YOKOGAWA RC400G, Руководство пользователя

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<6. Converter Operating Functions>
6-3
IM 12F4A1-01E
F6.2.ai
Detecting
voltage
Setting
voltage
0
Time
Applied coltage
A few sec.
Reverse voltage
Figure 6.2 Detecting Voltage Waveform
6.1.4 Converter Failure (Err14, Err15, Err16, and Err17)
Converter circuit failure and memory failure are detected in the following method:
(1) AD Circuit Failure (Err14)
By periodically sampling the reference resistance value and reference voltage value in the
temperature input circuit, check whether these values are the predetermined ranges or not.
If a value exceeds the predetermined range, error code “Err14” <failure> is displayed.
(2) Memory Comparison Failure (Err15)
Each data such as setpoint is stored in two areas in the memory (EEPROM).
During converter operation, each data stored in two areas is periodically mutually
compared. If data which does coincide is detected, error code “Err15” <failure> is displayed.
When memory failure is detected, memory contents are initialized in very rare case. In this
case, the setting data may be lost.
(3) Memory R/W (Read/Write) Failure (Err16, Err17)
Immediately after converter power is turned ON, the memories that are used (RAM and
EEPROM) are checked.
For RAM, by performing the specified data “writing” and “reading”, check if both coincide.
When they do not agree, error code “Err16” <failure> is displayed.
For EEPROM, check that the data items stored in two areas coincide. If both do not agree,
by performing the specified data “writing” and “reading”, check if both coincide. When they
do not agree, error code “Err17” <failure> is displayed.
When these failures are detected, the converter displays error code “Err16” or “Err17” and
stops operation (key operation cannot by conducted).
When memory failure is detected, memory contents are initialized in very rare case. In this
case, the setting data may be lost.
6.1.5 Concentration Upper Limit Setpoint Exceeded (Err25)
Residual chlorine concentration measured value that exceeds the value set using function code
“b” in <PROGRAM.1> mode is handled as failure.
When it is detected that the measured concentration exceeds the setpoint in <MEAS.> mode,
error code “Err25” <failure> occurs and a contact signal is output.
This contact output can also be used as an “upper limit alarm”. However, since this contact output
is shared by other <failure> contact outputs, fully exercise care for its use as the “upper limit
alarm”.
This failure detecting function “execution/stop” can be selected using function code “5.” in
<PROGRAM.2” mode.
14th Edition : Jul. 15, 2020