1. An interactive security system for controlling access, comprising: conditional state means for cycling through a sequence of logic states with a first logic state varying as a function of the present state of said conditional state means, said conditional state means having an input for receiving control signals, at least one output and monitoring means for evaluating the condition of said at least one output and a conductor connected thereto; means for applying control signals to said input and for receiving signal information from said at least one output; said means for applying responsive to signal information of one condition from said output to apply a first logic level to said conductor connected to said at least one output and apply additional control signals to said input and responsive to signal information of another condition to apply additional control signals to said input, said monitor means acting in the presence of said first logic level to place said conditional state means in an initial condition to cause a sequence of logic states to be read in response to said control signals; means for storing a predetermined state signal; means for comparing; means for establishing bi-directional communication between said conditional state means and said means for comparing, said conditional state means being removable from said bi-directional communication means, said means for comparing receiving a state signal produced from said removable conditional state means, comparing said produced state signal to said stored predetermined state signal, and enabling access in response to the production of a proper sequence of logic states as indicated by said comparison of said produced state signal to said stored state signal.