Delta Controls 2HT User Manual
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002522-2HT 180210.doc
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LRL
Lower Range Limit
(pressure): The lowest measured value (pressure) that the
transmitter can sense, governed by the sensor.
LRV
Lower Range Value (pressure): Normally the lowest measured value (pressure) that
the analogue output (mA) of the transmitter can represent, but this may be reversed
with URV (pressure) for reverse analogue outputs (mA).
Master
Name used to describe any system that is in control of the slave field devices, HART
can support two masters, primary and secondary.
Message
A thirty two character field for additional information, name of installation engineer,
calibration technician etc.
MODEM
Modulator \ Demodulator: a device that converts serial computer signals to and from
an FSK (Frequency-Shift-Keyed) format.
Multidrop
This mode allows several field devices to share a common twisted pair of cables, a
total of 15 devices may use one cable.
Polling Address Unique number (1 - 15) used to identify an instrument when it is used in a multi-drop
circuit. Transmitters that are not used in a multi-drop configuration have a poll number
of zero.
Protocol
A set of rules or specifications that defines the structure of a communications
language.
PV
Prime Variable, in this case pressure.
Re-ranging
Function that allows the transmitters analogue output to be scaled differently from the
sensors upper and lower range limits (pressure).
SV
Secondary Variable, in this case temperature.
Slave
Name used to describe any device that will respond when requested to by a master.
Smart
A generic name used to describe any field device that can be configured from a
remote location, and shows some form of intelligence.
Span
Difference between the upper and lower range values (pressure).
Sputtering
A process used to bond glass and other materials to each other at a molecular level.
Tag
An eight character field for identification of the transmitter, this is used in long frame
format to build the unique identifier
URL
Upper Range Limit (pressure): The highest measured value (pressure) that the
transmitter can sense, governed by the sensor.
URV
Upper Range Value (pressure): Normally the highest measured value (pressure) that
the analogue output (mA) of the transmitter can represent, but this may be reversed
with LRV (pressure) for reversed analogue outputs( mA).