Reading Data with usb serial port (Question)

[colocaps]

Hi! i have a scale for trucks, it is old, it has a serial port, im building a flutter program to comunicate with the scale. If i read data from it with a hyperTemrinal i end with data like this 'F00000' or '@102000' i thinks it is hexadecimal. But when i try to read with this package, i dont get nothing, with none of the functions. And the config is just like de hyperterminal, 8 bits, badrate 9600, no parity. Can you help me ??