Siemens SITRANS P300 Operating Instructions Manual page 81

Description
Figure 7-2 Measurement type "Level"
DV Device Variable
PV Primary Variable
SV Secondary Variable
TV Tertiary Variable
QV Quarternary Variable
The first function, "Input scaling, pressure", sets the pressure range used by the following
functions in all three blocks in the same way. Ideally, this range corresponds to the sensor
limits of the transmitter that are assumed in a calculation example for all blocks with 0 and
4 bar. However, you can also set a downscaling of e.g. 1:2. This means that 50% of the
nominal measuring range, i.e. 2 bar in this example, controls fully 100% of the following
characteristic curve.
Use the "Output scaling, level" to set the measuring limits for the measurement type "Level"
with a unit from the level range. The parameter settings in the example should be 10 and
20 m. Then, at 0 bar process pressure, 10 m is displayed in DV4 and 20 m at 2 bar. The
values for the zero and limit, which are effective for the analog output, are configured in the
analog output block.
In the example, the two pairs of values 0%;0% and 100%;100% are configured for the
customized characteristic curve, which is also the default setting. This means that the
measured value from the pressure scaling is transferred 1:1 in this example.
SITRANS P300 with HART communication
Operating Instructions, 06/2005, A5E00359579-02
7.4 Selecting the measurement type
MA Zero value
ME Limit value
Operating functions via HART
7-7