Overview Of Measurement Types - Siemens SITRANS P300 Operating Instructions Manual

The following device variables are available:
• Pressure
• Sensor temperature
• Electronics temperature
• Pressure (untrimmed)
These device variables are always active and are therefore always displayed.
All other device variables only contain a valid measurement value if the associated
measurement type has been activated and also configured.
The inactive device variables have the status CONSTANT.
7.4.2

Overview of measurement types

Overview
With a few parameters, the transmitter can be set to the relevant measuring task. When
doing so, you are aided by the following selectable measurement types and a user
programmable characteristic curve:
• Pressure
• Level
One or more device variables are permanently allocated to each measurement type. These
device variables are displayed in SIMATIC PDM or in the HART Communicator and are
activated using the buttons in the following order:
• Pressure
• Sensor temperature
• Electronics temperature
• Pressure (untrimmed)
When operating via HART communication, you will find the following as well:
• Measurement type selector
The device variables are always active and are therefore always displayed. All other device
variables only contain a valid measurement value if the associated block has been activated
and also configured. The inactive device variables have the status CONSTANT.
In addition to the "Pressure" block, you can use the measurement type selector to activate
one of the other three blocks, "Sensor temperature", "Electronics temperature", or "Pressure
(untrimmed)". In that case, it needs to be configured with the applicable parameters. This
does not mean that this block automatically influences the output of current (4 to 20 mA). For
that, you need to switch the corresponding device variable to "Primary Variable" (PV) using a
"mapper".
Measurement type "Pressure" => Device variable "Pressure", "Sensor temperature",
"Electronics temperature", "Pressure (untrimmed)"
SITRANS P300 with HART communication
Operating Instructions, 06/2005, A5E00359579-02
You can use this selector to switch between the measurement types "Pressure", "Level",
and a characteristic curve that can be programmed by the user.
Operating functions via HART
7.4 Selecting the measurement type
7-3