RS-232 Communications Adapters
Many USB to serial adapters have incomplete or incorrect RS-232 implementations. There are many that we have tested and have found to be defective.
The Keyspan (below) is the only USB to RS-232 device we recommend for adding single serial ports to your computer.
MOXA makes devices that are usually very good. The multi-port unit is shown below.
Tripp-Lite Keyspan - USB to Serial Port Adapter
| The brand that we know works well is the Tripp-Lite Keyspan. | 
MOXA UPORT - USB to Multiple Serial Ports Adapter
| In the MOXA Uport line, you can purchase units that go up to 16 ports through a single USB port. | 
 
      
      
        
