42
STARTUP
At startup the firmware release code scrolls through the LCD;
it is possible to escape from code scrolling pressing any key.
During the automatic startup the Real Time Clock (RTC) is
checked to see if a reset occurred since last software initial-
ization. In this case, the RTC is initialized with the default
date and time 01/01/1997 - 00:00. An EEPROM reset does
not affect the RTC settings.
The EEPROM is also checked to see if it is new. If this is the
case, the default values are copied from ROM and then
the device enters normal mode. Otherwise an EEPROM
checksum test is performed (the same is performed during
EEPROM selftest procedure).
If checksum is correct, normal mode is entered, otherwise
user is asked whether the EEPROM should be reset.
If EEPROM reset is requested, default values from ROM are
stored into EEPROM as would happen with a new EEPROM.
Note that EEPROM data is composed of setup data and
calibration data. As for the setup data, the calibration data
is assigned default values when an EEPROM reset occurs.
An un-calibrated meter can perform
measurement, though user is informed
that pH calibration (pH models) or mV
calibration (mV models) is needed by
means a blinking “CAL” icon.
When the last calibration data is
required, the “no CAL” message is
displayed if no calibration procedure
was performed.
Unlike pH and mV calibration, user has no information
on calibration need for other magnitudes, other than the
awareness that EEPROM was reset.
After an EEPROM reset, all calibrations (input and output)
have to be performed in order to obtain correct measure-
ments.
