Yokogawa AXFA14G/C - Manual (Page 7)

IM 01E20F12-01E 2-1
2. ABOUT PROFIBUS PA
2. ABOUT PROFIBUS PA
2.1 Outline
PROFIBUS PA is a widely used bi-directional digital
communication protocol that enables the implementation
of technologically advanced process control systems. The
AXF Series PROFIBUS PA communication type meets
the specifications of PROFIBUS Nutzerorganisation e.V.
and is interoperable with devices from Yokogawa and
other manufacturers.
For information on other features, engineering, design,
construction work, startup and maintenance of
PROFIBUS PA, please download the adequate documents
and read them by visiting the following web-site of
PROFIBUS Nutzerorganisation e.V..
http://www.profibus.com/
2.2 Internal Structure of AXF
The AXF contains four blocks that share the following
functions:
(1) Physical block
• Manages the status of AXF hardware.
• Automatically informs the host of any detected
faults or other problems.
(2) Transducer block
• Converts sensor output to flow rate signal and
transfers to AI function block.
(3) AI function block
• Conditions raw data from the transducer block.
• Outputs flow rate signal.
• Carries out scaling and damping extraction.
(4) Totalizer function block
• Totalization of raw data from the Tranceducer
block.
(5) Dl function block
• Conditions discrete data from the Tranceducer
block.
2.3 Logical Structure of Each
Block
AXF
F0201.EPS
Physical block
Block tag
Parameters
AI block
TOT block 1
TOT block 2
TOT block 3
DI block 1
Sensor
input
Output
SENSOR
Transducer block
Block tag
Parameters
DI block 2
Block tag
OUT_D
Parameters
Sensor
Figure 2.1 Logical Structure of Each Block
The parameters shown in Figure 2.1 must be set before
starting operation.
2.4 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 allow device performance to be fully exhibited.