# Real-Time Measurement and Control

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## NI 9215 with BNC, Kraftmessdose//Force washer,Verkabelung/Wiring

Hi all,

I’m neu with Compact rio and working with CompactRio 9074 with Ni 9215 with BNC for my Masterthesis. Ich need to connect 4 HBM KMR 300kN Force washer with cRIO to watch the change of force. I followed the manual and connected the sensor to the power supply and NI9215. I didn't connect the force washer with the NI PS-16 Power Supply, because it output 10A. It is too high for the force washer. The crio readings are a bit strange, like the sensor is not energized. When I connected an amplifier with a distance sensor and then connected it to the crio via bnc, I was able to read the correct values successfully.

Is the problem that the 9215 is not a replacement for the amplifier? Does anyone know how I can solve this problem?

I hope someone can help me. Thank you.

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## Re: NI 9215 with BNC, Kraftmessdose//Force washer,Verkabelung/Wiring

NI-9215 is not suitable hardware to measure a force sensor. First, read Load Cell & Force Transducer - How It Works • ANYLOAD Weigh & Measure if you are not familiar with the working principle of a load cell.

Using the excitation voltage of 12 V, assuming the sensitivity of 2.3 mV/V, at the full range of 300 kN, the maximum output voltage is 27.6 mV

V_out = V_ext * Characteristics Value = 12 V * 2.3 mV/V = 27.6 mV

NI-9215 has an input range of +/- 10 V and 16-bit ADC, the voltage resolution is 20 / (2^16) = 0.3 mV

You should consider getting a strain input module. They have a built-in excitation feature and a smaller input range.

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## Re: NI 9215 with BNC, Kraftmessdose//Force washer,Verkabelung/Wiring

Thank you for your advice. I found NI 9219 in our Labor. I connect the Force washer to it. The minimal Range is 7.8mV/V. Is it ok? How should i set the gain, to get a correct Force reading? This is my setting for force washer, is it right_

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## Re: NI 9215 with BNC, Kraftmessdose//Force washer,Verkabelung/Wiring

NI-9219 should work. See Use NI DAQ Devices for Load, Pressure, and Torque Measurements to learn how to wire and configure the Force (Bridge) measurement task using NI-DAQmx.

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## Re: NI 9215 with BNC, Kraftmessdose//Force washer,Verkabelung/Wiring

Thank you for your advice. I would say, some of parts woks.

I only got Compact Rio 9072, it isn't a daq chassis. I wired as the manual says.

But it seems somewhere else ist wrong. I'm not sure, it's the problem from the sensor or from my settings. Can you help with that? I posted the Signal from labview of each sensor.

I multiplied the reading by 25000. In the first three pictures, when it increases, that means i press it. The last graph shows the exact opposite situation. Does it means, that i should switch the positiv/negativ wiring.

When I insert the ni 9219 into the 9074 chassis, do I need to install any plug-ins via MAX?

Thank you so much for you help.

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## Re: NI 9215 with BNC, Kraftmessdose//Force washer,Verkabelung/Wiring

Since you can read something from the cRIO + 9219, there is nothing else you need to install via NI MAX.

See Using Bridge-based C Series Modules with Compact RIO to do the conversion from mV/V to Newton.

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