Weird Noise in AIB Analog Input

[Matias_Guzman]

Hi all,

With my team, we are trying to solve a problem that involves a Biosemi AIB Analog Input, a Kistler DAQ and a Kistler Multicomponent Force Plate.

Specifically with the Biosemi AIB, we connected the input to an oscilloscope (ground to pin 37 and probe to channel pins as stated in this page https://www.biosemi.com/faq/pin_connections_aib.htm) and get the next images:

TEK0003.JPG (200.37 KiB) Viewed 16267 times

TEK0002.JPG (172.12 KiB) Viewed 16267 times

TEK0001.JPG (225.46 KiB) Viewed 16267 times

If we are not wrong, and since those are Inputs, we should read high impedance and not a sinusoidal wave of not negligible peak-to-peak value of roughly 50 Hz. Is this the expected behavior of the Analog Input of an AIB? Or are we dealing with a defective device?

Also, we had a hard time finding a detailed datasheet of this device, all the info came directly from this webpage https://www.biosemi.com/aib.htm. We were wondering if we could get more information from another source that we might have missed?

Any help would be really appreciated

Best regards,

Matías

[Coen]

50 Hz pickup is normal when measuring on an unconnected (floating) high impedance AIB input.

Connect the analog outputs of your Kistler Multicomponent Force Plate to the AIB inputs and inspect the signals in ActiView. You do not need the Kistler DAQ, the BioSemi AIB is the Data Acquisition System in this case.

Best regards, Coen (BioSem)