My Ruida 6445 controller uses the FTDI FT245R USB 2.0 Slave to FIFO Converter with their Vendor ID 0x0403 and Product ID x6001:
The FT245R chip uses its own handshaking as an integral part of its design, by proper use of the TXE# line.
- When high: do not write data into the FIFO
- When low: data can be written into the FIFO by strobing WR high, then low.
- During reset this signal pin is tri-state.
So… I think what all of this means (after about two hours of reading) is that this design relies on the driver for throttling of the data. You know… what I think Oz already said (I just wanted to understand this all myself).
So, according to FTDI, utilizing the built in Apple VCP (Virtual COM Port) driver is supposed to work and is compatible with the FT245R as long as the PID and VID are not modified. And as I have found on my own controller, they are not.
I read that removing / uninstalling the FTDI driver from Big Sur or Catalina was a possible fix (as the installation of the 3rd party FTDI driver was causing an issue).
I also see that FTDI has released (as of May 18) a Beta driver for Mac OS X10,15 and macOS 11.
(and maybe for anyone stating they cannot connect or see their machine at all)… There is also a post on FTDI’s community where they discovered that a Wacom Tablet driver was preventing both their VCP driver and Apple’s VCP driver from attaching to devices and providing a COM port.
Just use an Ethernet cable (even if it is off of a USB to Ethernet adapter on the Mac as a second interface).
(I just spent a disturbing amount of time reading about all of this)