_13]

Tell us more about the input/output signal levels (digital or analog), link or model of your flow meter and other complex sensors that you may have.

Can you describe your experiment better?

[Dibya9]

We are using a QS100 inline irrigation flow sensor (6 of them). They generate a pulsed signal, which we need to read. Based on the speed of the flow, we want to control the 3-inch self-priming centrifugal pumps. To control the pump we are using a VFD, the input for this is 24V DC with variable currents. So our requirement is we need to read the signals from the flow sensor and send that information to the VFD, through which we want to control the pump. 

[santo_13]

So you need to support 6 x QS100 flow sensor that outputs pulses.

Can you share more details on how to control the VFD? does it use 0-5V or 0-10V or 4-20mA signal?

[Dibya9]

Thank you, Santosh.

The VFD uses 24V DC as an input, which we used to get from PLC. 

[Dibya9]

I missed one thing. We also have Valworx Valves (EPS 5618 series), which we are using to control the speed of the flow. The input for the valves is 4-20 mA. And it required 24 V for the power. We used to get both these values from the output of PLC. 

[santo_13]

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@Dibya9 wrote:

Thank you, Santosh.

The VFD uses 24V DC as an input, which we used to get from PLC. 

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Do you mean 0-24V to set the speed? how does do you tell the VFD to change the speed? typically it is 0-5V or 0-10V or 4-20mA. Better to have the VFD model or link to its manual/spec.

Can you reply with summarizing all the data you've shared so far?

[Dibya9]

Sure, 

       This is the summarized version of all the data.

System components:

     1. 6 QS100 inline irrigation flow sensors with output frequency: 0-100 Hz and 4 mSec Output pulse width.

     2. VFD (Variable Frequency Drive) for pump speed control, using 4-20 mA input. (Note: we are unsure about the 24 V external power source requirement.) 

   3. 6 Valworx Valves (EPS 5618 series) for flow control after the pump, with input signal: 4-20 mA. 

In summary, we require minimum:

   - 6 inputs (0-100 Hz).

   - 7 outputs (4-20 mA). 

Could you please recommend an NI DAQ system that satisfies these criteria? If I am missing any critical details or if you need further information, please feel free to point it out.

Thank you in advance for your assistance.