This Unity plugin is used to send triggers with the MMBT-S Trigger Box from Neurospec AG.
Many devices require triggers to be sent via a parallel port, but these days many computers (especially laptops) do not have parallel ports anymore.
This little device basically serves as a USB-to-parallel port adapter.
After installing the driver that ships with the device, the trigger box will appear as a serial COM port.
SerialPort_MMBTS.cs can be used outside of Unity in a typical CSharp project.
Unity 2017.4.35f1 and newer versions
You need to set the Unity API Compatibility Level to .Net 2.0 in order to get access to System.IO.Ports