Interfacing different sensors using one NI 9203

[OsamaRiz]

Hi,

I am a beginner in the field of control and automation, and I have been assigned a task to install pressure transmitter and load cell on an existing equipment. The machine has an already installed NI 6003 DAQ which is there to control a programmable Power supply. Also the machine has thermocouples installed which are connected to NI 9212 isolated thermocouple module. 

Since I have to select both the Sensors for pressure and force measurement and the data acquisition module, I wanted to make it sure that things can integrate to each other seamlessly. 

In this regard, I have found a module NI 9203 which is a current input module. I wanted to ask this question to the field experts that if I select both pressure and load cell which have an output of 4-20 mA, would that mean that I could integrate module and sensors easily.

Would it also depend on the sensor type, for instance a pressure transducer of any type may it be bridge type, capacitive, piezo or other.... unless it has an output of 4-20 mA, it should work?

I appreciate your time and effort that you put while reading and responding to my query. Thanks a lot

Best Regards

Osama

[DMycroft]

Hello Osama,

To clarify, the NI 9203 is an 8-channel, 16-bit current input module designed specifically for signals in the ±20 mA range, making it ideal for 4-20 mA industrial sensors. If you select pressure transmitters and load cells that output a 4-20 mA current signal, the NI 9203 can directly interface with them without additional signal conditioning. This setup ensures seamless integration and reliable measurements.

Regarding sensor types (bridge, capacitive, piezo, etc.), the key factor for compatibility with the NI 9203 is the output signal format. As long as the sensor provides a 4-20 mA output, the underlying sensor technology does not affect compatibility. However, if a sensor outputs a different signal type (e.g., millivolt bridge output), you would need appropriate signal conditioning hardware to convert it to a 4-20 mA signal or choose a DAQ module compatible with that output.

Can I just check what Chassis model you are using (CDAQ or CRIO)?

Please let me know if you want to discuss specific sensor models or need help configuring the NI 9203 module with your system.

Thanks,

Dom

[OsamaRiz]

Hi Dom,

I truly am thankful for your detailed and explanatory response. 

Regarding the Chassis, the equipment currently have the NI 9212 cDAQ module installed. I have the picture at the moment which is attached below.

In this regard, I have one more question. Since there is a multifunction NI 6003 module installed in the equipment. Is it possible to use 6003 to read data from both pressure transducer and load cell if they have let's say 4-20 mA output. Is it possible that NI 6003 read the amperes and convert the corresponding value via a function to the physical property being measured. I assume that the sensor will come up with their calibration certificate and they generally operate in a linear function. 

Looking forward to your response.

Thanks a lot 

[santo_13]

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@OsamaRiz wrote:

Hi Dom,

I truly am thankful for your detailed and explanatory response. 

Regarding the Chassis, the equipment currently have the NI 9212 cDAQ module installed. I have the picture at the moment which is attached below.

In this regard, I have one more question. Since there is a multifunction NI 6003 module installed in the equipment. Is it possible to use 6003 to read data from both pressure transducer and load cell if they have let's say 4-20 mA output. Is it possible that NI 6003 read the amperes and convert the corresponding value via a function to the physical property being measured. I assume that the sensor will come up with their calibration certificate and they generally operate in a linear function. 

Looking forward to your response.

Thanks a lot 

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You can add an external resistor to convert the 4-20mA loop to Voltage for the USB 6003 to read and you can configure the DAQmx channel to read current with a external sense resistor and provide the physical scaling factors to get readings from DAQmx APIs in the physical units instead of mA or V.

Since the 6003 has a fixed +/-10V range, you need to scale the 4-20mA to +10V so you get the maximum resolution and accuracy. 

https://www.omega.co.uk/techref/das/4-20ma.html

You essentially need a 500 ohm or 499 ohm 0.1% resistor to give you the best measurement results.