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Here you will find useful tools, utilities and diagnostics software for serial communication, including drivers and user manuals for all our products. Recommended reading: 5 Steps for Selecting the Right USB to Serial adapter. Microsoft-provided drivers for USB-IF approved device classes. For composite devices, use USB Generic Parent Driver (Usbccgp.sys) that creates physical device objects (PDOs) for each function. For non-composite devices or a function of a composite device, use WinUSB (Winusb.sys).
Versions supported
- Windows 10
- Windows 8.1
Applies to
- Device manufacturers of CDC Control devices
Microsoft-provided in-box driver (Usbser.sys) for your Communications and CDC Control device.
In Windows 10, the driver has been rewritten by using the Kernel-Mode Driver Framework that improves the overall stability of the driver.
- Improved PnP and power management by the driver (such as, handling surprise removal).
- Added power management features such as USB Selective Suspend.
In addition, UWP applications can now use the APIs provided by the new Windows.Devices.SerialCommunication namespace that allow apps to talk to these devices.
Usbser.sys installation
Load the Microsoft-provided in-box driver (Usbser.sys) for your Communications and CDC Control device.
Note
If you trying to install a USB device class driver included in Windows, you do not need to download the driver. They are installed automatically. If they are not installed automatically, contact the device manufacturer. For the list of USB device class driver included in Windows, see USB device class drivers included in Windows.
Windows 10
In Windows 10, a new INF, Usbser.inf, has been added to %Systemroot%Inf that loads Usbser.sys as the function device object (FDO) in the device stack. If your device belongs to the Communications and CDC Control device class, Usbser.sys is loaded automatically.You do not need to write your own INF to reference the driver. The driver is loaded based on a compatible ID match similar to other USB device class drivers included in Windows.
USBClass_02
USBClass_02&SubClass_02
- If you want to load Usbser.sys automatically, set the class code to 02 and subclass code to 02 in the Device Descriptor. For more information, see USB communications device class. With this approach, you are not required to distribute INF files for your device because the system uses Usbser.inf.
- If your device specifies class code 02 but a subclass code value other than 02, Usbser.sys does not load automatically. Pnp Manager tries to find a driver. If a suitable driver is not found, the device might not have a driver loaded. In this case, you might have to load your own driver or write an INF that references another in-box driver.
- If your device specifies class and subclass codes to 02, and you want to load another driver instead of Usbser.sys, you have to write an INF that specifies the hardware ID of the device and the driver to install. For examples, look through the INF files included with sample drivers and find devices similar to your device. For information about INF sections, see Overview of INF Files.
Usb Serial Driver
Note
Microsoft encourages you to use in-box drivers whenever possible. On mobile editions of Windows, such as Windows 10 Mobile, only drivers that are part of the operating system are loaded. Unlike desktop editions, it is not possible to load a driver through an external driver package. With the new in-box INF, Usbser.sys is automatically loaded if a USB-to-serial device is detected on the mobile device.
Windows 8.1 and earlier versions
In Windows 8.1 and earlier versions of the operating system, Usbser.sys is not automatically loaded when a USB-to-serial device is attached to a computer. To load the driver, you need to write an INF that references the modem INF (mdmcpq.inf) by using the Include directive. The directive is required for instantiating the service, copying inbox binaries, and registering a device interface GUID that applications require to find the device and talk to it. That INF specifies 'Usbser' as a lower filter driver in a device stack.
The INF also needs to specify the device setup class as Modem to use mdmcpq.inf. Under the [Version] section of the INF, specify the Modem and the device class GUID. for details, see System-Supplied Device Setup Classes.
For more information, see How to use or reference the Usbser.sys driver from universal serial bus (USB) modem .inf files.
Configure selective suspend for Usbser.sys
Starting in Windows 10, Usbser.sys supports USB Selective Suspend. It allows the attached USB-to-serial device to enter a low power state when not in use, while the system remains in the S0 state. When communication with the device resumes, the device can leave the Suspend state and resume Working state. The feature is disabled by default and can be enabled and configured by setting the IdleUsbSelectiveSuspendPolicy entry under this registry key:
To configure power management features of Usbser.sys, you can set IdleUsbSelectiveSuspendPolicy to:
USBClass_02&SubClass_02
- If you want to load Usbser.sys automatically, set the class code to 02 and subclass code to 02 in the Device Descriptor. For more information, see USB communications device class. With this approach, you are not required to distribute INF files for your device because the system uses Usbser.inf.
- If your device specifies class code 02 but a subclass code value other than 02, Usbser.sys does not load automatically. Pnp Manager tries to find a driver. If a suitable driver is not found, the device might not have a driver loaded. In this case, you might have to load your own driver or write an INF that references another in-box driver.
- If your device specifies class and subclass codes to 02, and you want to load another driver instead of Usbser.sys, you have to write an INF that specifies the hardware ID of the device and the driver to install. For examples, look through the INF files included with sample drivers and find devices similar to your device. For information about INF sections, see Overview of INF Files.
Usb Serial Driver
Note
Microsoft encourages you to use in-box drivers whenever possible. On mobile editions of Windows, such as Windows 10 Mobile, only drivers that are part of the operating system are loaded. Unlike desktop editions, it is not possible to load a driver through an external driver package. With the new in-box INF, Usbser.sys is automatically loaded if a USB-to-serial device is detected on the mobile device.
Windows 8.1 and earlier versions
In Windows 8.1 and earlier versions of the operating system, Usbser.sys is not automatically loaded when a USB-to-serial device is attached to a computer. To load the driver, you need to write an INF that references the modem INF (mdmcpq.inf) by using the Include directive. The directive is required for instantiating the service, copying inbox binaries, and registering a device interface GUID that applications require to find the device and talk to it. That INF specifies 'Usbser' as a lower filter driver in a device stack.
The INF also needs to specify the device setup class as Modem to use mdmcpq.inf. Under the [Version] section of the INF, specify the Modem and the device class GUID. for details, see System-Supplied Device Setup Classes.
For more information, see How to use or reference the Usbser.sys driver from universal serial bus (USB) modem .inf files.
Configure selective suspend for Usbser.sys
Starting in Windows 10, Usbser.sys supports USB Selective Suspend. It allows the attached USB-to-serial device to enter a low power state when not in use, while the system remains in the S0 state. When communication with the device resumes, the device can leave the Suspend state and resume Working state. The feature is disabled by default and can be enabled and configured by setting the IdleUsbSelectiveSuspendPolicy entry under this registry key:
To configure power management features of Usbser.sys, you can set IdleUsbSelectiveSuspendPolicy to:
'0x00000001': Enters selective suspend when idle, that is, when there are no active data transfers to or from the device.
'0x00000000': Enters selective suspend only when there are no open handles to the device.
That entry can be added in one of two ways:
Write an INF that references the install INF and add the registry entry in the HW.AddReg section.
Describe the registry entry in an extended properties OS feature descriptor. Add a custom property section that sets the bPropertyName field to a Unicode string, 'IdleUsbSelectiveSuspendPolicy' and wPropertyNameLength to 62 bytes. Set the bPropertyData field to '0x00000001' or '0x00000000'. The property values are stored as little-endian 32-bit integers.
For more information, see Microsoft OS Descriptors.
Develop Windows applications for a USB CDC device
If you install Usbser.sys for the USB CDC device, here are the application programming model options:
Starting in Windows 10, a Windows app can send requests to Usbser.sys by using the Windows.Devices.SerialCommunication namespace. It defines Windows Runtime classes that can use to communicate with a USB CDC device through a serial port or some abstraction of a serial port. The classes provide functionality to discover such serial device, read and write data, and control serial-specific properties for flow control, such as setting baud rate, signal states.
In Windows 8.1 and earlier versions, you can write a Windows desktop application that opens a virtual COM port and communicates with the device. For more information, see:
Win32 programming model:
.NET framework programming model:
Related topics
Here are the latest step by step instructions for installing a USB to serial cable plus identifying and changing your com port number. This works with all Windows operating systems.
The following procedure works with all of our cables including the Allen Bradley 1747-UIC, 1761-CBL-PM02, 1747-CP3, and 2711-NC13
Drivers Usb Serial (communication Classes
1. To begin, click the start menu and type 'Device Manager' and click the Device Manager link.
2. Without your USB to serial adapter plugged in, your Device Manager should look something like below.
3. Plug your USB to serial cable into your PC's USB port. Chances are the drivers are already installed. Look for it to show up under 'Ports (COM & LPT)'. If it does, then note the COM number at the end of the description and proceed to the software you are using it in. If it doesn't show up under 'Ports (COM & LPT)' then proceed to step 4.
Usb Serial Adapter Driver
4. If your cable does not show up under 'Ports (COM & LPT)' of the Device Manager then you need to install the drivers. They can be found in the PLC Cable Drivers section of our Drivers, Software, and Manuals page. Download them and extract the zip file to your PC.
5. Navigate to the 'Drivers for manual installation' folder and you will find two folders named CH340 and CP210.
6. Double click on the CH340 folder and you will find an EXE file in it. Right click it and select 'Run as Administrator'. Note that this will not work by double clicking the EXE file.
Usb Serial Converter Driver
7. Now navigate to the CP210 folder and then to the CP210x_VCP_Windows folder. You will see two EXE files, one for 32 bit and one for 64 bit. Right click the one that matches the processor of your PC and Right click it and select 'Run as Administrator'. Note that this will not work by double clicking the EXE file.
