Toshiba LF434 - Manual (Page 136)

TOSHIBA
6 F 8 A 0 7 7 0
Converter hardware failure
The system checks ihc internal drcuilry at the time of power-up for all error items and
checks eonliiiuously for the specified hems ys described belown If an error is detected, one
of the messages shown in the table below will be displayed,
If multiple errors occur, their messages will be displayed cyclically. The diagnostics items
concerning the excitation cable and excitation circuit are detected using the ADC circuit.
Thus, if the ADC fails. No. 4 (excitation cable) and No. ^ (excitation circuit) errors can
not be detected correctly. Further, this entire checking system is based on the CPU in the
flowmeter. Therefore, if the CPU fails, no accurate diagnostics or error message display
can he obtained.
No. Error message Description Corrective action
1
* ROM ERROR * ROM error
Internal componcnis or
printed'CTTOuit board must be
repaired or replaced.
Contact your nearest Toshiba
representative.
2 * RAM ERROR t RAM error
3 PARAMETER FAIL System parameter error
4 EX, CURR. OPEN
Excitation cables are not
connected,
Connect the excitation cables
correetJv.
S EX, CURR, ERROR
An error occurred in the
excitation circuit. Internal components or
printed-circuit board must be
repaired or replaced.
Contact your nearest 'Jbshiba
representative.
6 ADC, ERROR ADC error
7 IliVALID TOTAL
Totalizer data was destroyed
due to external noise. (No
message appears if totalization
is not used )
I h c error mc,ssagc disappears
if you pres,s the reset key.
NOTES
1
,
Errors No, 1 to No. 3 can be detected only at the time of power-up. The flowmeter
does not start measurement if any one of these errors is detected. If these errors
occur after powcf-up, the flowmeter cannot delect Ihese errors, and thus may
indicate and ouiput incorrect daui.
2, Errors No, 4 to No. 6 may not be detected even if the errors result in incorrect
flowmeter accuracy, because of characteristic differences in components used to
delect these errors,
3. C"PU error cannot be detected. If the CPU stops, the watchdog timer resets the
internal circuits and the flowjnctcr starts again from the initial power-up condition.
Depending on CPU condition, the flowmeter may not indicate and output correct
data.
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