Siemens SITRANS LR250 Operating Instructions Manual page 100

Remote operation
7.1 Operating via AMS Device Manager
Echo Select
[see Echo Select (2.5.7.)]
● Algorithm [see Algorithm (2.5.7.1.)]
● Position Detect [see Position Detect (2.5.7.2.)]
● Echo Threshold [see Echo Threshold (2.5.7.3.)]
● CLEF Range [see CLEF (Contrained Leading Edge Fit) Range (2.5.7.4.)]
Sampling
[see Sampling (2.5.8.)]
● Echo Lock [see Echo Lock (2.5.8.1.)]
● Sampling Up [see Up Sampling (2.5.8.2.)]
● Sampling Down [see Down Sampling (2.5.8.3.)]
Echo Quality
[see Echo Quality (2.5.9.)]
● Confidence [see Confidence (2.5.9.1.)]
● Echo Strength [see Echo Strength (2.5.9.2.)]
● Noise Average
Displays the average ambient noise (in dB above 1 μV rms) of a noise profile. Noise level is a
combination of transient noise and receiving circuitry. After a measurement, the values from
the previous noise shot will be displayed.
TVT (time varying threshold)
A time-varying curve that determines the threshold level above which echoes are determined to
be valid.
Modify the TVT to screen out false echoes [see Time Varying Threshold (TVT) (Page 266), and
Auto False Echo Suppression (2.5.10.1.)].
Navigate to Configure/Setup > LTB > Setup > Signal Processing and click on TVT. Click on one
of the two tabs to access the parameters listed:
TVT Setup
● Auto False Echo Suppression [see Auto False Echo Suppression (2.5.10.1.)]
● Auto False Echo Suppression Range [see Auto False Echo Suppression Range (2.5.10.2.)]
● Hover Level [see Hover Level (2.5.10.3.)]
● Shaper Mode [see Shaper Mode (2.5.10.4.)]
100
SITRANS LR250 (FOUNDATION FIELDBUS)
Operating Instructions, 08/2014, A5E32221411-AC