An incoming telephone call director is intended for use with a Ring-Master
service which provides different ring signals on a single telephone line
to selectively access one of several devices on the line. The call
director ignores a first ring, counts the pulses in the next ring, and
then directs the next subsequent ring to a selected telephone or device
such as a computer modem, facsimile, telex, etc., on the single telephone
line. A different sounding ring signal is used to identify and access each
telephone or device on an individual basis. The call director senses an
Off-Hook condition for the telephone or any one of the devices and
connects that device to the single telephone line to provide a Dial Tone
to permit a plurality of such devices to share a single telephone line
without interfering with each other or telephone calls on the line.
Although the first pulse is ignored for call routing purposes, the call
director converts this complete or partial high voltage pulse to power
itself in eliminating the requirement for line isolation or a battery
operated supply. A lockout circuit allows only one line at a time access,
while the system automatically begins waiting for the next call or for one
of the internal lines to go Off-Hook following completion of a call.