How I Connected My Transcend Micro CPAP to an M-Series Mac

Overview

Running the Transcend MiniCPAP software on an M-series Mac (in my case an M4 Pro) inside Parallels Desktop was not plug-and-play.
Windows 11 ARM detected the Transcend Micro as an FT230X Basic UART, but no suitable driver was available.

The trick was understanding that the Transcend Micro uses an FTDI FT230X USB-to-serial bridge.
The solution required using the correct ARM64 VCP driver, editing its .inf file so Windows would accept it, and working around a Parallels path issue.

My setup

Mac: MacBook Pro M4 Pro
Virtualization: Parallels Desktop 19
Guest OS: Windows 11 ARM64
Device: Somnetics Transcend Micro CPAP
Goal: Run the Transcend Mini software for syncing and configuration

Step 1: Download the ARM64 FTDI VCP driver

Go to the FTDI VCP driver page:
ftdichip.com/drivers/vcp-drivers

Download the Windows 11 ARM64 “Universal Driver for ARM64 (WHQL Certified)”.
At the time I installed it, the version was v2.12.36.20.

Unzip the file inside Windows. This matters later.

Step 2: Add the CPAP hardware ID to the INF file

When I first connected the Transcend Micro, Windows showed these Hardware IDs:

USB\VID_0403&PID_6015&REV_1000  
USB\VID_0403&PID_6015

If your ftdibus.inf does not list PID_6015, add it manually.

In the [FtdiHw] section:

%USB\VID_0403&PID_6015.DeviceDesc%=FtdiBus.NT,USB\VID_0403&PID_6015

In the [Strings] section, add:

USB\VID_0403&PID_6015.DeviceDesc = "FT230X USB UART"

Some newer ARM64 driver packages already include this hardware ID.
If you see it listed, you can skip editing the file.

Step 3: Move the driver folder to a true Windows path

This is the part that cost me the most time.

Parallels maps your Mac Downloads folder as something like:

\\Mac\Home\Downloads\

Windows views this as a network path, and Windows cannot install kernel-mode drivers from a network location.

Fix it by copying the driver folder into a real Windows directory, for example:

C:\Users\<YourName>\Downloads\CDM_ARM64\

Once it is on a local NTFS path, Windows can install it.

Step 4: Install the drivers manually

Open Windows Terminal as Administrator and run:

pnputil /add-driver "C:\Users\<YourName>\Downloads\CDM_ARM64\ftdibus.inf" /install  
pnputil /add-driver "C:\Users\<YourName>\Downloads\CDM_ARM64\ftdiport.inf" /install

You can also install through Device Manager, but pnputil gives clearer feedback.

Unplug and reconnect the CPAP, or use Parallels:
Devices > USB and Bluetooth > reconnect the FT230X device to Windows.

Windows should now detect and install two devices:

USB Serial Converter (FTDI bus)
USB Serial Port (COMx)

Step 5: Verify it is working

Open Device Manager and look under Ports (COM and LPT).
If you see something like:

USB Serial Port (COM3)

everything is working correctly.

Step 6: Install and run the Transcend Mini software

Download the software from Somnetics:
https://mytranscend.com/software

Install it inside Windows.
When the app launches, it should connect to the CPAP automatically.
If it does not, check the COM port setting in the app and match it to the one shown in Device Manager.

Results

After reinstalling the driver from a proper local path, unplugging and reconnecting the CPAP, and rebooting once for good measure, the Transcend Micro showed up on COM3.
The Transcend Mini software synced and exported data without errors, all inside Parallels on my M4 Pro.

Why I shared this

This shows how to approach a weird cross-platform problem:

Figure out the actual chipset a device uses
Match the right driver architecture
Update the .inf with the correct hardware ID
Understand the impact of Parallels path mappings

The only help I found online was a brief forum post that hinted at FTDI but did not cover the ARM64 driver, the missing hardware ID, or the Parallels path problem.
I hope by sharing this that is saves someone else a few hours of trial and error.

Note A CPAP is a medical device and you should work with your Doctor to make any adjustments.