Moku output load settings

Support & Troubleshooting Software & APIs
1

I am looking for any further information about the output load settings for the Moku:Lab. The only explicit mention that I can find is a git release note from Apr 2018 that reads as follows:

“Pymoku cannot be told what load you’re placing on the output, and therefore assumes the common case of 50-ohm. Due to the Moku:Lab’s internal 50 ohm series termination, this means that a high impedance load may see at much as twice the requested voltage on the output.”

From reading the pymoku code-base on the github repository it doesn’t seem that this was ever changed. I also cannot see this anywhere in the Moku API for the Go/Pro devices.

Have I missed any documentation/has this feature been added? I wish to change the output load settings to 1MOhm with a python script as I can when I am using the Moku iPad App.

2

We recently released a large update for Moku:Lab and it now uses the same API as the Moku:Go and Moku:Pro. You can find help on changing the output impedance with Python here.

If you are still using the legacy version (pymoku), then there is no way to change the output load. This is because in reality the output load is not actually being changed like the input load can. The Moku:Lab’s output impedance is always at 50 Ohms, however, the “output load” setting in the app you see is an expected output load as seen by the Moku, which will only change the scaling of the peak-to-peak amplitude. This means, in pymoku, you just need to set the appropriate scaling manually based on the expected output load.

There is a similar post about this when using Multi-instrument Mode here that may be helpful as well.