04-13-2023 06:34 AM
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.
04-13-2023 09:55 AM - last edited on 06-05-2024 11:28 AM by Content Cleaner
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.
04-15-2023 08:57 AM
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_
04-15-2023 08:31 PM
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.
04-16-2023 04:15 AM
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.
04-16-2023 08:00 AM
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.