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the intersections to be assigned to a subsystem. Each Calculation <br /> Routine shall compute the volume and occupancy from selected <br /> detector input. Level Selection Routines shall be associated with <br /> the Calculation Routines to assign various programs, based on <br /> computed volume or occupancy. <br /> <br />Routines which shall be programmable by the operator shall be as <br />fol 1 ows: <br /> <br />(1) Time Interval Routines. It shall be possible for the operator to <br />select the start and'stop time for the day, hour, and minute in <br />which the Calculation Routine will become effective. Additionally, <br />the operator shall be able to assign up to 2 Calculation Routines <br />to each specific subsystem. As an alternative, it shall be <br />possible to preempt a particular program to control a subsystem <br />based on a selected time of day and day of week. <br /> <br />(2) Program functions which can be selected shall include, but not be <br /> limited to, cycle change, offset change, split change, coordinated <br /> or free operation and transfer control of intersections from one <br /> subsystem to another. The routine shall select one of the "daily" <br /> programs (or calculation routine) at the beginning of each day. <br /> Ten "daily" (or special event) programs shall be available for <br /> selection. <br /> <br /> This information shall be capable of being transmitted over a Bell <br /> System grade 3002 leased line between the two master controller <br /> locations. Daily programs may be preselected chronologically for 7 <br /> days before repeating in sequence. <br /> <br />(3) Calculation Routines. It shall be possible to program 128 each 12 <br /> detectbr Calculation Routines. The operator shall be able to <br /> select the average, highest, highest average, ratio, or a <br /> combination of these calculations of detector outputs, to compute <br /> volume and occupancy. Volume computations shall reflect the true <br /> volume in vehicles per hour per lane (V/HR/LN). An adjustable 100 <br /> percent level shall be progran~nable in a range from 0 through 1000 <br /> V/HR/LN in I V/HR/LN increments. In occupancy computations, it <br /> shall be possible to scale the true occupancy against a preselected <br /> 100 percent occupancy level. It shall be possible to select a <br /> transition (crossover) point at which the computer occupancy <br /> output, rather than the volume, shall become the controlling output <br /> of the Calculation Routine. Calculations shall be made after a <br /> progran~nable number of actuations are received or after a <br /> progran~able time, whichever occurs first. This shall allow the <br /> frequency of calculations to be proportional to traffic levels if <br /> desired. <br /> <br />(4) Level Selection Routines. 128 each Level Selection Routines <br /> assigned to a given sd~system shall be compared to these levels to <br /> select a subsystem program (Timing Pattern). <br /> <br />(5) Timing Pattern Routines. Up to 128 each Timing Patterns shall be <br /> available. Each 'Timing Pattern shall include a subsystem cycle <br /> <br /> -10- <br /> <br /> <br />