benclifford

I have an Analog Discovery 2 and Analog Discovery 3 test and measurement board each with an impedance analyser daughter board connected but I am having issues trying to use these at the same time to measure 2 separate resistive devices located approximately 15cm apart. Both of these setups work fine independently using both the Waveforms application and an adapted python script based on the one provided in the SDK but whenever the second Analog Discovery is powered (via USB) a strange "noise" appears in the results. This noise takes the form of a sine wave in the mHz range that the resistance is superimposed on as per the attached file. If I start the measurement on the second board the noise remains and if I have both boards connected to independent PCs the noise remains. My measurements settings are 1kHz frequency, 200mv amplitude, 0 offset, 0 averaging and using the 100 Ohm reference resistor. The Analog discovery boards are connected with the provided USB cables and the wires between the impedance analyser daughter board and the DUT are screened. This issue is seen on both boards no matter which one is connected first. I have confirmed these artefacts are not from the DUTs by measuring using the same settings on a BioLogic potentiostat. Do you have any ideas as what might be causing this behaviour and any suggestions to resolve this to allow multiple Analog Discovery boards to be used in parallel. Kind Regards, Ben