Choosing a design pattern for duplicate processes

[Lachy]

I need to create an application that controls and aquires data for two basins in a wastewater treatment pilot plant. Both basins go through the same series of states aerobic, anoxic, settle and decant but at different times (and therefore need to be controlled independently). Can I run two state machines in parallel or would it be best to use a different design pattern altogether (eg Master/Slave)? The application is intended to be run off a FP-2010.

[Tom_Hawkins]

You certainly can run two state machines in parallel - maybe you could put the state machine in a re-entrant subVI and place two copies of that subVI on your top-level diagram, passing in different parameters to specify e.g. interface channels and output filenames. If it's not possible for two independent VI's to communicate directly with your I/O hardware then they could use e.g. queues to communicate with a separate I/O process. Queues could also be used to communicate with a user interface process if that's required. I guess the choice is influenced by how important it is for your solution to be re-usable and scalable.