D4 Traffic Signal Controller

Feature Summary (Version 1.4o)

General Controller Features

• 16 phases
• Three maximum times per phase with dynamic max operation
• Minimum, maximum, soft recall modes
• Early and delayed “Walk” timing
• Conditional service during free and coordination, with conditional service minimum green time
• Manual control operation with selectable call, omit, and protected pedestrian clearance phases
• Per phase preempt timing
• 4 rings (Single intersection or two independent intersections)
• 16 timed overlaps
• Vehicle and pedestrian movement for each overlap
• Actuated pedestrian movements
• Early and delayed “Walk” timing
• Pedestrian overlap rest-in-walk across multiple phases
• Per overlap preempt timing
• 8 transit phases
• Two and three section signal head controls for light rail vehicles
• Advanced warning sign control per transit phase
• Recall or actuated operation
• Normal or priority service

Detector Features

• 64 vehicle detectors
• Programmable call and extend phases
• Extend and delay timing
• Stop bar disconnect mode with carryover (extend) timer
• Detector cross-switching
• No presence and max fail detector diagnostics (disabled by TOD)
• 16 queue detectors
• Detects traffic backups
• Capable of selecting alternate coordination patterns, selecting alternate maximum green times, or calling a preempt
• Advanced green to clear vehicle movements prior to transit vehicle arrival

• 16 pedestrian detectors
• Programmable calls for pedestrian and vehicle phases
• Pedestrian cascade mode (sequential calling of two pedestrian movements)
• 8 transit detectors
• Programmable calls for transit and vehicle phases
• Extend and delay timing
• Travel time delay
• Alternate travel times by TOD
• Adaptive arrival time adjustment
• 32 remote transit detectors
• Calls received by transit detectors at other intersections (on peer-to-peer Ethernet network)
• Travel time delay
• Alternate travel times by TOD
• Adaptive arrival time adjustment

Coordination Features

• 32 coordination patterns
• Cycle time and three offsets per pattern
• Flexible per phase split expansion and shrinking during transition
• Fixed or floating force-offs (per phase)
• Automatic permissive calculations
• Single-band or multi-band permissive modes with permissive limit timer
• Three pedestrian permissive modes
• Programmable recalls and omits active during each pattern
• Actuated coordinated phases can gap-out early and distribute unused time to movements with greater demand
• Selectable reservice phases (a.k.a. “fully actuated coordination”)
• Multiple interconnect modes
• Time based scheduler
• Central system command (over twisted pair or Ethernet connection)
• 120 volt interconnect cable
• Master controller mode
• Controller can operate as a twisted pair, Ethernet, or 120 volt cable master in the absence of a central management system

Preemption Features

• 10 prioritized preempts
• Two track clearance states, dwell state, and exit state per preempt
• Permit or allow any phase and overlap individually for each preempt state
• Presence preempt input with optional fail-safe interlock input
• “Check-in / Check-out” preempt detection option with check-out override timer

• 4 soft preempts
• “Step-by-step” preempt (special preempt sequence)
• 8 states per soft preempt sequence (timed or actuated)
• Each state allows programmable calls, omits, holds, and force-offs for each phase and overlap

Transit Priority Features

• Programmable transit priority options for each transit phase
• Operates based on estimated arrival times using local intersection detection and remote (“peer-to-peer”) detection from upstream intersections
• Separate options for free or coordinated operation
• Extend only (no phase abbreviation) or Early/Extend operation
• Minimum phase green times
• Maximum extend limit
• Optional vehicle/pedestrian phase omits
• Ability to switch to alternate sequence to better serve early arriving transit vehicle
• Adaptive arrival times to automatically compensate for fluctuating station dwell times

Status / Diagnostic Features

• Detailed controller status displays through the 2070 LCD display
• Phase, ring, and overlap status
• Transit phase/priority status
• Coordination status
• Preemption status
• Vehicle and pedestrian detector status
• Cabinet / Field I/O status
• System communication status
• 6000 controller event log
• Multiple classes of events can be individually enabled for logging
• Retrieved and reset from central connection (serial or Ethernet)
• 62.5 day detector VOS log
• Log VOS for 16 system detectors each 15 minutes
• 600 MMU event log
• Detailed MMU events, including reason for failure and state of field outputs 

Cabinet Support

• NEMA TS1, TS2-Type 1 and Type 2, Caltrans 332/336, and ITS cabinet support
• All controller input and output functions can be mapped to any physical cabinet input and output
• “Peer-to-Peer” interconnect over Ethernet (select outputs or inputs from the source intersection to activate a function at the local intersection)
• Cabinet logic channels to accomplish custom controller I/O operation

Protocol Support

• Communications over serial port, twisted pair, or Ethernet (fiber-optics)
• Caltrans AB3418E with extended messages for extended status and D4 specific functionality
• Future NTCIP compliance