


        The RS232 option consists of hardware and software to be 
        installed in the FONIX FA1x audiometer. It also includes the 
        RS232 cable, and an IBM PC format floppy disk containing the 
        documentation, MSDOS device drivers, sample programs, and 
        diagnostics which run on the IBM PC.

        The RS232 option allows the computer to receive data from the 
        audiometer and to control the audiometer operation. 

        Information can be retrieved from the audiometer as either ASCII 
        data streams, or via the Frye Instrument Packet Protocol. The 
        audiometwer can be controlled via the Frye Instrument Packet 
        Protocol only (for reliability reasons). 

        All control positions on the audiometer front panel can be read 
        at any time through the RS232 interface. A 32 step buffer is 
        provided to prevent lost data should the computer not be able to 
        read the panel before the next change occurs. (The buffer is
        16 steps in V1.10 software.)

        The functionality of the audiometer is enhanced when it is 
        switched to operate under computer control. The frequency can be 
        set to any value rather than being limited to the frequencies 
        available on the panel switch. The level can be controlled in 
        0.1dB steps rather than the 2.5dB steps available from the front 
        panel. The audiometer also becomes a full two channel audiometer 
        when under computer control. The left and right channels are 
        individually controlled, including seperate frequency control in 
        each channel. Operation of the audiometer when under computer 
        control is via a virtual control panel accessed via the RS232 
        interface. 

        We supply full documentation for the protocol used by the 
        audiometer on the disk. Along with the documentation we supply a 
        device driver which will run on any IBM PC or true compatible 
        computer and an extensive set of sample programs. The sample 
        programs are written in Pascal. The full source code for the 
        programs is provided. 

        The documentation supplied in the disk is mainly targeted at 
        programmers who will be implementing software to link the 
        audiometer to a computer.















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