The WinSSD utility of SeaMAC for Windows gives you access to all the communication options of Sealevel PCIe and PCI synchronous serial cards necessary to create a loopback test. This includes many options you can combine for a valid communication configuration, and the options to electrically join the data transmit and data receive signals together inside the card. Optionally in place of the latter, you can wire output pins to inputs pins in the serial port.
The factory default communication configuration is valid for a loopback test. In the SeaMAC Configuration Utility, choose the port you would like to place in a loopback, and restore its factory default configuration by selecting this option in the Settings menu. Confirm to overwrite the old settings.
To use a software enabled loopback mode, enable the Internal Loopback option for the port in Settings. If you have wired your own loopback between the pins of the connector, select an Electrical Interface in Settings that will enable a compatible pinout for the port. After you set the configuration, use the features of WinSSD to conduct testing.