Please check if the communication setting of WinCT matches the balance in use (baud rate, parity, bit length, stop bit, terminator).
Is the connection made to the correct COM port on the computer? Please use Device Manager to confirm the port on the computer.
Are you using the correct cable? (Please click here for more information:"What cable should I use to connect my computer and balance?")
Are you using a balance made by A&D? We don’t guarantee for operations of products made by any manufacturer other than A&D.