Toshiba LF620 Instruction Manual page 140

● Converter diagnosis error
The converter checks the internal system when power is turned on and generates an error if
abnormality is found.
If multiple errors are found, their messages will be displayed cyclically.
Diagnosis items concerning the excitation circuit are detected using the internal ADC circuit.
Thus, if the ADC error of No.6 occurs, No. 4 excitation cable and No. 5 excitation circuit
errors cannot be detected correctly. Further, this entire diagnosis and display system is based
on the CPU in the flowmeter. Therefore, if the CPU error occurs, normal diagnosis and error
display cannot be obtained.
NO.
ROM ERROR
1
RAM ERROR
2
PARAMETER
3
FAILURE
EXC CUR
4
OPEN
EXC CUR
5
ERROR
ADC ERROR
6
INVALID
７
TOTAL
Note 1: No.1 to No.3 diagnosis items are executed only at the time of power-up. The flowmeter does
not start measurement if any one of these errors is detected.
Note 2: No.4 to No.6 diagnosis items may not be detected even if the error results in incorrect
flowmeter accuracy, due to characteristic differences in components used to detect these
errors.
Note 3: CPU error cannot be detected by the diagnosis system. If the CPU stops, the watchdog timer
resets the internal circuits and the flowmeter starts again from the initial power-un condition.
Depending on the CPU condition, the flowmeter may not indicate and output correct data.
LCD display
ROM error
RAM error
System parameter error in the memory
Excitation cables are not connected.
An error occurred in the excitation circuit.
ADC error
Totalizer data in the memory was destroyed
due to external noise.
(No message appears if data display with
volume unit is not used.)
− 139 −
Description
6 F 8 A 0 9 2 7
Corrective action
Internal components
printed-circuit board must be
repaired or replaced.
Contact Toshiba's salesperson in
charge or distributor in your area.
Connect the excitation cables
correctly.
Internal components
printed-circuit board must be
repaired or replaced.
Contact Toshiba's salesperson in
charge or distributor in your area.
The error message disappears if
you clear the totalizer count.
or
or