Yokogawa FVX110 - Manual (Page 26)

<4. About Fieldbus>
4-1
IM 01S01C01-01EN
4. About Fieldbus
4.1 Outline
Fieldbus is a widely used bi-directional digital
communication protocol for field devices that
enable the simultaneous output to many types of
data to the process control system.
FVX110 Fieldbus Segment Indicatior employs
the specification standardized by The Fieldbus
Foundation, and provides interoperability between
Yokogawa devices and those produced by other
manufacturers.
For information on other features, engineering,
design, construction work, startup and maintenance
of Fieldbus, refer to “Fieldbus Technical Information”
(TI 38K03A01-01E).
4.2 Internal Structure of FVX110
The FVX110 contains two virtual field devices
(VFD) that share the following functions.
4.2.1 System/network Management VFD
• Sets node addresses and Physical Device tags
(PD Tag) necessary for communication.
• Controls the execution of function blocks.
• Manages operation parameters and
communication resources (Virtual
Communication Relationship: VCR).
4.2.2 Function Block VFD
(1) Resource block
• Manages the status of FVX110 hardware.
• Automatically informs the host of any detected
faults or other problems.
(2) LCD Transducer block
• Controls the display of the integral indicator.
(3) MAO function block
• Transfers 8 analog variables of the IO
subsystem to transducer block using 8 input
parameters (IN_1 to IN_8).
(4) PID function block
• Performs the PID control computation based on
the deviation of the measured value from the
setpoint.
(5) SC function block
• Uses the line-segment function to convert input
signal values.
(6) IT function block
• Integrates input signal values.
(7) IS function block
• Same as MAO function block, this block
transfer 8 analog variables (IN_1 to IN_8) to
transducer block.
• Provides a function for automatic selection of
one signal from multiple input signals using a
specified method of selection.
(8) AR function block
• Applies gain multiplication and bias addition
to the calculated result through use of multiple
computing equations to perform limitation
processing for output.