Phmetro DM 22 with arduino

Need a little help to do a reading of a device straight to the arduino
the equipment is the pH meter dm 22 (photo attached equipment)

to link the equipment is made by the digital inputs of the arduino TX and RX to make your reading
however, I can not get any reading alert by analogRead ()
I set up the equipment for direct PC link or PRINTER

made the connection to the computer is performed by hyperterminal with windows XP

research that I conducted via the net are pHmeters SHIELDS however I need to be connected directly or if the equipment is not possible how can I do to pull data from hyperterminal connected to windows XP for ARDUINO.

Your explanation makes no sense. Is it a digitial or analog device ? What signal are you expecting to read from it ?

yes it is a digital device that sends the value obtained through a sensor attached to it, this value I need to read the arduino.