Justin,
not being sure that I got you right, what about using a multiple serial port extender setup?
There are several suppliers for serial port extenders. I am using a test setup with 26 serial ports, from which 24 are provided by a Moxa C320 system. Those systems can provide up to 32 serial ports (with up to 460 kbaud) with a PCI card for the PC. One can use up to 4 of such cards in one PC; so reaching up to 128 extra serial ports. Driver supply is very good. Those extra ports show up in the system and in MAX as 'normal' serial ports. and can be used as such.
In my test system I have up to 8 parallel running processes that communicate with two serial ports each.
When considering USP2serial adapters, take into account the availabel bandwidth when having multiple serial connections on one USB channel. AND USB _may_ introduce a more or less important variable delay when carrying smaller messages. Thus, a single command like "Go" or so _may_ be sent to the device immediately, but _may_ as well be delayed by up to about 1 second. And there's nothing you or LabVIEW or VISA can do, this is a property of the USB2serial adapter driver.
HTH and
Greetings from Germany!
--
Uwe