What do you need to test Com ports?

To test COM ports, you need a computer with a functioning serial port or a USB-to-serial adapter, appropriate software for communication (like terminal emulation software), and a loopback connector or a serial device to connect to the port. Additionally, you may require a null modem cable if you are testing communication between two devices. Ensure that the correct COM port settings (baud rate, data bits, parity, stop bits, and flow control) are configured in the software.