The unit will return “#” when @ is sent. This can be used to establish communication between the computer and the unit. One application for this command is a software setup routine that automatically searches for the unit by sending an @ character on each COM port and IRQ until a “#” is returned. The corresponding COM port and IRQ number then can be set automatically by the application.

This command returns the firmware version, all toggle values, line number of the first channel, and date & time (in 24 hour format) on the internal time clock. On start-up the date & time will be set to zero. All toggles are stored in non-volatile memory and will remain saved even if the unit loses power. The internal clock does not run while the unit is off, and therefore, it must be set when power is restored. The clock can be set by the software using the "Z" command and will be set on the first good Caller ID signal. Subsequent Caller ID signals with good checksums will continue to reset the internal time clock with the telephone company’s time.

This command resets the operating system and resets all toggles to their default values. It does not reset the internal clock. The time clock can be reset by using the "Zmmddhhmm" command discussed in the next section or by capturing a good Caller ID signal.