The MC-780MA can communicate with the computer via USB A <> USB B cable (not included), and when TANITA PRO software is installed on the computer.

If the proper cable is used, and if the software is fully installed, and the communication doesn't work, this might be due to incorrect settings in the MC-780MA. 

Settings 30, 2 and 3 need to be set and saved on '0' (OFF), to put the MC-780MA in the correct state for communication with the computer.

Here is how to do this:

- Turn on the MC-780 and let it start up.

- When it is completely started, press the SETTING button.

- Go to setting 30 by entering the number '30' and confirm with 'ENTER'.

- Enter the number '0' and confirm with 'ENTER'.

- Now go to setting 2 by entering the number '2' and confirm with 'ENTER'

- Enter the number '0' and confirm with 'ENTER'

- Now go to setting 3 by entering the number '3' and confirm with 'ENTER'

- Enter the number '0' and confirm with 'ENTER'

- Press the SETTING button again to return to the start screen.