Description Of The Blocks; Level Transducer Block Function Groups - Siemens Sitrans Probe LU Instruction Manual

Oxley Creek WWTP Water Reclamation
(Probe LU Manual) Vendor Manual
Analog Input Function Blocks AIFB1 and AIFB2
The two Analog Input Function Blocks are completely independent of each other. They
use the output from the Level Transducer Block, and apply any required quality checks,
scaling, and Failsafe operation selections.
The output of an Analog Input Function Block supplies the measured value and
associated status information to PROFIBUS PA, via cyclic data transfer.

Description of the blocks

Level 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/ Level or Volume;
Secondary Value 1/Level; Secondary Value 2 /Distance 1; or Secondary Value 3/
Distance 2). The LTB implements all of the basic parameters (see parameter diagram
on page 57), including level to volume calculation, if that option has been selected.
Sensor
Sensor
technology
Sensor
Offset
Page 56 SITRANS Probe LU (PROFIBUS PA) – INSTRUCTION MANUAL
Sensor Value
Level
calibration
High
Calibration
Point
High Level
Point
Sensor
Level unit
conversion
Level Primary Value
[Level/Volume]
(level/volume units)
Linearization
Level
Offset Linearization
Type
Low Secondary Value 1
Calibration
[Level]
Point
(Level Units)
Low Level
Point
Secondary Value 2
[Distance 1]
(Sensor Units)
Secondary Value 2
[Distance 2]
(Level Units)
Doc Id: VM11
Active Date: 15/12/2006
PV
AIFB1
(Analog
SV1
Input)
AIFB2
(Analog
SV2
Input)
SV3
7ML19985JB02