Commuincating with Laser Caliper (Laser Online LST-25 JIB)

Does anyone have experience in communicating with an LST - 25 JIB laser calibrator, Chinese brand Laser Online, with OPC Kepserver server through the MODBUS RTU protocol?

The Chinese brand LX-25 laser caliper has one RS485 serial port, and two synchronized ports. One synchronized port is connected to a programmer/display board, and the other to just a display board. Each display board shows in real-time the diameter (both x and y) of 3D printer filament passing through the laser.

I need to extract data from the measured diameter, which is shown on the screen of that calibrator. Could anyone give me a tip on how to extract this data? What adapter USB to RS 485 (Modbus RTU Serial) combines me to perform the extraction of reading this data?
RS-485 is a electronic specification for serial communication. As such, it does not define, recommend or imply any connection to the protocol, the set of rules determining how the serial communications operates, who talks, who listens, addressing, how data is formatted, whether to acknowledgement, errors and how to handle them, etc, etc, etc. RS-485 can handle any of thousands of serial protocols because all it does is carry bits back and forth, in a figurative sense. It doesn't care what the bits represent.

So that fact that there is an RS-485 port does not mean that the device communicates via the Modbus protocol. In fact, I'd be surprised if it does. If the device documentation does not mention Modbus, then it is highly unlikely that the device is capable of Modbus communications.

The device documentation might reveal what protocol the RS-485 port uses, but the serial communication to the display could very likely be a proprietary protocol.

If the vendor chooses to share details of their proprietary protocol then you can write code (or hire some to write code) to get data via the code. If not, you can 'sniff' the comm link and spend hours/days figuring out what the protocol is and then write code to get the data.

All anecdotal evidence points to the fact that it's easier to buy a device that provides the data you need via a standardized comm protocol than it is to crack/hack a proprietary protocol.