The OSD menu can be disabled from user interface easily.
Open the IE and connect to your Speed Dome via network.
Depends on your network board version there are two versions of interface, the same procedure applied.
Go to the pan-tilt panel, choose preset point number 95 then press GO button, you will see menu display on screen
Use UP and DOWN arrow to navigate
Use ZOOM+ to enter option
Use ZOOM- to escape one level
Inside the menu, you will find the options to disable baud rate parameter, etc.