4.4 Communications
VST Fuel S-810 systems are designed to interface to serial communication devices. Generally the serial device is a
printer, a modem, or a personal computer. Connection to these devices are at the removable terminal strip
on the RS 232 or RS 485 boards mounted on the MotherBoard inside the VT-Fuel 810
(See Figure 15). Low voltage wiring is used to make these connections. A communications grade of shielded cable
suitable for RS 232 or RS 485 is recommended (#24 AWG minimum, twisted pair, low capacitance). Be
sure to ground the shield at one end only.
The following figures (Figures 9-14) show typical installation connections for several devices. Specific devices may
require jumpers on some of the control signals that are not required for the operation of the VST Fuel
S-810. Usually connecting the communication device's DTR signal back to the DSR, DCD, and CTS
signals will satisfy any protocol requirements for printers and personal computers. Modems need to be
configured in the answer mode with the appropriate baud rate. The configuration should be stored as the
default mode of the modem on power up to insure that it will operate without intervention. Figure 12 shows
the minimum field wiring required for a modem. The additional control signals (CTS, DCD, RTS, and
DTR) may be connected on a one-for-one basis if desired (See Figure 13). The support of these signals is
limited to providing the correct signal level for operation of the modem.
WARNING:
L
OOSE CABLES
,
OR CABLES ROUTED ON FLOORS OR PASSAGE AREAS
,
CREATE HAZARDOUS CONDITIONS TO PERSONNEL
AND POSSIBLE DAMAGE TO EQUIPMENT
. P
ROPERLY SECURE ALL CABLING TO FLAT SURFACES
,
SUCH AS
WALLS
OR
TABLE
SIDES
TO
AVOID
PERSONAL
INJURY
,
PROPERTY
LOSS
,
AND
EQUIPMENT
DAMAGE
5. VST FUEL S-810 WIRING VERIFICATION
5.1 General
In order to verify the wiring it is convenient to have the VST Fuel S-810 operational (ac power applied) and be
familiar with some of the basic built-in diagnostic tools. This section is a brief explanation of the built-in
diagnostics. These diagnostics may vary for specific systems, but will generally contain at least those
shown below. The Configuration switch definitions may also vary for specific systems. If there are
differences from those shown, refer to the applicable reference manuals for each specific system.
DIAGNOSTICS CHECK:
To access the diagnostics feature of the VST Fuel S-810, the configuration switches
located on the Motherboard must be set as follows (See Figure 15):
Switch # 8 set to ON
After making the necessary switch changes, press the RESET button on the Motherboard, close and lock the front
panel of the VST Fuel S-810 (See Figure 15). The display on the front panel should be as follows:
ENTER DIAG #
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