The “BTA” analog port on the Go Direct® Force Plate (GDX-FP) is designed for the Lateral Force Accessory (2D-FP). When this accessory is connected to the port, you can activate the Lateral Force channel to get sensor data.
You can also connect other analog sensors with the same BTA connector. In this case, activate the Auxiliary Voltage channel. This will provide the raw voltage from any Vernier LabQuest sensor. You can then apply the calibration equation (found in most User Manuals) to create a calculated column to get sensor values.
This opens the door to many creative activities that combine the force plate with other sensors.