ELECTRONIC PERSONAL DOSEMETER HANDBOOK
EPD/HB/40521/000
FAULTS AND RECOVERY ACTIONS
ISSUE 5
Thermo
Page
69
5.5
Initialisation Error ( LCD - - - - )
A series of single dashes appearing on the LCD display indicates an initialisation
error following a reset or battery change:
Initialisation errors typically refer to corruptions to data in the EPD’s non volatile
memory (EEPROM). These are faults the user cannot usually repair. Follow the
procedures defined in section 8 to extract data and to recover normal operation
where possible.
5.6
Communications Error ( LCD
≡≡≡≡
)
A series of triple dashes appearing on the LCD display indicates a
communications error:
This condition usually occurs when a data write operation fails to complete. The
typical cause is that the EPD unit is removed from the IR field before a critical
write operation has completed, for example an Issue of the EPD to a person.
The error ( which is accompanied by an audible alarm ) alerts the user that the
EPD is not in a valid operational state. However as described above, the cause is
a user / operational problem and not a fault in the EPD.
An EPD will only raise this condition if it is first triggered by the system software,
in effect a message is passed to the EPD saying: “raise an alarm if the following
write operations don’t complete successfully within ‘N’ seconds.” If the condition
does occur then it is necessary to train the users not to remove the EPD from the
