Serial output from M800

[tet]

Hi all,
Currently I'm trying to connect third party lcd to Motec.
To do that, Motec rs232 TX had been connected to RX on the computer and ground is shared.

Clearly the data stream was detected and logged on the PC, while comstruction seems to be wrong.
Due to the M800 dataset 3 protcol pdf, header should be 82,81,80 and there are 175 bytes for a cycle but the data starts from 00, there are only 82,81 on some address but no 80 following them. More worse, a cycle seems to be constructed with around 520bytes (/cycle)
Baud rate is set to 19201 on Motec, 19200 on PC.
Bit is set to 8, start bit to 1 on PC.

Do you have any idea for that.
I'm keen and being little hurry for getting correct data.

Thanks for your attention on my board.

Kind Regards.