EsiWelma TW1-M, Руководство пользователя

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Type / N°
Rev. Fw Date Page Total pages
EW055.600D D 4L 6
th
June 2018
6 43
EsiWelma ® s.r.l.
2. FUNCTIONAL DESCRIPTION
2.1. Data display
TW1 computing head can be combined with one-nozzle fuel dispensers, data are always
visualised on a 6-digit display for the amount to be paid, a 5-digit display for delivered fuel
and a 4-digit display for unit price.
TOTAL AMOUNT
DELIVERED FUEL
UNIT PRICE
Figure 2: Max data display
25mm high back lighted LCDs made up the display bars. The backlighting system is made up
of a printed circuit with a led matrix welded on. It is settled on the backside of the metal box
and gives out a green light. As an alternative it i
s possible to use the dispenser’s own light.
2.2. Operating sequence description
Once initialised, the computing head carries out some checks:
EPROM - it checks the EPROM CRC and compares it to the data reported
on the program.
RAM - it checks the writing and reading ability of data RAM.
EEROM - it checks the congruence of the data reported in EEROM.
DISPLAY - it checks the connection status of the display.
RX-TX - presence of active connection with Host.
DATA COMPLIANCE - compliance of the data used by RAM with the originals in
E
2
ROM.
UNIT PRICE - it checks that the unit price is not zeroed.
ANALOG INPUTS - it checks the presence of pressure and temperature transmitters.
MEASUREMENT - it checks that the mass flow meter (in case of MODBUS system)
is present and communicating.
MAX. PRESSURE - it checks that pressure does not exceed the maximum
functioning pressure of the plant.
If the above mentioned checks give a positive result, display temporarily shows the program
code and the data about the last delivery, then it switches-off. In case of anomalies display
shows the relevant error code (See further, “Anomalies management” §3).
When the dispenser is in stop-mode , the computing head performs continuously the
same controls described above.
p.u.
Kg