Hanna Instruments HI 504, Инструкция по эксплуатации

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92
FAULT CONDITIONS
The below fault conditions may be detected by the software:
• EEPROM data error
• serial communication internal bus failure
• software dead loop .
EEPROM data error can be detected through EEPROM
test procedure at start-up or when explicitly requested us-
ing setup menu, or during normal operational mode if a
checksum control fails .
When an EEPROM error is detected during normal mode,
a fault alarm is generated according to the user configura-
tion for the EEPROM corruption error (see “Alarm” section) .
To close an error an EEPROM test (see “Selftest procedures”
section) or reset is required .
As soon as an EEPROM error is detected, the scrolling
message “EEPROM reset needed - Press up button to reset
stored data or right button to ignore” will appear on the
primary LCD .
If the

key is pressed, the process controller restarts opera-
tion, but alarm actions are performed as configured by the
user (see “Alarm - Error configuration” section) . Note that
the device will be in Hold mode in any case .
If the

key is pressed, all the data stored in the EEPROM
are erased and the default values loaded . After that, the
device must be completely recalibrated .
An internal bus error is detected when internal transmission
is not acknowledged or a bus fault occurs for more than a
certain number of unsuccessful transmission attempts (due
for example to a damage occurred to one of the ICs con-
nected to the internal bus) . After that the controller displays
a sliding message “Serial bus error” .