Siemens sitrans LU10 - Page 35

7ML19985AN02 SITRANS LU10 – INSTRUCTION MANUAL Page 31
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Application Parameters
P070 FAILSAFE TIMER
Enter the time to elapse (in minutes), upon a difficulty, before failsafe operation
is activated.
In the RUN mode, when a difficulty first occurs, the Reading, Bar Graph, relay
status, and mA outputs are held at "last known" values and the Failsafe Timer is
activated.
When a valid measurement is made before the timer expires, the SITRANS LU10
advances to the "new" material level (if changed) as normal (per Measurement
Response, P003) and the timer resets.
If the timer expires (before a valid measurement is made), the SITRANS LU10
advances to the Failsafe Material Level (P071) as restricted by Failsafe Advance
(P072).
When a valid measurement is made after the timer expires, the SITRANS LU10
advances to the "new" material level (if changed), as restricted by Failsafe
Advance (P072) and the timer resets.
If the timer expires due to a measurement difficulty, "LOE" flashes in the Reading
display.
Technical difficulty messages flash in the Reading display before the timer
expires. The offending terminal connections are displayed in the Auxiliary
Reading display
DISPLAY CAUSE
"LOE" weak echo (see
Troubleshooting Guide Measurement
Difficulties)
"Short" short circuited transducer cable, or defective transducer
"OPEn" open circuited transducer cable, or Point Number is scanned but
a transducer is not connected, or defective transducer
"Error" reversed Ultrasonic/Temperature transducer terminal
connections or wrong Transducer (P004) entered.
While a short duration Failsafe Timer value may be required
While a short duration Failsafe Timer value may be required While a short duration Failsafe Timer value may be required
While a short duration Failsafe Timer value may be required
(when process control equipment is used) avoid entering
(when process control equipment is used) avoid entering (when process control equipment is used) avoid entering
(when process control equipment is used) avoid entering
a value so short as to cause nuisance activation.
a value so short as to cause nuisance activation.a value so short as to cause nuisance activation.
a value so short as to cause nuisance activation.
This feature is automatically altered when Measurement Response (P003) is
altered.
values: 0.000 to 9999