NOTE ON CITRIX COMPATIBILITY
Native support for Wacom signature pads was introduced with Citrix 7.6.3 (Feature Pack 3) as documented at this What's New article.
At the time of writing (March 2022) the list of currently supported devices is here: Citrix supported devices
Similar information can be seen on Citrix's own Web site here: Citrix Compatible Wacom Pen Devices
If using any of our older pads please raise a Support Ticket.
For older versions of Citrix (of which the most common is probably 6.5) then you would need to use the 430V or the STU 540 in serial mode.
At the time of writing the maximum supported baud rate for these devices on XenDeskTop or XenApp 6.5 is 128,000 bits per second.
If in doubt please raise a support request at the link given above to request up-to-date information, especially if you want to use a different version of Citrix.