When the user tries to redirect USB device to Virtual Desktop, it is checked against each USB policy rules in turn until a match is found. The first match for any devices is considered final. If the first match is an Allow rule, the matched device is allowed to be redirected to the virtual desktop. If the first match is a Deny rule, the matched device is only available in the local desktop.

1. Open Desktop Studio on XenDesktop server and click Start > All Programs > Citrix > Desktop Studio.

2. Expand HDX Policy.

3. Select Users.

4. Click Edit > Settings.

5. In the Policy console, scroll down to USB Devices.

6. Click Add on Client USB device redirection rules.

7. Select Use default value and click OK.

   You can find the default rules in the following registry in virtual desktop:

   Caution! Refer to the Disclaimer at the end of this article before using Registry Editor.

   HKLMSOFTWARECitrixPortICAGenericUSBDeviceRules for 32-bit OS

   Or

   HKLMSOFTWAREWow6432NodeCitrixPortICAGenericUSBDeviceRules for 64-bit OS

Creating Client USB device optimization rules

In XenApp and XenDesktop 7.6 FP3, the Client USB device optimization rules can be applied to devices to disable generic usb optimization for interrupt devices, or to change the optimization mode.

When a user plugs in a USB input device, the host checks if the device is allowed by the USB policy settings. If the device is allowed, the host then checks the Client USB device optimization rules for the device. If no rule is specified, then the device is handled as Interactive mode (02). Capture mode (04) is the recommended mode for signature devices.

For more details follow link.

Settings for Audio redirection of XenApp (per user )

For Server OS enable audio through Generic USB from client policy, supported from Receiver 4.5 and XenApp / XenDesktop 7.8

For enabling audio redirection for logged in user you must perform following steps:

1. On Client copy receiver.admx from C:Program Files (x86)CitrixICA ClientConfiguration to C:WindowsPolicyDefinitions
   Note: For x86 Client instead of Program Files (x86) go to Program Files

2. On Client copy receiver .adml from C:Program Files (x86)CitrixICA ClientConfigurationen-US to C:WindowsPolicyDefinitionsen-US
   Note: For x86 Client instead of Program Files (x86) go to Program Files

3. On Client launch GPO by running gpedit.msc

4. Go to ComputerConfiguration->Administrative Templates->Citrix Receiver->User experience and right click edit “Audio through Generic USB Redirection”
   

5. Enable the policy and on client run gpupdate /force from command prompt
   

6. Launch XenApp session and redirect the audio device .

Settings for Specific USB Devices

Besides generic USB redirection, XenDesktop provides optimized redirection methods for some specific USB devices. Some advanced functions such as, data compression is provided by these dedicated virtual channels:

Using the USB Device Rules Policy

1. Open the Local Group Policy Editor and go to Administrative Templates > Citrix Components > Citrix Receiver > Remoting client devices > Generic USB Remoting.
2. Open the USB Device Rules setting and enable the setting. Add the USB Device rule as in this example,
   The Allow: VID=1230 PID=0007 rule allows the device with Vendor ID 1230 and Product ID 0007:
   Note:Use the Allow: VID=xxxx PID=xxxx rule when a specific device must be on top of the device rules list.

​
Note: Refer to Hardware/Device property details to find the Vendor ID or a tool like USBVIEW or on the Receiver Toolbar, go to Devices > Manage Devices > and mouse over on any device as shown in the following figure:

3. For Citrix Receiver 4.6 and lower, generally, the following USB Error appears when the device is in use on the endpoint. Identify the process using the device and kill it:

   “Device appears to be in use and cannot be attached. Close any…”

From Citrix Receiver 4.7 onwards, USB Error allows to forcefully redirect the device by clicking on Yes button

Workaround

Note: On Windows Receiver 3.0 version and later, there is a workaround to suppress the USB Error.

There is a registry setting available to force-redirect USB devices, even if a client-side application is using the device:

Optimizing User Sessions For Xenapp 6all About Citrix Free

1. Open HKLMSOFTWARECitrixICA ClientGenericUSB for 32-bit OS.

   Or

   HKLMSOFTWAREWow6432NodeCitrixICA ClientGenericUSB for 64-bit OS.

2. Set REG_DWORD value EnableForceRestartForHID to 1.

Additional Resources

Optimizing User Sessions For Xenapp 6all About Citrix Using

Citrix Documentation - Configure USB support