You need to provide more information for us to help you. There are many architectures to choose from and almost any architecture can be used to solve almost any problem but some are more suitable than others - it depends a lot on the complexity of your application and what you need to be able to do with the PLC.
For example, are you logging data? What are your timing requirements? Are there any safety concerns? What data do you need to display and in what forms (e.g. graph?)? Are you doing any sort of control and/or sequencing? Do you need to respond to certain events (e.g. from the user or the PLC)?
If all you're doing is reading/writing from a PLC then you might be able to do this with a simple state machine. A slight expansion on that would be to have an event based producer/consumer - the producer handling the user operating the front panel and the consumer dealing with communications to/from the PLC.
LabVIEW Champion, CLA, CLED, CTD
(blog)
