Description Of The Blocks - Siemens Sitrans LR250 Operating Instructions Manual

Description of the blocks

Transducer Block function groups
The figure below shows the signal flow of measured values from the sensor through the
Transducer Block into the output value:
• Primary Value (PV): Level or Volume
• Secondary Value 1 (SV1): Level
• Secondary Value 2 (SV2): Distance
The Transducer Block implements all of the basic parameters (see parameter diagram on
page 141), including level to volume calculation, if that option has been selected.
Transducer Block
Sensor Value
Sensor
Sensor
technology
Sensor
Offset
Transducer Block
How the
1) The sensor technology block selects the proper echo. For an explanation of sensor
technology, see
The sensor value (in sensor units) is checked to see if it is within its measuring limits.
If the limit is exceeded, this results in a Bad status and the error message Failure in
measurement. The sensor value is stored in Sensor Value.
The analog signal from the sensor is transformed into a digital representation.
A Sensor Offset (default 0) compensates for changes to the sensor reference point,
if necessary.
Page 140 SITRANS LR250 (PROFIBUS PA) – OPERATING INSTRUCTIONS
Level
Level
calibration
Level
Offset
Low
High
Calibration
Calibration
Point
Point
Low Level
High Level
Point
Point
Calibration
Type
works:
Appendix D: Technical Reference
Primary Value
[Level/Volume]
(level/volume units)
PV
Linearization
Linearization
Type
SV1
Secondary Value 1
[Level]
(Level Units)
SV2
Secondary Value 2
[Distance]
(Sensor Units)
, page 122 onwards.
AIFB1
(Analog
Input)
AIFB2
(Analog
Input)
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