Specifies requirements for those characteristics of traffic signal controllers which interact with other equipment associated with road traffic signal installations, with the objective of ensuring that, as far as practicable, controllers from different manufacturers will be physically interchangeable, and that the functioning of the controller will be independent of the characteristics of externally connected equipment. It also specifies certain general requirements for the design and construction of controllers.
Table of contents
Header
About this publication
Preface
Foreword
1 Scope and general
1.1 Scope
1.2 Referenced documents
1.3 Definitions
1.4 General requirements
1.4.1 Ambient conditions
1.4.2 Atmospheric pollutants
1.4.2.1 General
1.4.2.2 Metallic parts
1.4.3 Power supply
1.4.3.1 Operating voltage
1.4.3.2 Surges on mains supply voltage
1.4.3.3 Breaks and brownouts in mains supply voltage
1.4.3.4 Insulation resistance
1.4.4 Shock and vibration
1.4.4.1 Shock
1.4.4.2 Vibration
1.4.5 Electromagnetic compatibility
1.4.5.1 General
1.4.5.2 Immunity to surges and electromagnetic radiation
1.4.5.3 Electromagnetic emissions
1.4.5.4 Lamp load configuration and cable length for testing
1.4.6 Weather resistance
1.4.7 Acoustic noise
1.4.8 Vandal resistance
1.4.9 Fire hazard
1.4.10 Electrical safety
1.4.11 Functional safety
1.4.12 Safety Case
1.5 Expansion capability
2 Controller housing
2.1 General
2.2 Physical requirements
2.3 Housing construction
2.3.1 General
2.3.2 Material
2.3.3 Mounting
2.3.4 Cable access and telecommunications conduit access
2.3.5 Door
2.3.6 Door hinges
2.3.7 Door locks
2.3.8 Door retainer
2.3.9 Weather sealing
2.3.10 Ventilation
2.3.11 Plan pocket
2.3.12 Equipment shelf
2.3.13 Finish and protection
2.3.14 Controller nameplate
2.3.15 Resistance to vandalism
2.3.16 Housing top extension
2.4 Cable clamping bars
2.4.1 General
2.4.2 Position
2.4.3 Clamping action and capacity
2.5 Switchboard
2.5.1 General
2.5.2 Mounting position
2.5.3 Main switch and fault current limiter
2.5.4 Lamps circuit breaker
2.5.5 Flash circuit breaker
2.5.6 Logic circuit breaker
2.5.7 Detector circuit breaker
2.5.8 Auxiliary circuit breaker
2.5.9 Socket-outlet with integral residual current device
2.5.10 Surge diverter
2.5.11 Order of switches on the switchboard
2.6 Field terminal blocks
2.6.1 Terminal types
2.6.2 Signal circuits
2.6.3 Lamp active and neutral
2.6.4 Detector active and neutral
2.6.5 External detector inputs and detector common
2.6.6 Loop terminations
2.7 Facility Switch and key
2.7.1 General
2.7.2 Switch positions and function
2.7.3 Type and rating
2.7.4 Mounting
2.7.5 Marking
2.7.6 Resistance to vandalism
2.7.7 Connection to the Site Identification Encoder (connector ZSW)
2.8 Master Relay and Auxiliary Relay
2.8.1 Function
2.8.2 Type and rating
2.8.3 Connection to the Site Identification Encoder (connector ZMR)
2.9 Flash Change-Over Relays
2.9.1 Function
2.9.2 Provision of Flash Change-Over Relays
2.9.3 Flash Change-Over Relay type and ratings
2.9.4 Selection of signal groups for flashing yellow
2.10 Miscellaneous relays and contactors
2.10.1 Function
2.10.2 Type and rating
2.11 Flasher Unit
2.11.1 Function and connections
2.11.2 Mains active supply to the Flasher Unit
2.11.3 Flasher Unit flashing active outputs
2.11.4 Prevention of residual direct current to the load
2.11.5 Lamp active sensing input
2.11.6 Disable flash inputs
2.11.7 Flash Change-Over Relay drive output
2.11.8 Flash Change-Over Relay status output
2.11.9 Flasher Unit control logic
2.11.10 ELV connector (XFC)
2.11.11 LV connector (XFP)
2.11.12 Earthing
2.11.13 Marking
2.11.14 Connection to the Site Identification Encoder (connector ZFL)
2.12 Site Identification Encoder
2.12.1 Drawings
2.12.2 Function
2.12.3 Site number
2.12.4 Master Relay and Auxiliary Relay connections (ZMR)
2.12.5 Facility Switch connections (ZSW)
2.12.6 Flasher Unit connections (ZFL)
2.12.7 Light sensor connections (ZLS)
2.12.8 Gas sensor connections (ZGS)
2.12.9 Housing door switch connections (ZDR)
2.12.10 Controller Logic Module connections (ZID)
2.12.11 Mounting, visibility and accessibility
2.13 Telecommunications interface
2.13.1 Conformance with ACMA standards
2.13.2 Transient voltage protection device
2.13.3 Telecommunications line terminal box
2.13.4 Cable and connector for PSTN modem connection
2.13.5 Instruction label
2.13.6 Telecommunications access conduit
2.14 Light sensor
2.14.1 Function
2.14.2 Type
2.14.3 Mounting
2.14.4 Connection to the Site Identification Encoder (connector ZLS)
2.15 Gas sensor
2.15.1 Function
2.15.2 Type
2.15.3 Sensing threshold
2.15.4 Gas sensor interface circuit
2.15.5 Mounting
2.15.6 Connection to the Site Identification Encoder (connector ZGS)
2.16 Housing door switch
2.16.1 Function
2.16.2 Mounting
2.16.3 Connection to the Site Identification Encoder (connector ZDR)
2.17 Extra low voltage (ELV) transformer
2.17.1 Function
2.17.2 Type, voltage and rating
2.17.3 Fusing and connections
2.18 Service light
2.19 Housing equipment layout
2.19.1 Mechanical arrangement
2.19.2 Shelf space
2.19.3 Blank panel space
2.20 Connectors
2.20.1 Interface connectors
2.20.2 Connector sensing and encoding
2.20.3 Connector coding or keying
2.20.4 Connector retention
2.21 Wiring
2.21.1 Safety Standards
2.21.2 Type and rating
2.21.3 Terminations
2.21.4 Marking and colour coding
2.21.5 Protection and mechanical support
2.21.6 Equi-potential bonding
2.22 Information to be provided in the housing
2.22.1 General
2.22.2 Danger sign
2.22.3 Housing layout diagram
2.22.4 Housing wiring diagram
2.22.5 Approval numbers
2.22.6 Housing serial number
2.23 Stand-by generator connection
2.23.1 General
2.23.2 Inlet for generator cable
2.23.3 Anchoring the generator to the controller housing
2.23.4 Connector for external generator
2.23.5 Power source change-over switch
2.23.6 Indication of presence of power
3 Controller Logic Module
3.1 General requirements
3.1.1 General requirements for design
3.1.2 System concept
3.1.3 Modular design
3.1.4 Site-specific adaptation of equipment
3.1.5 Safety
3.1.5.1 Failsafe principle
3.1.5.2 Fault mode
3.1.5.3 Conflict monitor system
3.1.5.4 Fallback signal displays
3.1.6 Reliability
3.1.7 Maintainability
3.1.8 Regulation and dimming of lamp supply voltage
3.2 System overview
3.2.1 System diagram
3.2.2 External devices summary
3.3 CPU module
3.3.1 Overview
3.3.2 Microprocessor
3.3.3 Program memory
3.3.4 RAM
3.3.5 CardBus interface
3.3.6 Configuration data memory
3.3.7 System data memory
3.3.8 Interrupt controller
3.3.9 Real time clock
3.3.10 Standby power source
3.3.11 Mains frequency clock
3.3.12 System clock
3.3.13 Hardware watchdog timer
3.3.13.1 Hardware watchdog timer implementation
3.3.13.2 Hardware watchdog timer expiry
3.3.13.3 System reset
3.3.13.4 Resetting the hardware watchdog timer
3.3.14 Hardware start-up timer
3.3.15 Master Relay control
3.3.16 Electronic identity
3.4 Interfaces
3.4.1 Overview
3.4.2 General requirements for protection
3.4.2.1 Protection against electrostatic discharge
3.4.2.2 Protection against surge voltages
3.4.2.3 Protection against mains voltage
3.4.2.4 Isolation
3.4.3 General requirements for design
3.4.3.1 Microcontroller circuits
3.4.3.2 Noise immunity
3.4.3.3 Measuring circuits
3.4.3.4 Interface connectors
3.4.3.5 Heatsinks
3.4.3.6 Electronic identities for interface modules
3.4.4 Signal group outputs
3.4.4.1 General
3.4.4.2 Interface requirements for signal group outputs
3.4.4.3 Overload protection
3.4.4.4 Prevention of half waving
3.4.4.5 Front panel indicators for signal group outputs
3.4.4.6 Connectors for signal group outputs
3.4.4.7 Coding for signal group output connectors
3.4.5 Pedestrian Wait Indicator outputs
3.4.5.1 General
3.4.5.2 Interface requirements for Wait Indicator outputs
3.4.5.3 Connector for pedestrian Wait Indicator outputs
3.4.6 Integral detectors
3.4.6.1 General
3.4.6.2 Interface requirements for integral detectors
3.4.6.3 Connectors for detector loops
3.4.6.4 Coding for detector loop connectors
3.4.7 External detectors and pushbutton inputs
3.4.7.1 General
3.4.7.2 Interface requirements for detector and pushbutton inputs
3.4.7.3 Front panel control switches for detector and pushbutton inputs
3.4.7.4 Front panel indicators for detector and pushbutton inputs
3.4.7.5 Connectors for detector and pushbutton inputs
3.4.7.6 Coding for detector and pushbutton inputs connectors
3.4.8 Special Facility inputs and outputs
3.4.8.1 General
3.4.8.2 Interface requirements for Special Facility inputs
3.4.8.3 Interface requirements for Special Facility outputs
3.4.8.4 Front panel indicators for Special Facility inputs and outputs
3.4.8.5 Connectors for Special Facility inputs and outputs
3.4.8.6 Coding for Special Facilities connectors
3.4.9 Daily Event output
3.4.9.1 General
3.4.9.2 Interface requirements for Daily Event output
3.4.9.3 Connector for Daily Event output
3.4.10 Site Identification Encoder
3.4.10.1 General
3.4.10.2 Site ID bus
3.4.10.3 Site ID bus addresses
3.4.10.4 Connector for Site Identification Encoder
3.4.11 Master Relay interface
3.4.11.1 General
3.4.11.2 Interface requirements for the Master Relay
3.4.11.3 Monitoring of switches
3.4.12 Auxiliary Relay interface
3.4.12.1 General
3.4.12.2 Interface requirements for the Auxiliary Relay
3.4.13 Facility Switch interface
3.4.13.1 General
3.4.13.2 Requirements
3.4.14 Flasher Unit interface
3.4.14.1 General
3.4.14.2 Interface requirements for the flash disable output
3.4.14.3 Interface requirements for the Flash Change-Over Relay status input
3.4.14.4 Interface requirements for residual d.c. fault input
3.4.15 Housing door switch interface
3.4.15.1 General
3.4.16 Light sensor interface
3.4.16.1 General
3.4.16.2 Interface requirements for the light sensor
3.4.17 Gas sensor interface
3.4.18 Serial communications interface to master computer
3.4.18.1 General
3.4.18.2 Interface requirements for internal modem
3.4.18.3 Interface requirements for stand-alone modem
3.4.18.4 Loop-back switch
3.4.18.5 Front panel indicators
3.4.18.6 Connector XM for communications to a master computer
3.4.19 Serial communications to portable terminal
3.4.19.1 General
3.4.19.2 Interface requirements for portable terminal (TTY) serial port
3.4.19.3 Connector for portable terminal
3.4.20 Serial communications to hand held terminal
3.4.20.1 General
3.4.20.2 Interface requirements for HHT serial port
3.4.20.3 Connector for hand held terminal
3.4.21 Serial ports for intelligent transport systems
3.4.21.1 General
3.4.21.2 Interface requirements for ITS serial ports
3.4.21.3 Connectors for ITS devices
3.4.22 Front panel switches
3.4.22.1 General
3.4.22.2 Implementation
3.4.23 Front panel indicators
3.4.23.1 General
3.4.23.2 Implementation
3.4.24 Measuring system
3.4.24.1 General
3.4.24.2 Requirements for measurements
3.5 Conflict monitor system
3.6 Power supplies
3.6.1 Overview
3.6.2 Direct current supplies
3.6.3 Power supply failure detection and low mains indication
3.6.4 Monitoring of supply rails
3.6.5 Connector for power supply (XP)
3.7 Logic module
3.7.1 Overview
3.7.2 Logic Module dimensions
3.7.3 Logic Module arrangement
3.7.4 Logic Module weight
3.7.5 Retention of modules
4 Software and functional requirements
4.1 General requirements
4.1.1 Scope of requirements
4.2 Controller operation
4.2.1 General requirements
4.2.2 Phases
4.2.3 Phase intervals
4.2.3.1 General
4.2.3.2 Late Start
4.2.3.3 Minimum Green
4.2.3.4 Variable Initial Green
4.2.3.5 Rest Green
4.2.3.6 Extension Green
4.2.3.7 Early Cut-Off Green
4.2.3.8 Early Cut-Off Yellow
4.2.3.9 Yellow
4.2.3.10 All Red
4.2.4 Phase demands
4.2.4.1 General requirements
4.2.4.2 Vehicle detector actuations
4.2.4.3 Vehicle detector presence timers
4.2.4.4 Reversion demands
4.2.4.5 Pedestrian movement demands
4.2.4.6 Arterial demands
4.2.4.7 Logic flags
4.2.4.8 Condition table demands
4.2.4.9 External inputs
4.2.5 Extending a phase
4.2.6 Pedestrian movements
4.2.6.1 General requirements
4.2.6.2 Don’t Walk
4.2.6.3 Delay1
4.2.6.4 Delay2
4.2.6.5 Walk1
4.2.6.6 Walk2
4.2.6.7 Clearance1
4.2.6.8 Clearance2
4.2.7 Pedestrian demands
4.2.8 Safety interlocks
4.2.9 Vehicle signal groups
4.2.10 Pedestrian signal groups
4.2.11 Controller operating modes
4.2.11.1 General requirements
4.2.11.2 Isolated mode
4.2.11.3 Flexilink-Isolated mode
4.2.11.4 Flexilink mode
4.2.11.5 Masterlink mode (SCATS only)
4.2.11.6 Pre-emption mode
4.2.11.7 Fault mode
4.2.11.8 Site Diagnostic mode
4.2.12 Detector functions
4.2.12.1 General requirements
4.2.12.2 Presence timers
4.2.12.3 Five-minute counts
4.2.12.4 Volume and non-occupancy data (SCATS only)
4.2.12.5 Volume and occupancy data (Streams only)
4.2.12.6 Chattering detector alarms
4.2.12.7 Detector alarms (SCATS only)
4.2.12.8 Detector alarms (Streams only)
4.2.12.9 Pushbutton alarms
4.2.13 Special Facility controls
4.2.13.1 General requirements
4.2.13.2 Special Facility alarms
4.2.14 Controller clock
4.2.15 Controller log
4.2.16 Controller start-up
4.3 Interface to a coordination master
4.3.1 General requirements
4.3.2 Communications channel
4.3.3 Control
4.3.4 Monitoring
4.3.5 Transfer of operational data
4.3.6 Data collection
4.3.7 Inventory
4.3.8 ITS applications
4.3.9 Alarms
4.3.10 Remote user interface
4.3.11 Diagnostics and miscellaneous functions
4.4 Interface to controller hardware
4.4.1 General requirements
4.4.2 Signal group outputs
4.4.3 Pedestrian Wait Indicator outputs
4.4.4 Detector and pushbutton inputs
4.4.5 Special Facility inputs and outputs
4.4.6 Daily Event output
4.4.7 Site Identification Encoder
4.4.8 Master Relay and Auxiliary Relay
4.4.9 Facility Switch
4.4.10 Flasher Unit
4.4.11 Housing door switch
4.4.12 Light sensor
4.4.13 Gas sensor
4.4.14 Modem port
4.4.15 Portable terminal (TTY) port
4.4.16 User interface (HHT) port
4.4.17 ITS ports
4.5 Safety functions
4.5.1 General requirements
4.5.2 Check for mating of connectors
4.5.3 Check program memory
4.5.4 Check Personality data
4.5.4.1 Checksum check
4.5.4.2 Integrity check
4.5.5 Check timesettings and Flexilink data
4.5.5.1 Checksum check
4.5.5.2 Integrity check
4.5.6 Check on execution time for software
4.6 Conflict monitor system
4.6.1 General requirements
4.6.2 Response to a fault condition
4.6.3 Response to an error condition
4.6.4 Signal group measurements
4.6.4.1 Check for absence of measurements
4.6.4.2 Consistency check for measurements
4.6.4.3 Measurements for green and yellow aspects
4.6.4.4 Measurements for red aspects
4.6.5 Conflict monitor process
4.6.5.1 Response time
4.6.5.2 Confirmation of fault conditions
4.6.5.3 Drive-feedback checks
4.6.5.4 Conflict checks
4.6.5.5 Intergreen conflict checks
4.6.5.6 Critical red checks
4.6.5.7 Valid display checks
4.6.5.8 Response to particular fault conditions
4.6.5.9 Spurious conflict conditions
4.6.5.10 Self check process
4.6.6 Prevention of confusing displays
4.7 Lamp monitoring
4.7.1 General requirements
4.7.2 Measurement of lamp supply voltage
4.7.3 Signal group power measurements
4.7.4 Algorithm for learning signal group loads
4.7.5 Algorithm for detecting and reporting lamp faults
4.8 HHT user interface
4.8.1 General requirements
4.8.2 Display/Change operational data
4.8.3 Monitor controller operation
4.8.4 Apply overrides to the controller operation
4.8.5 Monitor detector alarms
4.8.6 Monitor signal group functions
4.8.7 Display inventory data
4.8.8 Display Personality data
4.8.9 Display/change configuration parameters for hardware
4.8.10 Miscellaneous commands
4.8.11 Diagnostic commands
4.8.12 Site diagnostic tests
4.9 Configuration data
4.9.1 General requirements
4.9.2 Timesettings data
4.9.3 Flexilink data
4.9.3.1 General requirements
4.9.3.2 Schedule data (SCATS only)
4.9.3.3 Schedule data (Streams only)
4.9.3.4 Plan data
4.9.4 Personality data
4.9.4.1 General requirements
4.9.4.2 Identity
4.9.4.3 Dimensional constants
4.9.4.4 Phase related data
4.9.4.5 Vehicle signal group displays
4.9.4.6 Pedestrian movements
4.9.4.7 Conflict data
4.9.4.8 Detector data
4.9.4.9 Priority demands
4.9.4.10 Flexilink data
4.9.4.11 Miscellaneous
4.10 Software updates
4.10.1 Control program
4.10.2 Configuration Data
Appendix A
Appendix B
B1 General
B2 Text string data
B2.1 Type or model number and hardware revision
B2.2 Serial number
B2.3 Firmware revision
B3 Numerical data
B3.1 Type or model number and hardware revision
B3.2 Serial number
B3.3 Firmware revision
Appendix C
C1 XA, XB, XC, XD, XAA, XBB, XCC, XDD signal group outputs
C2 XDY pedestrian Wait Indicator outputs and Daily Event output
C3 XEA, XEB, XEC, XED external detector and pushbutton inputs
C4 XHHT hand held terminal
C5 XID Site Identification Encoder
C6 XLD, XLL detector loops 1–32
C7 XM communications port to master computer
C8 XP Logic Module power connector
C9 XSF special facility inputs and outputs 1–12
C10 XTSA, XTSB intelligent transport systems ports 1–2
C11 XTSC, XTSD intelligent transport systems ports 3–4
C12 XTTY portable terminal
C13 XXF special facility inputs and outputs 13–24
Appendix D
D1 XFC Flasher Unit control
D2 XFP Flasher Unit power
Appendix E
E1 ZDR door switch
E2 ZFL Flasher Unit
E3 ZGS gas sensor
E4 ZID Logic Module
E5 ZLS light sensor
E6 ZMR Master Relay
E7 ZSW Facility Switch
Appendix F
F1 Connectors XA, XB, XC, XD, XAA, XBB, XCC, XDD
F2 Connector XP
F3 Connector XFP
F4 Site Identification Encoder connectors
Appendix G
G1 Scope
G2 General overview of a safety case
G3 Hazards
G3.1 General
G3.2 Hazard H1—A rigid object adjacent to a roadway
G3.3 Hazard H2—Sharp projections on the equipment
G3.4 Hazard H3—Electrically live metal
G3.5 Hazard H4—Accumulation of gas in the equipment
G3.6 Hazard H5—A source of combustion
G3.7 Hazard H6—A source of Electromagnetic Interference
G3.8 Hazard H7—No signal indications (i.e. blacked-out signals)
G3.9 Hazard H8—Conflicting signal indications
G3.10 Hazard H9—Conflicts arising from timing relationships for signal displays
G3.11 Hazard H10—Formation of traffic queues (eg on approaches with rail crossings, or motorway exits)
