GENERAL NOTES
SUMMARY OF XSF FLAGS
XSF5 - Inhibits Clearance Zone detectors from extending the walk.
XSF6 - Inhibits Clearance Zone detectors from extending the clearance.
XSF9 - For queuing feature use (Refer to Page 6).
XSF10 - For queuing feature use (Refer to Page 6).
SUMMARY OF MSS FLAGS
MSS11 - Set for the duration of P1 demand.
GENERAL OPERATION
1. Expire AØ ECO if going AØ®BØ, AØ®DØ and AØ®EØ.
2. Expire DØ ECO if going DØ®EØ.
SIGNAL GROUP OPERATION
SIGNAL GROUP 1 & SIGNAL GROUP 2
VA Mode
1. SG1 and SG2 close down at the start of AØ yellow.
Masterlink and Flexilink
1. If going AØ®CØ or AØ®FØ with a demand for P1, SG1 and SG2 close down at the start of AØ    
    yellow.
2. If SG1 and SG2 gap, waste or go to maximum in BØ with a demand for P1, start Timer 1 (Refer to  
    AØ ECO) when Timer 1 expires, SG1 and SG2 close down.  Timer 1 reset at the start of SG1 green.
3. If going DØ®FØ with a demand for P1, SG1 and SG2 close down at the start of DØ yellow.
4. If SG1 and SG2 gap, waste or go to maximum in EØ with a demand for P1, start Timer 1 (Refer to 
    AØ ECO). When Timer 1 expires, SG1 and SG2 close down. Timer 1 is reset at the start of SG1  
    green.
OPERATION OF “PREPARE TO STOP” SIGN
1. Relay Output 1 controls the operation of a flashing alternating “PREPARE TO STOP”/BLANK sign.  
    (Note: BLANK refers to sign showing no display)
2. Relay Output 1 is activated by P4 Wait State (ATSC4/PSC2000/QTC) or by Special Output 1 
   (Eclipse). 
3. Both P4 Wait State (P4WS) and Special Output 1 (SO1) are set in the controller personality.
4. P4WS can be monitored by keying in A.E03BD (PSC2000) or 7 (Diag) > 1 (Mem) > 3BD (Alpha 16/ 
    ATSC4/ QTC) into the controller, or in SCATS Access, Show > Controller > Memory - Page 3, Offset 
    BD (Hex).
5. SO1 can be monitored by keying in 7 (Diag) > 1 (Mem) > 37A (Eclipse) into the controller, or in
    SCATS Access, Show > Controller > Memory - Page 3, Offset 7A (Hex).
VA Mode:
Relay Output 1 is switched on at the start of AØ ECO and remains on until one of the following conditions is first met:
1.             Timer 2 (refer Special Purpose Timesetting No. 9) expires. Timer 2 starts timing at the start of SG1 green. Timer 2 is reset at the start of SG1 green (Note Timer 2 should be equal to or less than SG1 minimum green).
2.             Detectors 1 and 2 become unoccupied for a period specified in Special Purpose Timesetting No. 20 (gap time) during the east approach green period.
Masterlink and Flexilink:
If going AØ®CØ or AØ®FØ with a demand for P1, Relay Output 1 is switched on at the start of AØ ECO. If going DØ®FØ with a demand for P1, Relay Output 1 is switched on at the start of DØ ECO. 
If going BØ®CØ or BØ®FØ or EØ®FØ with a demand for P1, Relay Output 1 is switched on when SG1 & SG2 gap, waste or go to maximum.
Relay Output 1 remains on until one of the followings conditions is first met.
1.                  Timer 2 (refer Special Purpose Timesetting No. 9) expires.  Timer 2 starts timing at the start of SG1 green.  Timer 2 is reset at the start of SG1 green (Note Timer 2 should be equal to or less than SG1 minimum green).
2.                  Detectors 1 and 2 become unoccupied for a period specified in Special Purpose Timesetting No. 20 (gap time) during the east approach green period.
Calculation of ECO
ECO = Time to travel from the sign to the stopline (147/16.67 m/s = 8.8) – time to travel from the nominal stopping distance to the stopline (phase yellow = 4.0) + reaction time, including time to travel the viewing distance (1.5s) 
         = 8.8 – 4 + 1.5
         = 6.3 (6.0s)