Would like to see if Moku:Go can be used as autonomous instrument to measure FRA of a shuttle of liquid samples. When the sample has been pumped to the sensor we would like the pump controller to be able to send a trigger signal to Moku to start FRA analysis and for Moku to return a signal when the measurements are complete. This is early stage exploration but ultimately we will be trying autonomous measurement of CO2 versus depth, deep in the ocean.
Hello Pol, thank you for posting to the Liquid Instruments forum!
This is a great question and use case, I would be happy to help you with some exploration to see if Moku:Go can work for your system. Would you be using the Python or MATLAB API for this automation?
Either way, I believe the application you are describing is possible with Moku:Go. It is possible to swap instruments rather quickly (within seconds) so that the Moku:Go can be in Oscilloscope mode waiting for a trigger signal, then once it is received the Moku:Go can be switched to the FRA instrument and perform a sweep. The FRA can return frequency, magnitude, and phase measurements and can gather up to 512 data points per frame. You can continuously log data by repeating the get_data() frame grab command, however there is no way to continuously log data in the FRA so the logging speed will be limited by the latency between the computer and the Moku:Go.
Please let me know if you have any other questions! You may find this API page useful as well.
Sam, thanks very much for your quick response.
We are just beginning to learn about capabilities and options of the Moku. We have a MATLAB license so we can choose either API. For now our challenge is accuracy rather than speed - typically we repeat the impedance sweep many times as we draw the sample across the electrodes, so I will look at items such as averaging duration and cycles as well as repeat get_data() timing. However, one of the reasons we are looking at the Moku instead of off the shelf mini-impedance systems is because we want to try new measurement ideas (our requirements for accuracy are really challenging and impedance has never been used for this application as a sensor mechanism). So I would like to try measuring two sensor cells (almost) simultaneously - one reference and one analyte and then measure the difference signal. I will need two O/P signals to provide the freq. sweeps and two input channels to capture the data. There, the timing might be more critical - so we may try to merge the output signals on the sensor itself - but that means we will be looking to read a difference signal.