Subscriber inventory network

Claim 1

A subscriber inventory network for selectively disseminating messages to receiving units of one or more subscriber groups comprising: a central message generator and transmitter for transmitting coded messages, each message including an initializer bit, a plurality of command bits, a plurality of group address bits, a plurality of unit address bits, and a plurality of message data bits, with each command bit and address bit having a first logic state and a second logic state; at least one receiver in each group being responsive to said coded messages transmitted by said central message generator, each receiver including means for responding to command bits in said message from said transmitter received by said receiver; each of said receivers having a pre-programmed group code identifier and a pre-programmed unit address identifier; and each of said receivers including a message controller for receiving the message bits and for selectively communicating the message bits to a single unit of a single group, all units of a single group, or all units of all groups according to logic values associated with said command bits, respectively; wherein said command bits include a group/unit distribution bit and an all group/single group flash command bit, said distribution command bit and said flash command bit being applied to first and second D flip-flops, respectively, with the distribution flip-flop being actuated by the initializer bit, and with the flash command flip-flop being actuated by the Q output of said distribution flip-flop; the data output Q of the distribution flip-flop providing an enabling signal for the flash command flip-flop, and the complementary data output Q0 of the distribution flip-flop providing an enabling signal for enabling a single receiving unit; the data output Q of the flash command flip-flop providing an enabling signal for all units/all groups, and the complementary data output Q0 of the flash command flip-flop providing an enabling signal for all units in a single group; the data output Q of the distribution command flip-flop being combined with the complementary data output Q0 of the flash command flip-flop in a first AND gate, thereby producing a conditional enabling signal for all units in a single group; and the data output Q of the distribution command flip-flop being combined with the data output Q of the flash command flip-flop in a second AND date for producing a conditional enabling signal for all units and all groups when both data output Q signals of the distribution command flip-flop and the flash command flip-flop are logic high.