new-logo
 
                              PUFFIN   PAGE 3/2
     SITE NAME MELROSE DRIVE NR LAWRENCE STREET   SITE NO. 6143
       
C. CLEARANCE EXTENSION FUNCTION  
     
  GENERAL        
         
  The Flashing Clearance display runs for a minimum time. This minimum time is specified in Special Purpose
  Timesetting No. 16. Activation of the CLEARANCE ZONE detectors (i.e. detectors 6 and/or 7, 8 & 9) provides 
  extension of the Flashing Clearance display up to a maximum time. This maximum time is specified in the  
  Clearance 1 Time of Pedestrian No. 1.      
         
  Between the minimum and maximum times as specified above, the Flashing Clearance display is terminated if the
  CLEARANCE ZONE detector has been vacated for the period as specified in Special Purpose Timesetting No. 13 
  (Note: generally set to 1 s).          
             
  ABNORMAL OPERATION          
         
  If the CLEARANCE ZONE detectors (i.e. detectors 6 and/or 7, 8 & 9) do not toggle ON during the Walk and through
  the Flashing Clearance interval up to the "STANDARD" clearance time, then terminate at this instant. The
  "STANDARD" clearance time is specified as the total of Special Purpose Timesetting No. 16 plus Special Purpose 
  Timesetting No. 17.          
     
  Note: When the controller is online to SCATS and a CLEARANCE ZONE detector does not toggle ON for
  the period as specified by the SCATS TDA message, then a Detector Alarm (DA) will be generated on that 
  CLEARANCE ZONE detector  
 
  If a CLEARANCE ZONE detector does not toggle OFF during the Walk and through the Flashing Clearance
  interval, then extend to maximum (i.e. Clearance 1 Time of Pedestrian No. 1). This may be due to a faulty detector,    
  or a large number of pedestrians.    
       
  Note: When the controller is on line to SCATS and a CLEARANCE ZONE detector does not toggle OFF
  for the period as specified by the SCATS TDA message, then a Detector Alarm (DA) will be generated on that
  CLEARANCE ZONE detector. If this occurs then the Flashing Clearance interval will terminate at the   
  "STANDARD" clearance time (i.e. the total of Special Purpose Timesetting No. 16 plus Special Purpose     
  Timesetting No. 17).    
     
3. OPERATION WITHOUT THE CLEARANCE ZONE DETECTORS BEING              
    USED FOR WALK EXTENSION      
     
  If it is decided that the pedestrians is to operate without the CLEARANCE ZONE detectors extending the
  walk, either or both of the following 2 methods can be used to allow this to occur.  
 
  Switch detector 10 to the ON position  
  Set XSF5 flag  
 
  In this situation the walk interval will be automatically set to the "STANDARD" walk time (i.e. the total of Special
  Purpose Timesetting No. 14 plus Special Purpose Timesetting No. 15).  
 
4. OPERATION WITHOUT THE CLEARANCE ZONE DETECTORS BEING
    USED FOR CLEARANCE EXTENSION  
 
  If it is decided that the pedestrians is to operate without the CLEARANCE ZONE detectors extending the
  clearance, either or both of the following 2 methods can be used to allow this to occur.  
 
  Switch detector 11 to the ON position  
  Set XSF6 flag  
 
  In this situation the clearance interval will be automatically set to the "STANDARD" clearance time (i.e. the  
  Special Purpose Timesetting No. 16 plus Special Purpose Timesetting No. 17).  
   
DESIGNED BY: JEREMY ERLICH           DATE 28/03/18