Hey folks. I bought the "Koolertron Upgraded 60MHz DDS Signal Generator Counter, High Precision Dual-channel Arbitrary Waveform Function Generator Frequency Meter 200MSa/s (60MHz) Model: GH-CJDS66-FU" awhile ago on Amazon, which I'm pretty sure is the 60 MHz version of this same device being discussed, although if it isn't the same one I apologize, and feel free to remove my comment.
Anyway, I wanted to control this device from the command line (on Linux specifically), and after reverse-engineering how to upload user-defined arbitrary waveforms, I emailed Koolertron and received an official English-language spec for the usb-serial communication protocol from Koolertron's customer support, and while I don't think they'll let me share the spec document, they did authorize me to use it to make an unofficial open source program based on the spec. It looks like it's the official English-language version of the same Chinese document someone translated on this thread.
So anyway, I made a cross-platform command line program (tested and working on Linux and Windows, might also work on Mac but untested) which implements nearly the entire spec (minus some small things from the spec which didn't work as advertised or didn't make much sense), and if you're interested in using it, or studying the code to infer the official spec for your own uses (as it was provided to me in the real English-language document), you can find the project here, I just released the first version this evening:
https://gitlab.com/defcronyke/signal-gen-cjds66I don't claim that it's perfect or anything, there's likely a few bugs in this first version, but it can be considered pretty much feature-complete, and maybe you'll appreciate it. Let me know if you have any questions or opinions on it, and if you'd like to propose any changes to the program, you can do so through the gitlab project site (or I guess you can mention things in this thread, but I'd rather not hijack the thread). I made it for myself, but then I thought maybe other folks might find it useful, so if anyone else can get some use out of it then I'm happy.
----------
UPDATE 2021-01-07 - Linux and Windows x86_64 binary builds are now available with each new release from now on, so you don't have to compile from source yourself (now at v0.1.6):
https://gitlab.com/defcronyke/signal-gen-cjds66/-/releases