Yes it is possible. Compact FieldPoint RT controllers have ethernet and serial ports that could be used to communicate with PDA's. Communication through TCP or serial can be done in LabVIEW RT just as it is done in regular LabVIEW. National Instruments currently does not have any tools for PDA's specifically for this, so you would have to take care of the PDA programming and communication yourself. But to the Compact FieldPoint it would just be talking to a serial or ethernet device.
Regards,
JR Andrews
Application Engineer
National Instruments