TotalFlow XRC6490, User Manual

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TERM DEFINITION
Modbus Messaging structure developed and used to establish master-slave/client-
server communication between intelligent devices. Generic protocol supported
by most process automation vendors.
Modem Modulator-Demodulator. A device used to convert serial digital data from a
transmitting terminal to a signal suitable for transmission over a common
carrier, or to reconvert the transmitted signal to digital data for acceptance by a
receiving terminal.
Module Typically a board assembly and its associated mechanical parts, front panel,
optional shields, and so on. A module contains everything required to occupy
one or more slots in a mainframe.
Mol% See Mole Percent.
Mole Percent The number of moles of a component of a mixture divided by the total number
of moles in the mixture.
MRB Modbus Request Block. When requesting storage space after adding a new
Modbus application, the file is saved as a *.mrb file.
MRM Modbus Register Map. When requesting storage space after adding a new
Modbus register, the file is saved as a *.mrm file.
MS Milliseconds. One-thousandth of a second.
MSB Most Significant Byte
Mueller Bridge A high-accuracy bridge configuration used to measure three-wire RTD
thermometers.
Multiplex A technique which allows different input (or output) signals to use the same
lines at different times, controlled by an external signal. Multiplexing is used to
save on wiring and I/O ports.
Multi-tasking A property of an operating system in which several processes can be run
simultaneously.
Multi-tube Sites Locations where many flow tubes are all within a prescribed distance allowing
one flow meter with multitube capabilities, such as the XSeries product line, to
monitor and maintain flow records for each tube in one Flow Computer.
Multivariable Transducer Transducer supplying more than 1 variable. Totalflow uses this term to
encompass units that read Static Pressure, Differential Pressure. Historically
these units were coined AMU for Analog Measurement Unit. As a result of
advanced technology, the unit no longer functions as only an analog
measurement unit. Therefore the newer terminology, Multivariable Transducer,
more aptly describes the functionality of this design. The abbreviation IMV
refers to the Integral version of the multivariable. The abbreviation XIMV, refers
to the XSeries IMV version of the multivariable, which contains the circuitry as
part of the unit and the abbreviation IMVX, refers to the Explosion Proof IMV,
where the required circuitry resides on the Main Processor Board. See each
instance for additional explanation.
MW Acronym for Molecular Weight.
N2 A standard abbreviation for Nitrogen.
NAK See Negative Acknowledgement
NAMUR Normenarbeitsgemeinschaft für Mess- und Regeltechnik in der chemischen
Industrie (Standards study group for measurement and process control
technology in the chemical industry).
Natural Gas See Gas, Natural.
Natural Gas Distillate Material removed from natural gas at the "heavy end" portion; that is, aliphatic
compounds ranging from C4 to C8 (butanes and heavier).