Windows 7 Virtual Pc Serial Ports
Ever since the original IBM PC, personal computers have been equipped with one or two serial ports, also called COM ports by DOS and Windows. Serial ports were commonly used with modems, and some computer mice used to be connected to serial ports before USB became commonplace.
windows 7 virtual pc serial ports
While serial ports are no longer as common as they used to be, there are still some important uses left for them. For example, serial ports can be used to set up a primitive network over a null-modem cable, in case Ethernet is not available. Also, serial ports are indispensable for system programmers needing to do kernel debugging, since kernel debugging software usually interacts with developers over a serial port. With virtual serial ports, system programmers can do kernel debugging on a virtual machine instead of needing a real computer to connect to.
If a virtual serial port is enabled, the guest OS sees a standard 16550A compatible UART device. Other UART types can be configured using the VBoxManage modifyvm command. Both receiving and transmitting data is supported. How this virtual serial port is then connected to the host is configurable, and the details depend on your host OS.
Host Device: Connects the virtual serial port to a physical serial port on your host. On a Windows host, this will be a name like COM1. On Linux or Oracle Solaris hosts, it will be a device node like /dev/ttyS0. Oracle VM VirtualBox will then simply redirect all data received from and sent to the virtual serial port to the physical device.
Raw File: Send the virtual serial port output to a file. This option is very useful for capturing diagnostic output from a guest. Any file may be used for this purpose, as long as the user running Oracle VM VirtualBox has sufficient privileges to create and write to the file.
Up to four serial ports can be configured per virtual machine, but you can pick any port numbers out of the above. However, serial ports cannot reliably share interrupts. If both ports are to be used at the same time, they must use different interrupt levels, for example COM1 and COM2, but not COM1 and COM3.
The Serial Console in the Azure portal provides access to a text-based console for Windows virtual machines (VMs) and virtual machine scale set instances. This serial connection connects to the COM1 serial port of the VM or virtual machine scale set instance, providing access to it independent of the network or operating system state. The serial console can only be accessed by using the Azure portal and is allowed only for those users who have an access role of Contributor or higher to the VM or virtual machine scale set.
The serial console can be used to send an NMI to an Azure virtual machine by using the keyboard icon in the command bar. After the NMI is delivered, the virtual machine configuration will control how the system responds. Windows can be configured to crash and create a memory dump file when receiving an NMI.
By default, all subscriptions have serial console access enabled. You can disable the serial console at either the subscription level or VM/virtual machine scale set level. For detailed instructions, visit Enable and disable the Azure Serial Console.
Access to the serial console is limited to users who have an access role of Virtual Machine Contributor or higher to the virtual machine. If your Azure Active Directory tenant requires multi-factor authentication (MFA), then access to the serial console will also need MFA because the serial console's access is through the Azure portal.
The Azure portal or Azure CLI act as remote terminals to the virtual machine serial port. As these terminals can't directly connect to the servers which host the virtual machine over the network, an intermediate service gateway is used to proxy the terminal traffic. Azure Serial Console doesn't store or process this customer data. The intermediate service gateway that transfers the data will reside in the geography of the virtual machine.
If a user is connected to the serial console and another user successfully requests access to that same virtual machine, the first user will be disconnected and the second user connected to the same session.
We're aware of some issues with the serial console and the VM's operating system. Here's a list of these issues and steps for mitigation for Windows VMs. These issues and mitigations apply for both VMs and virtual machine scale set instances. If these don't match the error you're seeing, see the common serial console service errors at Common Serial Console errors.
The fourth generation of Com Port Redirector has been completely redesigned. It extends remote device management and control via Ethernet to a wider range of applications, such as those that are extremely timing sensitive or require complete serial line control. CPR v4 simplifies the process of creating and mapping virtual COM ports, while increasing the number of virtual COM ports that can be created to 255. All can be used simultaneously by the applications software. Designed with OEM customers in mind, CPR v4 is easily integrated into applications and includes built-in monitoring and diagnostics to simplify troubleshooting.
TruPort Technology combines the RFC2217 Com Port control protocol with Lantronix device server discovery and data handling technology, making a true end-to-end communications solution. Combined with Lantronix device servers, CPR v4 enables applications to see and change the baud rate, character size, stop bit, parity and line control communication properties, providing full control of remote serial ports. In addition to serial interface control, TruPort also includes remote buffer monitoring and control of Lantronix device servers. This is critical for sensitive applications requiring special data handling. Quick and easy setup is accomplished using the automatic device server discovery feature, which automatically detects, locates and adds Lantronix device servers into the CPR v4 management module, simplifying configuration.
Click OK, and if Windows warns you about a duplicate, ignore the warning and click Yes. Click OK and then OK to the port settings. Then close the Device Manager window. If you want to confirm the port change has indeed been made, click on Device Manager again and check the listed Ports. Now close the System Properties window. 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 be removed from the device manager when the USB cable is unplugged, even if an application has the virtual COM port open. 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.
The computer a shared device is connected to, such as remote machine or host, will function as the server. The virtual machine connects to it as soon as the remote access to serial devices is established and acts as the client.
VSPE is intended to help software engineers and developers to create/debug/test applications that use serial ports. It is able to create various virtual devices to transmit/receive data. Unlike regular serial ports, virtual devices have special capabilities: for example, the same device can be opened more than once by different applications, that can be useful in many cases. With VSPE you are able to share physical serial port data for several applications, expose serial port to local network (via TCP protocol), create virtual serial port device pairs and so on.
HW VSP is a software driver that adds a virtual serial port (e.g. COM5) to the operating system and redirects the data from this port via a TCP/IP network to another hardware interface, which is specified by its IP address and port number. HW VSP3 support even NT Services and 64 bit Windows 8 .
HW Virtual Serial Driver is intended primarily for devices produced by HW group, although it can be used for free as a universal driver that creates a virtual remote serial port, which redirects data to a predefined TCP/IP address and port.
In special applications (e.g. involving GPRS devices), the PC with the HW VSP driver can be set to operate in TCP Server mode, enabling the remote device to initialize the connection by sending any data to the remote port. Upon receiving RS-232 data, the converter establishes a connection with the PC and passes the data to the virtual COM port. Therefore, the scenario very closely resembles behavior of a real serial port.
Ability to run as a service has been the main reason for developing the new version. Running HW VSP as a standalone application requires starting it under a logged-in user and therefore prevents autonomous operation on Windows servers. (At this time, HW VSP fully supports Windows 2000 Server and Windows 2003 Server. Support for Windows 2008 Server is being tested.) In this mode, HW VSP consists of a client-side part (setup GUI) and a server-side part (the service itself). Parameters of a VSP running on a remote server can be easily changed from a local PC. However, in order to improve stability, only one user may access the service and change virtual port parameters at a time. Furthermore, since service administration requires administrator privileges, securing a VSP against misuse is as simple as not installing the client-side part.
COM port (Communication port) is the name for the port serial interface that can be found in a common computer(IBM compatible). Sometimes computers come with one or two physical COM ports (RS-232), while today's models don't have them ususally. However, the COM port does not necessarily refer to physical ports, but also virtual. Such ports are created when using USB-to-UART adapter, most notably used by FTDI and Croduino. Here are a few examples of such devices: USB modems, cell phones, RFID readers, card readers, and so on.