Troubleshooting Steps
Communication Issues - Checklist
Page 52 MDE-4318D Competitive Pump and CRIND (CPC) Hardware/Software Start-up and Service Manual · May 2010
3
If the issue persists, change the position back to normal operation and repeat this process on
the next fueling position.
If communication issues can be mitigated by isolating a unit from either the two-wire loop or
RS-485 loop, it indicates that the root cause exists outside the POS system. Further
investigation is required at the forecourt.
Outdoor Verification
What type of communication wiring is used?
Ensure that all communication wiring meets manufacturer’s specifications (solid core as
opposed to stranded, non-shielded as opposed to shielded, and so on). Wiring that does not
meet the manufacturer’s installation requirements may impede proper communication.
What is the distance from the farthest fueling position to the Distribution
Box?
Although two-wire can be run over a maximum of 1000 feet, RS-485 communication has a
maximum range of 800 feet. Since Wayne CATs use RS-485 communication to the Gilbarco
CPC distribution box, installations over 800 feet may compromise communication.
Is an intercom system in use? If so, do the intercom wires and dispenser
data wires in separate conduits?
Intercom wiring must not share the same conduit as communication wiring. Refer to the
manufacturer’s installation specifications for further details regarding wiring considerations.
Are other wires present in the conduit that contains the dispenser data
communication wires? If so, identify these wires.
Additional wiring, such as intercom wiring, must not share the same conduit as
communication wiring. Refer to the manufacturer’s installation specifications for further
details regarding wiring considerations.
What voltage is present when referencing ground (position 8 in the
Wayne junction box) to the junction box itself?
Note: This test must be performed at each unit.
No voltage (DC or AC) must be read at this point. If voltage is present here, there is a
grounding concern that may introduce noise into communication between the POS and
forecourt.
