Analog Input Function Block - Siemens SITRANS P DS III Operating Instructions Manual

Operator control functions via PROFIBUS
7.1 Communications structure for PROFIBUS PA
7.1.5

Analog input function block

The analog input function block is part of the standard functions of pressure transmitters.
The following figure shows the processing of the measured values up to the output.
Image 7-5 Function groups of the analog input function block
M
i
OUT Output (value, status)
Operating principle
The incoming measurement value from the pressure transducer block - or a simulated value
prescribed through the simulation switch - is subject to another normalization (measured
value scaling) and a projection onto the output range through output scaling (application-
specific measured value).
Afterwards, the signal is filtered (damping) and check for being within preset limit values. An
upper and lower warning and alarm limit is always available.
If the measured value has the status "Bad", the shutdown logic can output a safety preset
value: This may be the last usable measured value or a preset substitute value.
104
Incoming measured value from the trans-
ducer for pressure
MAN Manual
O/S Out of Service
AUTO Automatically
SITRANS P DS III/P410 with PROFIBUS PA
Operating Instructions, 02/2016, A5E00053276-08