I currently have a source (i.e. a POS system) connected to a ESC/P2 thermal printer via an RS232 serial connection. I wanted to place an arduino uno between the source and the thermal printer. Its main objective is to monitor what is sent to the printer and based on a condition (i.e. a flag, a certain string in the data, etc), it determines whether a print is required. I have a MAX232/RS232 DB9 shield to adjust the voltages, but i'm not sure if my source will be able to see my arduino as a printer and thus even allow a print job to occur.
The source is compatible with all ESC/P2 thermal printers.
EDIT: My questions are: 1) How do i configure my arduino to allow the source to print to it? 2) Can I hook up two RS232 connections to the arduino (one for input and the other for output)?