MDE-4319A TopKAT Fuel Managment System Installation Manual · November 2005
Page 17
Communication Requirements
General Installation
Communication Requirements
The TopKAT utilizes RS-485, RS-232, and RS-422 modes of communication for
communicating to the ASTRA, 9800, Mechanical PCUs and peripheral equipment. The
TopKAT has three ports. Port 1 is an RS-485 port which is dedicated to communicating with
the ASTRA or satellite TopKAT. Ports 2 and 3 are configurable for either RS-232 or RS-422
for communications to a data terminal, modem, or PC. Phone line (modem) communication
may also be used when remote communication to the site is desired. In cases where a TopKAT
internal modem is used, port 3 is not available for external communication wiring. The
specific requirements for each of these modes of communication are listed below.
RS-485 - ASTRA and Mechanical PCUs
RS-485 wiring is used for communication between the TopKAT, ASTRA, and Mechanical
PCUs. This communication takes place over RS-485 wiring, which is supplied with the
TopKAT.
RS-485 - Master/Satellite Option
The master/satellite option uses two wires to operate a half-duplex RS-485 communication
loop. Ports 2 and 3 of the master can be set for either RS-232 or RS-422 communications to a
data terminal or computer or used to communicate with an optional built-in modem.
1
All wiring is to be installed and used in accordance with all building/fire codes, all Federal,
State, and Local codes, National Electrical Code (NFPA 70), NFPA 30, and Automotive and
Marine Service Station Code (NFPA 30A) codes and regulations. Wiring must also conform
to the wiring diagram supplied with the pump/remote remote dispenser. Canadian users must
also comply with the Canadian Electrical Code.
2
Power: The AC power for the short haul modem should come from the same breaker that
supplies the peripheral device or the system (Micro Feed).
3
Cable: Twisted pair shielded cable is highly recommended for RS-485 wiring. Although it is
recommended that wires be run in a conduit separate from AC wires, they can be combined in
the same conduit with AC wires providing UL-Listed cable with the following specifications
is used:
• Conductor: 18 AWG stranded wire. 1 twisted-pair.
• Shield: Foil-wrapped 100% coverage and/or tinned copper braid 90% coverage
• Drain Wire: Stranded, tinned copper, 20 AWG or larger/or braided shield
• Voltage Rating: Maximum operating voltage of 600V
• Environmental: Gas- and oil-resistant; suitable for wet or dry locations.
Gasboy can supply Belden 1120A (P/N C09672) which is a UL-Listed, 2-conductor cable that
meets the requirements listed above.
Note: Belden 1120A is UL-Listed but not CSA listed.
Cable with a voltage rating of less than 600V must be installed in a conduit separate from all
AC wires.
4
Conduit: When using the recommended shielded twisted-pair cable, RS-485 wires can be run
