<p>I have written a standalone app that controls a device through RS-232 port and some customers want to be able to use the device with LabVIEW.  I have seen some threads describing where to start when learning to use LabVIEW, but I was wondering if anyone has experience with writing a plugin/driver (is that the right word?) for LabVIEW and perhaps point me in the right direction.</p>

<p>The existing app is  GUI that allows people to control the device with higher level concepts - rather than have to know the syntax and protocol of the serial port comms stuff.  I want to abstract that away as well so that users can just plug something into LabVIEW and I suppose it exposes some verbs and methods that allow the device to be manipulated and also provide data to clients.  </p>

<p>I think there is a serial port interface from LabVIEW, but I am sure the people using this device do not want to have to write the code (parsers and etc) to communicate with the device.</p>

There are two options for what you're trying to do.
Create a DLL that users of your device can
call from LabVIEW
.
Rewrite your application in LabVIEW.
To reach the largest possible number of potential customers, option #1 would be the best solution for you.  If your customers are specifically asking for a LabVIEW driver then option #2 would probably be the least hassle for that specific customer.  The reason for this is that LabVIEW is very much a niche language (for automation and data acquisition), and for many LabVIEW developers it's the only language they know (or the only one they know well).