About profibus pa, 1 outline, 2 internal structure of dpharp – Yokogawa EJX115A User Manual

Page 16: 1 function block, 3 logical structure of each block, 4 wiring system configuration, About profibus pa -1, Outline -1, Internal structure of dpharp -1 3.2.1, Function block -1

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<3. About PROFIBUS PA>

3-1

IM 01C25T04-01EN

3. About PROFIBUS PA

3.1 Outline

PROFIBUS PA is a widely used bi-directional

digital communication protocol that enables the

implementation of technologically advanced

process control systems. The DPharp EJX/EJA

Series PROFIBUS PA communication type meets

the specifications of PROFIBUS Nutzerorganisation

e.V. and is interoperable with devices from

Yokogawa and other manufacturers.

3.2 Internal Structure of DPharp

3.2.1 Function Block

The transmitter contains five function blocks that

share the following functions:

(1) Physical block

• Manages the status of transmitter hardware.

(2) SENSOR Transducer block

• Converts sensor output to pressure, static

pressure, and capsule temperature signals, and

transfers to the AI function blocks.

• Carries out square root signal characterize

extraction.

• Flow rate calculation.

(3) LCD Transducer block

• Controls the display of the integral indicator.

(4) AI (Analog Input) function block

• Condition raw data from the Transducer block.

• Output differential pressure, static pressure

and capsule temperature signals setting via the

channel.

• Carry out scaling, damping and square root

extraction.

(5) Totalizer function block

• Execute totalizer management of signal from AI

function block.

• Output totalized signal.

3.3 Logical Structure of Each

Block

F0301.ai

DPharp

PROFIBUS PA

Physical block

Block tag

Parameters

LCD

Transducer block

Block tag

Parameters

LCD

Totalizer function

block

AI function

block

AI function

block

Sensor

input

Output

SENSOR

Transducer block

Block tag

Parameters

AI function

block

Block tag

OUT

Parameters

Sensor

Figure 3.1

Logical Structure of Each Block

Setting of various parameters, Bus addresses, and

TAG is required before starting operation.

3.4 Wiring System Configuration

The number of devices that can be connected to

a single bus and the cable length vary depending

on system design. When constructing systems,

both the basic and overall design must be carefully

considered to achieve optimal performance.

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