RES 87202 - Laserfiche WebLink

acoustic coupler used with a standard telephone handset shall be available, to provide the capability of interfacing for data transmission and control capabilities between the remote operator and the master computer. c. A digital multiplexing system shall provide communications between the. system master and all local controller and surveillance assemblies. The system shall be capable of handling all command and data requirements for 4 intersection controllers and/or surveillance units on one pair of interconnect conductors. The transmission of voice communication between each local intersection controller and the system master shall require no more than 1 pair of interconnect conductors for each 4 controllers. The master multi pl ex ci rcui try mounted i n the master control consol e shall transmit and receive all signals to and from the local intersection controllers and the surveillance assemblies (sampling detector stations). The multiplex equipment shall be capable of operating over a Bell System 3002 Grade circuit or up to 10 miles of 19 awg twisted pair conductors in REA specification PE-Z2 cable (with line amplifiers as requi red ). d. The master intersection display shall consist of a colorgraphic CRT terminal (13-inch or larger diagonal measurement). The master intersection display shall provide visual indication of vehicle calls, pedestrian calls and intersection activity (red signal, green signal., flash and pedestrian status) of any selected intersection of those intersections under the control movements of the master. Up to 8 vehicle movements and up to 4 pedestrian movements shall be displayed. The intersection display shall be based on local intersection feedback and not master command. Additionally, intersection and subsystem operation display shall be provided. Communication status, loss of signal, alarm, flash feedback standby and a visible indication of time displacement fran the subsystem synchronization time in seconds shall be indicated for each intersection selected for display on the Master Intersection Display. A readout shall be provided for the date, time, cycle length, split, offset, and the number of the intersection selected for display. The intersection to be displayed shall be selectable directly with controls on the Master Intersection Disp.lay. e. An output circuit shall be provided to operate a remote alarm light on the wall-mounted display map, in parallel with th.e alarm on the master. f. Disc memory may be used for on-line data and program 'storage. In the event that the computer memory is volatile, the operating program shall be automatically loaded into the compute when power is restored after a power loss. -4-