Scaling Of The Digital Display Value - Siemens SITRANS P300 Operating Instructions Manual

Note
If, when setting the analog output, the values for zero point and limit point are more than
20% below or above the limit values of the set PV (set using the mapper), the values will be
rejected by the device. The values configured previously are retained. Similarly, the span
must not fall below the minimum.
Minimum span = Limit point - Zero point
The square root extraction function can only be selected in the "Pressure" measurement
type.
7.4.10

Scaling of the digital display value

Introduction
Regardless of the setting of the measurement type selector, the Primary Variable (PV) and
the display unit defined with the PV, you can scale the value shown on the digital display as
desired and allocate it any unit of 5 characters. To do so, use the Digital Display Settings
item in SIMATIC PDM or in the HART Communicator.
This scaling is based on the percentage value of the PV, which is also used for scaling the
current output. In other words, set the output scaling PV in SIMATIC PDM. After selecting
the Digital Display Settings menu command, you need to enter a start value, an end value
and a unit string.
This display selection takes priority over all other possible options. Conversion to%, mA or
another unit is not possible in this state. To do that, you need to switch the LCD scaling off
again.
Example
In the example, zero point with 0 m and limit point with 10 m are assumed in measurement
type "Level". With a process pressure of 0.4 bar, 2 m is displayed.
SITRANS P300 with HART communication
Operating Instructions, 06/2005, A5E00359579-02
Operating functions via HART
7.4 Selecting the measurement type
7-15