Users might be surprised to find out that inserting an SD card into the on-board SD card reader on the client machine is not detected in an existing Citrix session. 

On the other hand someone else is able to read a SD card inserted during an ICA session, or possibly when a user connects to an ICA session from work computer the new SD is redirected in ICA session but not when using another laptop as client machine.

What's the difference?  Why does it work sometimes and not others?  The answer is: it depends on how the SD Card Reader is attached to the computer.  

To find the difference, find out what bus the SD card reader is attached. 

1. Insert an SD card into the on-board or built-in SD card reader.
2. In WindowsOpen Device Manager.  (devmgr.msc)
3. Identify SD Card in the list.  It is usually under 'Disk drives'.
4. The default view in Device Manager is 'Devices by type'.  For this process, change the view to Choose View --> 'Devices by connection'

• Sample PCIe attached SD Card shown by connection:                                                                 

 

• Sample USB attached SD Card shown by connection:            

 

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Problem Cause

What difference does this make when inserting an SD Card during an existing Citrix session?

Citrix monitors the USB Bus all during the session.  Changes, as determined by policy, are redirected to the existing session.

The PCI bus, (or PCIe Bus) is not monitored.  Additions or removals to the PCI Bus are not redirected to an existing session.

SD Cards can be attached to the USB bus or the PCI bus.  Newer hardware uses the faster PCI Bus for the built-in SD Card reader.

SD Cards can be attached to the USB bus or the PCI bus. Newer hardware uses the faster PCI bus for the built-in SD Card reader.