2.Double click the “Ports (COM & LPT)” and verify that all of the “USB Serial Port” settings are IDENTICAL to the following table:
Description | Location |
USB Serial Port (COM3) | On USB Serial Converter A |
USB Serial Port (COM4) | On USB Serial Converter B |
3.If they are not, and you see the assignments as shown below, then the operating system has reassigned these serial ports. You need to re‐assign (correct) them manually.