If I plug a two serial devices into usb adapters both into a single USB hub will my computer see two different COM ports? - Super User
splitter - Is there a device with multiple serial ports to configure multiple devices - Super User
Multiple Serial Connections - Programming Questions - Arduino Forum
arduino - Switch between two serial ports - Electrical Engineering Stack Exchange
Serial Port Splitter - Share dataflow of one serial port among several applications or join dataflow of several serial port devices to one application.
Connect two serial port into one serial port - Stack Overflow
Difference between Serial Port and Parallel Ports - GeeksforGeeks
Amazon.com: Your Cable Store 1 Foot DB9 9 Pin Serial Port Y Cable 1 Male / 2 Female RS232 5 Pack : Electronics
serial - Connecting 4 devices on RS232 - Electrical Engineering Stack Exchange
Pololu - 4.3. Connecting a serial device
7.2.2 About Connecting to Multiple Device/PLCs
Compact RS-232/422/485 Serial-to-Ethernet | Digi One SP | Digi International