PXIe-4492

[kangyaxiong123]

PXIe-4492 has sine wave when it is connected with an extension line. What is the problem?

[santo_13]

Need more context and details.

[kangyaxiong123]

Thank you for your reminder, it is the first time for me to ask for help in the forum, so I ignored many details.PXIe-4492 acquisition card, connected to shb4x-8bnc, has a sinusoidal waveform under no-load condition. The connection condition and waveform display are shown in the figure.

[santo_13]

Any high impedance input must not be left floating as it will pick up electromagnetic interference. It looks like it is picking up 50Hz power line interference from your nearby electrical cabling or appliances.

https://knowledge.ni.com/KnowledgeArticleDetails?id=kA00Z000000P6TeSAK&l=en-US

This is not a problem and expected behavior.