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Part No. 920160 Rev A
February 1997
3.5.
FAULT REPORTING, continued
NNNNN.S Sale Money
PF.20.BB
Sale Volume
NNNNN:
Transaction Counter
S:
Side 1 or 2
P:
Product Source (0-7)
F:
Fault Source (0-7, “H” or “L”)
20:
Fault Code 20 (Jitter pulse logging error)
BB:
Maximum jitter count allowed
3.6.
INTRINSIC SAFE BARRIER ASSEMBLY
The Intrinsic Safe Barrier (ISB) assembly is located in the electronic head of the dispenser.
Its function is to ensure that the amount of electrical energy introduced into the hydraulics
cabinet is within acceptable limits. This barrier uses resistors, fuses, transistors and zener
diodes to limit energy out of the barrier. In the dispensing cycle, when the operating lever
is lifted, the nozzle switch moves to the closed position. This causes the nozzle signal on
the computer base to go from a +5 VDC potential to zero or ground potential, which alerts
the microprocessor to begin a new sale if the dispenser has been authorized and the push-
to-start, cash/credit or grade select switch has been pressed. In addition to the nozzle switch
circuits, the pulser selects are also protected by the ISB assembly.
The ISB circuit board
(
see Figure 3-6.
)
contains current limiting resistors and voltage
limiting redundant (2 in parallel) zener diodes which will limit voltage potential to approx-
imately 6.2 VDC. This energy limiting circuit eliminates the possibility of arcs in the
hydraulic area of the dispenser.
The ISB assembly is a sealed assembly and must be repaired at the factory. The ISB circuit
board in the assembly is not replaceable in the field. The complete assembly shown in
Figure 3-6. must be replaced if the ISB board becomes inoperative. See Section 7 for
replacement procedures.
Summary of Contents for Dresser Vista 1 Series
Page 1: ...1 Vista Series Blending and Non Blending Remote Dispensers SERVICE ...
Page 4: ...Part No 920160 Rev A February 1997 ...
Page 10: ...viii Part No 920160 Rev A February 1997 ...
Page 12: ...2 Part No 920160 Rev A February 1997 ...
Page 22: ...12 Part No 920160 Rev A February 1997 ...
Page 38: ...28 Part No 920160 Rev A February 1997 ...
Page 62: ...52 Part No 920160 Rev A February 1997 ...
Page 76: ...66 Part No 920160 Rev A February 1997 FIGURE 7 8 NOZZLE BOOT ASSEMBLY LIFT TO START ...
Page 77: ...67 February 1997 Part No 920160 Rev A FIGURE 7 9 NOZZLE BOOT ASSEMBLY PUSH TO START ...
Page 83: ...73 February 1997 Part No 920160 Rev A APPENDIX A TROUBLESHOOTING FLOWCHARTS ...
Page 110: ...100 Part No 920160 Rev A February 1997 ...
Page 111: ...101 February 1997 Part No 920160 Rev A APPENDIX B SERVICE INFORMATION AND CONNECTOR PIN OUTS ...
Page 134: ...124 Part No 920160 Rev A February 1997 ...
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