Ensure that the pen operates separately from the system cursor
Normally it is not possible for two users to operate separately on the same Windows session because this requires two system cursors and Windows does not allow this.
In addition Windows can only accept user input from the application or window which has the current system focus (selected by means of the cursor) and it is not possible for two applications or windows to have focus at the same time.
One way of getting round this problem is to configure the DTU for use in what is called "STU mode" - this means that it will only work with pre-specified applications which are definable on the Wacom tablet control panel.
In this scenario the PC operator would start the relevant application when ready and move it to the DTU - then the DTU user would be able to operate it with the pen.
For further details please see the DTU Operating Modes guide.
In conjunction with STU mode you can also use CXO_SYSTEM within your Wintab application to prevent the cursor from moving with the pen.
Alternatively there is a registry setting called SyncCursor which can be used with the Signature SDK or sign pro PDF to achieve the same end (during signature capture).
For further details on SyncCursor please see the Signature SDK API reference manual which is provided in the "documentation" folder of the Signature SDK download file (available from https://developer.wacom.com/en-us/developer-dashboard/downloads).
Please note however that STU mode does not allow concurrent input on the PC monitor and the DTU - its primary purpose is to prevent the DTU operator from taking over the system cursor except in pre-specified applications.
An second solution would be to write a Wintab application which allows the pen to operate independently of the mouse and keyboard by creating a dummy cursor for the pen.
The following two programs which show examples of this:
These samples illustrate the basic principle - further programming work would be required to create an application suitable for local requirements.
The third and probably easiest solution would be to use the Wacom Ink SDK for multi-display which can be downloaded under "For multi-display" on the Developer Dashboard.