4 RS-232C communications4.2 Command listD-52/53/54/55 1014.2 Command listUse as the terminator for serialcommunication commands.All the commands (except the ON-LINE/OFF-LINEcommand) are valid only in the ON-LINE mode. (Anerror message is returned in the OFF-LINE mode.)The meter returns a response to any operation made inthe following format:OK>If the pH meter does not accept the operation, it returnsan error message in the following format:ER,nn=0: Communication error1: When a non-existent command is input.2: When a timing command is input to which the metercannot respond.3: When the numerical value in the command is out ofthe setting range.
