Fisher FIELDVUE DVC6200 Instruction Manual page 106

DVC6200 Digital Valve Controller
Memory
A type of semiconductor used for storing
programs or data. FIELDVUE instruments use
three types of memory: Random Access Memory
(RAM), Read Only Memory (ROM), and
Non-Volatile Memory (NVM). See also these
listings in this glossary.
Menu
A list of programs, commands, or other activities
that you select by using the arrow keys to
highlight the item then pressing ENTER, or by
entering the numeric value of the menu item.
Minimum Closing Time
Minimum time, in seconds, for the travel to
decrease through the entire ranged travel. This
rate is applied to any travel decrease. Valid
entries are 0 to 400 seconds. Deactivate by
entering a value of 0 seconds.
Minimum Opening Time
Minimum time, in seconds, for the travel to
increase through the entire ranged travel. This
rate is applied to any travel increase. Because of
friction, actual valve travel may not respond in
exactly the same time frame. Valid entries are 0
B
to 400 seconds. Deactivate by entering a value of
0 seconds.
Non-Volatile Memory (NVM)
A type of semiconductor memory that retains its
contents even though power is disconnected.
NVM contents can be changed during
Glossary
configuration unlike ROM which can be changed
only at time of instrument manufacture. NVM
stores configuration restart data.
Parallel
Simultaneous: said of data transmission on two or
more channels at the same time.
Polling Address
Address of the instrument. If the digital valve
controller is used in a point-to-point configuration,
set the polling address to 0. If it is used in a
multidrop configuration, or split range application,
set the polling address to a value from 0 to 15.
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Pressure Sensor
A FIELDVUE instrument internal device that
senses pneumatic pressure. The DVC6200 has
three pressure sensors: one to sense supply
pressure and two to sense the output pressures.
Primary Master
Masters are communicating devices. A primary
master is a communicating device permanently
wired to a field instrument. Typically, a
HART-compatible control system or a computer
running ValveLink software is the primary master.
In contrast, a secondary master is not often
permanently wired to a field instrument. The Field
Communicator or a computer running ValveLink
software communicating through a HART modem
could be considered a secondary master.
Note: If one type of master takes an instrument
Out Of Service, the same type must put it In
Service. For example, if a device set up as a
primary master takes an instrument Out Of
Service, a device set up as a primary master
must be used to place the instrument In Service.
Quick Opening
A valve flow characteristic where most of the
change in flow rate takes place for small amounts
of stem travel from the closed position. The flow
characteristic curve is basically linear through the
first 40 percent of stem travel. One of the input
characteristics available for a FIELDVUE
Instrument. See also, Equal Percentage and
Linear.
Random Access Memory (RAM)
A type of semiconductor memory that is normally
used by the microprocessor during normal
operation that permits rapid retrieval and storage
of programs and data. See also Read Only
Memory (ROM) and Non-Volatile Memory (NVM).
Rate
Amount of change in output proportional to the
rate of change in input.
Read-Only Memory (ROM)
A memory in which information is stored at the
time of instrument manufacture. You can
examine but not change ROM contents.
September 2010