Siemens SITRANS P DS III - Page 96

Operator control functions via PROFIBUS
7.1 Communications structure for PROFIBUS PA
SITRANS P DS III with PROFIBUS PA
96 Operating Instructions, 06/2013, A5E00053276-07
Pressure transducer block
The transducer block for pressure handles the adaptation to the pressure sensor. Its output
value is the linearized and temperature-compensated measurement result. When measuring
levels and flow, the necessary recalculation of the measurement value is performed in the
pressure transducer block. The output value is the linearized and temperature-compensated
measurement result.
The pressure transducer block also processes the temperature measurement of the
pressure sensor and monitors the pressure and temperature limits.
Example
In hydrostatic level measurement, the pressure transducer block converts the incoming
pressure value into height or volume.
Electronics temperature transducer block
The electronics temperature transducer block executes the required temperature
measurement functions and monitors the permissible temperature limits.
Analog input function block
The analog input function block further processes the selected measurement value and
passes it on to the automation task.
Example
For a container full of water, you measure the volume. The analog input function block
calculates the container volume [m
3
] in a user-specific volume unit [bottles]. The output of
this block gives the measured value and the corresponding status on the PROFIBUS.
Totalizer function block
The totalizer function block totals the volumes or mass that flowed during flow measurement.
Its function is very similar to that of a water meter.
The output of this block forwards the totalized values and the corresponding status
information via PROFIBUS.
Local operation and display
The display shows the desired measured value with its physical unit. You can select different
functions for local operation.