Siemens HydroRanger 200 HMI, Руководство по эксплуатации

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Diagnosing and troubleshooting
10.9 Set the device to ignore the bad echo
HydroRanger 200 HMI
Operating Instructions, 06/2018, A5E36281317-AC
291
10.9 Set the device to ignore the bad echo
If the preceding remedies have not fixed the problem, the false echo has to be ignored.
If the echo is close to the transducer
If there is a static, incorrect, high level reading from the device there is probably something
reflecting a strong echo back to the transducer. If the material level never reaches that point,
extend the Blanking (2.2.6.) (Page 171) to a distance to just past the obstruction.
Adjust the TVT to ignore the bad echoes
Use Auto False Echo Suppression (2.11.3.2.) (Page 227). If this does not correct the
problem, use TVT Shaper (2.11.4.) (Page 231) to manually shape around false echoes.
10.10 Wrong reading
If the reading is erratic, or jumps to some incorrect value periodically, ensure the following
conditions:
1.
Surface monitored is not beyond the device's programmed range or the transducer’s
maximum range.
2. Material is not falling into the transducer’s acoustic beam.
3. Material is not inside the blanking distance [Blanking (2.2.6.) (Page 171)] of the
transducer.
Types of wrong readings
If a periodic wrong reading always produces the same value, see Fixed reading (Page 290).
If the wrong reading is random, ensure the distance from the transducer to the material
surface is less than Range Extension (2.2.7.) (Page 172) value plus one meter (i.e. ensure
you are still within the measurement range programmed in the device). If the material/object
monitored is outside this range, increase Range Extension (2.2.7.) (Page 172) as required.
This error is most common in OCM applications using weirs.
Liquid splashing
If the material monitored is a liquid, check for splashing in the vessel. Enter a lower response
rate value to stabilize the reading, or install a stilling well. Contact your Siemens
representative for assistance.
Adjust the echo algorithm
Use SIMATIC PDM to view echo profiles and make adjustments to the Algorithm parameter.
See Algorithm (2.11.2.2.) (Page 222).
If narrow noise spikes are evident on the echo profile, widen the Narrow Echo Filter
(2.11.2.6.) (Page 224). Also, if the true echo has jagged peaks, use Reform Echo (2.11.2.5.)
(Page 223).