Supervisory control and communications system

Claim 1

IN A SUPERVISORY SYSTEM INCLUDING AT LEAST A FIRST AND A SECOND STATION CONNECTED OVER A COMMUNICATION CHANNEL, A PLURALITY OF FUNCTIONAL UNITS DIVIDED INTO GROUPS AND POINTS IN A GROUP, EACH GROUP OF POINTS BEING PREASSIGNED A DIFFERENT GROUP SELECTION CODE SIGNAL, AND EACH POINT IN A GROUP BEING ASSIGNED A DIFFERENT POINT SELECTION CODE SIGNAL, EACH CODE SIGNAL BEING OF A SELF-CHECKING CODE IN WHICH EACH SIGNAL IS COMPRISED OF A GROUP OF SIX PULSES EACH OF WHICH IS COMPRISED OF A MARKING AND SPACING ELEMENT, CERTAIN OF THE SPACES LESS THAN THE TOTAL SPACES IN THE CODE BEING ELONGATED, THE POSITION OF THE ELONGATED SPACES BEING VARIED TO PROVIDE DIFFERENT CODES; SIGNAL GENERATOR MEANS AT SAID FIRST STATION, AT LEAST, FOR GENERATING IMPULSES, CONTROL MEANS FOR CONTROLLING THE NUMBER OF MARKS AND SPACES GENERATED FOR EACH CODE SIGNAL BY SAID SIGNAL GENERATOR MEANS, AND SELECTION MEANS AT ONE POINT AT LEAST INCLUDING A FIRST MEANS OPERATIVE TO ENABLE SAID CONTROL MEANS TO EFFECT THE GENERATION OF A GROUP SELECTION CODE OF SIX IMPULSES INCLUDING A FIRST AND A SECOND ELONGATED SPACE AT THE POINT ASSIGNED TO THE CODE FOR THE GROUP OF POINTS WHICH INCLUDES SAID POINT, AND A SECOND MEANS AT SAID POINT OPERATIVELY CONTROLLED BY SAID FIRST MEANS RESPONSIVE TO COMPLETE TRANSMISSION OF SAID GROUP SELECTION CODE TO ENABLE SAID CONTROL MEANS TO EFFECT THE GENERATION BY SAID SIGNAL GENERATOR MEANS OF A POINT SELECTION CODE SIGNAL HAVING SIX IMPULSES INCLUDING A FIRST AND A SECOND ELONGATED SPACE AT THE POSITIONS ASSIGNED TO THE CODE SIGNAL FOR THE POINT.