It might be because the machine is old. Hopefully, it does have the option to generate a CSV/ XML file. From the description, it does seem to have some kind of computer connected to it and a printer.

Otherwise, you might have to parse the data from the serial port.

Yea, I have to look into this, but even if it does do HL7, you need to write software to extract what you want and present it in a meaningful way to the other application.