Can't differentiate between two connected serial dongles

[bbracale]

I have two IOGear GUC232A adapters (PL-based) that I use with Serial Tools.  IIRC, in the past when I used the Serial Analyzer function with these adapters, Serial Ports A & B were identified separately (there was some -suffix added to one of the adapters).  Now under Sierra, each port shows up in the dropdown with the same name.  So I'm not sure if the two different ports are actually being differentiated correctly by Serial Tools, and even if they are, it makes it difficult to determine which port is which until the device(s) under test elicit some traffic, which might not always be a desirable scenario. 

I understand that this might be more of a driver/OS thing than a Serial Tools thing, but it would be great if the Serial Tools app could address the issue to the extent possible.

[support]

I'm afraid it may not be possible to differentiate between the different ports as the port name is provided by the underlying OS. Maybe there is an additional interface parameter provided in Sierra which I didn't implemented in SerialTools, but that's going to be really hard to simulate without the adapter hardware.
Could you please post diagnostic information from "About This Mac" -> "System Report" -> "USB", showing details of the two GUC232A adapters.

Just as a side note, I have previous experience with some of the cheaper adapters (mostly PL based) which appear to be indistinguishable. I solved the problem by getting a couple of FTDI based adapters which don't suffer from this issue.