JLCooper eBOX - Manual (Page 39)

Unlike serial ports, where the input and output signals are carried
over the same cable, and are usually going to the same device, GPI
inputs and outputs are separate entities. They may or may not be
connected to the same device. This is why they can be
programmed independently. However, when an input and output
pin is connected to the same device and you want them both to
perform the same actions, you can program the GPI Output pin
first, then click on Apply to GPI In. This will transfer the output
pin’s settings to the corresponding input pin.
39