I'll work it into the answer. Well it seems I needed to install a Mbed serial port driver for Windows mbed. I ran it and the computer huffed and puffed for a few minutes, finally producing a nice "mbed serial port COM3 " line in the Device manager! RtsEnable and DtrEnable were required in my case. Show 1 more comment. Sign up or log in Sign up using Google. Sign up using Facebook. Sign up using Email and Password.
Post as a guest Name. Email Required, but never shown. The Overflow Blog. Podcast Making Agile work for data science. Stack Gives Back Generic COM-port devices and some modems belong to the abstract control model subclass. The protocol is V. For compatibility with standard host drivers, a generic virtual COM-port device should specify the V. The communication interface has four class-specific descriptors and an endpoint descriptor. The header functional descriptor names the version of the CDC specification the interface complies with.
The abstract control model descriptor specifies what class-specific requests and notifications the device supports. More on those below.
The union functional descriptor identifies the interfaces that belong to the CDC function, which are typically the communication interface plus a data interface. The call management functional descriptor tells how the device manages calls. An interrupt endpoint sends status notifications to the host.
The data interface is responsible for sending and receiving the COM-port data. The interface descriptor Listing 3 tells the host the interface has two bulk endpoints, one for each direction. Each endpoint has an endpoint descriptor. Listing 3. The data interface provides two endpoints for sending and receiving COM-port data. After retrieving the descriptors from the device and assigning the CDC driver, the host polls the bulk IN endpoint for COM-port data and polls the interrupt IN endpoint for notification data.
When sending COM-port data to the host, a device indicates the end of a transfer by sending a short packet, which is a data packet containing less than wMaxPacketSize bytes. When a transfer has an exact multiple of wMaxPacketSize bytes, the endpoint returns wMaxPacketSize bytes in one or more transactions until all of the data has been sent. The endpoint then indicates the end of the transfer by responding to an IN token packet with a zero-length packet ZLP , which is a data packet with no data bytes.
Listing 4. Besides COM-port data, devices with asynchronous serial ports often exchange information relating to port parameters, status and control signals, and error states. The host uses class-specific requests and notifications to send and receive the information.
Figure 3. At this point, you are ready to use the virtual COM port in any application! Note that, if you unplug the USB device and plug it back in later, Windows will still remember the COM port assignment, so you won't need to go through this procedure again. However, there is a known Windows issue that affects most applications.
The virtual COM port will not be accessible even after the virtual serial device is reconnected unless the virtual COM port is released by the application prior to the reconnection, which may require closing the application first.
It is therefore recommended that the application be closed before the USB device is unplugged. There is, however, an issue when we are using a modern laptop or another computer that does not contain a serial port.
The resolution of this issue involves taking advantage of the power of Virtual Serial Port Driver. This professional-grade software from Electronic Team enables you to easily create connected pairs of virtual serial ports.
Using these steps, virtual serial ports can be used with the Proteus simulator even on computers that are not equipped with physical COM ports. Electronic Team, Inc.
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Olga Weis Nov 27, Virtual Serial Port Driver. Download day fully-functional trial period.
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