5. How to Operate
5-5. Description of operation (detection mode)
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NOTE
See "8. Troubleshooting" for remedial actions to fault display.
5-5-2
．
External output operation
4
–
20 mA transmission
(1) Signal transmission method: Electric current transmission (non-isolated)
(2) Transmission path: CVVS 2c 1.25 sq
(3) Transmission distance: 500 m or less
(4) Connection load resistance: 300
Ω
or less
(5) Status signal level
1. Detection mode: 4.0 - 20.0 mA (depends on the gas concentration)
2. Initial clear: 17.4 mA
3. Maintenance mode: 17.4 mA
4. External output test: 4.0 - 20.0 mA (varies with the test value)
5. Fault state: 21.0 mA or more
6. Power off: 0.0 mA
The following figure shows the relation between "gas concentration" and "external output".
CAUTION
The 4 - 20 mA output is adjusted. Do not attempt to perform readjustment after installation. It must be
done by a qualified service engineer.
Fault Display
If a fault occurs on the detector, the fault detail is
displayed on the LCD.
(LCD display) (Fault detail)
E-9 System abnormalities
E-1 Sensor not connected/Sensor disconnection
E-9
17.4mA
4mA
20mA
22mA
Full scale
Gas
concent
External output
0
20.9 ±0.5 vol%
(suppression value)
