Yokogawa YVP20S - Manual (Page 171)

App-2
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IM 21B04C50-01E
TA01-2.EPS
Connector A Connector is a coupling device used to connect the wire medium to a fieldbus device or to another
segment of wire.
Control Loop A Control Loop is a group of Function Blocks (FBs) that execute at a specified rate within a fieldbus
device or distributed across the fieldbus network.
Coupler A Coupler is a physical interface between a Trunk and Spur, or a Trunk and a device.
decimal Notation for numbers to base 10. The number sequence is 0,1…9.
D Derivative time or rate time is the time constant of derivative control expressed in seconds. A value
of zero disables derivative action.
Fieldbus Access
Sublayer (FAS) The Fieldbus Access Sublayer (FAS) maps the Fieldbus Message Specification (FMS) onto the Data
Link Layer (DLL).
Fieldbus Messaging
Specification (FMS) The Fieldbus Messaging Specification (FMS) contains definitions of Application Layer services in
FOUNDATION fieldbus. The FMS specifies services and message formats for accessing Function
Block (FB) parameters, as well as Object Dictionary (OD) descriptions for those parameters defined
in the Virtual Field Device (VFD).
Hot swappable The YVP in combination with ValveNavi enables a very brief Mean Time To Repair by the following
process: Upload all configuration information from installed positioner to ValveNavi, then replace the
positioner and download the configuration file. Run STOPS, and autoTUNE, and the repair is
complete.
Flexible Function
Block A Flexible Function Block (FB) is similar to a Standard FB, except that the function of the block, the
order and definition of the block parameters, and the time required to execute the block are
determined by an application-specific algorithm created by a programming tool. Flexible Function
Blocks (FBs) are typically used for control of discrete processes and for hybrid (batch) processes. A
Programmable Logic Controller (PLC) can be modelled as a Flexible Function Block device.
Flash Memory A computer memory which is not volatile. It stores all its data even when the power is off. It
performs high speed reads and may be re-written many times. It is used to store programs and
permanent parameters.
hexadecimal Notation for numbers to base 16. The number sequence is 0,1…9, a, b, c, d, e, f to represent
decimal 0 to 16. Customarily hexadecimal notation is identified with the preamble 0x.
High Speed Ethernet
(HSE) High Speed Ethernet (HSE) is the Fieldbus Foundation’s backbone network running at 100
Mbit/second.
H1 Repeater An H1 Repeater is an active, bus-powered or non-bus-powered device used to extend the range
over which signals can be correctly transmitted and received for a given medium. A maximum of four
Repeaters and/or active Couplers can be used between any two devices on an H1 fieldbus network.
Device Description
(DD) A Device Description (DD) provides an extended description of each object in the Virtual Field
Device (VFD), and includes information needed for a control system or host to understand the
meaning of data in the VFD.
Damping Coefficient The valve response may be made slower for some applications. A value of 0 gives no damping, and
a value of 9 gives maximum damping of valve motion.
H1 H1 is a term used to describe a fieldbus network operating at 31.25 kbit/second.
Hazardous Area The area of the plant where explosion hazards may be present, hazards such as propane gas in a
refinery, or dust in a flour mill.
DI Digital Input Block
Data Link Layer (DLL) The Data Link Layer (DLL) controls transmission of messages onto the fieldbus, and manages
access to the fieldbus through the Link Active Scheduler (LAS). The DLL used by FOUNDATION
fieldbus is defined in IEC 61158 and ISA S50. It includes Publisher/Subscriber, Client/Server and
Source/Sink services.
Dead Zone(%) When the valve position is within the setpoint +/- the dead zone, no additional position control is
performed. This value is normally 0%, however for high friction valves (e.g. valves with graphite
packing) a higher dead zone will help avoid limit cycling due to the stick/slip action of the valve. In
these cases the dead zone chosen might be 0.2% to 1%.
Fieldbus A Fieldbus is a digital, two-way, multi-drop communication link among intelligent measurement and
control devices. It serves as a Local Area Network (LAN) for advanced process control, remote
input/output and high speed factory automation applications.
H1 Field Device An H1 Field Device is a fieldbus device connected directly to an H1 fieldbus. Typical H1 Field
Devices are valves and transmitters.
Condition Monitoring A technology for measuring the performance of process equipment and valves over a period of time
to predict the need for maintenance. The technology evolved to meet NRC requirements GL 89-10,
and has proven valuable to other process industries. ValveNavi offer a suite of diagnostic tools to
implement condition monitoring.