Honeywell SLG 700 Option Manual page 158

Full Tank Detection:
Full tank detection enables the detection of a level within the upper blocking distance at startup and it
ensures reliable measurement when the block distance high (BDH) is reduced below the transition
upper distance.
This feature enables the transmitter to perform additional analysis on the data in the region near the
reference plane where the product reflections become mixed with reflections from the physical
mounting components such as a flange or nozzle. This additional analysis allows the transmitter to
detect the presence of product in this region even if the shape of the product reflections deviate
significantly from the expected shape. This option should only be enabled if a recently captured Field
or Obstacle background is in use (see below) and the Dielectric Constant of the Upper Product is above
12. It should not be enabled for products with low Dielectric Constants or when the Factory
background type is being used.
In a demanding application where measurements close to the process connector are required but large
temperature fluctuations are expected it is also recommended to enable Dynamic Background updates
as discussed below.
Dynamic Background update:
The feature provides enhanced immunity against measurement conditions by dynamically adjusting the
active Field or Obstacle background profile. (This feature is not available for the Factory Background
Type.) With Dynamic Background enabled, the sensor periodically schedules automatic updates to the
background echo profile. Echoes are only updated if the level is outside of the transition zones (see
section Transition zones) and the signal is of good quality. Data is collected up to approximately 30 cm
from the level at the time, if this distance is within the requested background echo length.
The most recently updated background is also stored in permanent memory and is applied after a
sensor reset if dynamic background is enabled. At all times the sensor maintains a copy of the original
user acquired (static) background echo and will revert to this if the dynamic background feature is
once again disabled. Re-enabling dynamic background at that point starts the process anew. It is
recommended that this feature is turned on in all installations where probe build-up or large ambient
temperature swings over 30°C are expected.

Background Capture: This group of controls provide the mechanism for obtaining new
background echoes for the Field and Obstacle background types described above. These
controls are only visible when no other parameters are being edited as the background echoes
are inherently dependent on the current mounting configuration. All edits must be applied or
discarded before a background capture may be started.

Background Length Type: This control allows the user to select the type of background
profile that should be collected as either Field or Obstacle. (The Factory background profile
is completely static and cannot be captured or dynamically updated.) This type parameter does
not have to be the same as the active Background Type parameter described above which is
located outside this group of controls. In fact, a Field or Obstacle background profile must be
collected first before it can be activated.

Background Length: This control allows the user to enter the desired length of background
profile to collect as measured from the Reference Plane. For the Field background type the
control will be automatically populated with a preset length based on the current mounting
configuration. The length cannot be increased beyond this preset value and should only be
lowered in extreme cases when it is not possible to bring the surface of the product below this
length. For the Obstacle background type the control will also be automatically populated with
this preset length but the value may be increased as required to cover all obstacles, up to the
measureable length of the probe.
Page 142 FOUNDATION Fieldbus Option User's Guide Rev. 3.0