Appendix J: PROFIBUS PA Profile Structure

PROFIBUS Level Device Design

The device follows the profile block model and is implemented as a Profile 3.01, Class B, PA device. Standard profile parameters are used to program the Level Transducer Block.

Block Model for recording and processing measured values

The functions of the device are divided into blocks for different areas of responsibility. They can be parameterized by acyclic data transfer via PDM.

 

sensor

 

electronics

 

temperature

 

Level

sensor

Transducer

 

Block

Analog Input

 

Function Block1

 

 

PA

Analog Input

PROFIBUS

Function Block2

 

The device is implemented with one Level Transducer Block (LTB), and two Analog Input Function Blocks (AIFB1 and AIFB2).

All data is viewed from the perspective of the DCS or PLC, so information from the sensor is an input.

Level Transducer Block (LTB)

The Level Transducer Block (LTB) carries out adjustments to the sensor, such as level calibration. It supplies the outputs utilized by either or both of the AIFBs.

Analog Input Function Blocks AIFB1 and AIFB2

The two AIFBs are completely independent of each other. They utilize the output from the TB, and apply any required quality checks, scaling, and Fail-safe operation selections.

The output of an Analog Input Function Block supplies the measured value and associated status information to PROFIBUS PA, via cyclic data transfer.

J: Profile structure PA

7ML19985JM01

SITRANS LR 460 (PROFIBUS PA) – INSTRUCTION MANUAL

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Siemens LR 460 Appendix J Profibus PA Profile Structure, Profibus Level Device Design, Profile structure PA