Voltage Variation Issue in Excitation Output Channels PXIe4330

[YuKeSh-yuki]

We are experiencing an issue with the excitation voltage output on our NI hardware. We have configured the excitation voltage to 5V, but upon measurement using a Fluke 6½ Digit Digital Multimeter, we are observing slight deviations across the channels.

Below are our observations:

• Channel 0: 4.983 V

• Channel 1: 4.984 V

• Channel 2: 5.003 V
• Channel 3: 4.974 V
• Channel 4: 4.984 V
• Channel 5: 4.983 V
• Channel 6: 4.977 V
• Channel 7: 5.013 V

We have ensured proper grounding and earthing connections, yet the measured voltages remain inconsistent across channels. The deviation is approximately 17 mV from the expected 5V on some channels.

we attempted to boost the excitation voltage, but encountered a limitation — the system indicated that this is a quantized excitation supply, and we were unable to fine-tune it. When increasing the voltage setting to 7.5 V, the output was still not stable or accurate; we measured approximately 7.478 V instead.

Please advise on any recommended steps for further diagnostics or correction.

[ZYOng]

Did you measure the voltage with or without the strain gauge connected?

Did you connect the remote sense terminals?

Did you measure at the strain gauge terminals or at the NI devices?

[santo_13 · Accepted solution]

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@YuKeSh-yuki wrote:

We are experiencing an issue with the excitation voltage output on our NI hardware. We have configured the excitation voltage to 5V, but upon measurement using a Fluke 6½ Digit Digital Multimeter, we are observing slight deviations across the channels.

Below are our observations:

• Channel 0: 4.983 V

• Channel 1: 4.984 V

• Channel 2: 5.003 V
• Channel 3: 4.974 V
• Channel 4: 4.984 V
• Channel 5: 4.983 V
• Channel 6: 4.977 V
• Channel 7: 5.013 V

We have ensured proper grounding and earthing connections, yet the measured voltages remain inconsistent across channels. The deviation is approximately 17 mV from the expected 5V on some channels.

we attempted to boost the excitation voltage, but encountered a limitation — the system indicated that this is a quantized excitation supply, and we were unable to fine-tune it. When increasing the voltage setting to 7.5 V, the output was still not stable or accurate; we measured approximately 7.478 V instead.

Please advise on any recommended steps for further diagnostics or correction.

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Looks like it is within the stated PXIe-4330/4331 Specifications - NI tolerances,