Echo Lock; Loss Of Echo (Loe); Loe Timer - Siemens SITRANS LR200 Instruction Manual

Echo Lock

When the echoes are received, the relevant echo algorithm is applied to determine the
true material echo. If the selected echo is within the window, the window is then
centered about the echo. Otherwise the window widens with each successive shot until
the selected echo is within the window, which then returns to its normal width.
Echo Lock selects the measurement verification process:
Values
• When Echo Lock is Off, SITRANS LR 200 responds immediately to a new
measurement (within the restrictions set by the Maximum Fill / Empty Rate).
However, measurement reliability is affected.
• When Maximum Verification or Material Agitator is selected, a new measurement
outside the Echo Lock Window must meet the sampling criteria.
• When Total Lock is selected, Echo Lock Window is pre-set to 0, and the window is
automatically calculated after each measurement.

Loss of Echo (LOE)

A loss of echo (LOE) occurs when the calculated measurement is judged to be unreliable
because the echo confidence value has dropped below the echo confidence threshold.
The LOE timer starts running, and if the LOE condition persists beyond the time limit set by
the LOE timer, the Reliable Echo indicator is replaced by the Unreliable Echo indicator.
Reliable Echo indicator
Unreliable Echo indicator: border flashes when LOE is pending.
When LOE is active border is solid and text region displays S: 0
Upon receiving a reliable echo, the loss of echo condition is aborted, the Reliable Echo
indicator replaces the Unreliable Echo indicator, and the reading returns to the current
level.

LOE Timer

The LOE timer determines the time (in minutes) to elapse after the last valid reading
before Failsafe mode is activated. When the LOE timer expires, the material level to be
reported is determined by Failsafe Mode.
Page 34 SITRANS LR 200 (PROFIBUS PA)– INSTRUCTION MANUAL
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Off
1
Maximum Verification
2 *
Material Agitator
3
Total Lock
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