Backup Link Active Scheduler (Las); Profibus Pa (Output Code W) - Emerson Rosemount 2051 Reference Manual

Specifications and Reference Data
November 2016
F Fieldbus parameters
OUNDATION
Schedule entries
Links
Virtual communications relationships (VCR) 20 (max.)
Standard function blocks
Resource block
The resource block contains diagnostic, hardware and
electronics information. There are no linkable inputs or
outputs to the resource block.
Sensor Transducer Block
The Sensor Transducer Block contains sensor
information including the sensor diagnostics and the
ability to trim the pressure sensor or recall factory
calibration.
LCD display Transducer Block
The LCD display Transducer Block is used to configure
the LCD display meter.
Analog input block
The analog input (AI) function block processes the
measurements from the sensor and makes them
available to other function blocks. The output value
from the AI Block is in engineering units and contains a
status indicating the quality of the measurement. The
AI Block is widely used for scaling functionality.
Note
The channel, Set XD_Scale, Set L_Type, and sometimes Set
Out_Scale are typically configured by instrument
personnel. Other AI Block parameters, block links, and
schedule are typically configured by the control systems
configuration engineer.
Input selector block
The input selector (ISEL) function block can be used to
select the first good, Hot Backup
minimum, or average of as many as eight input values
and place it at the output. The block supports signal
status propagation.
Integrator block
The integrator (INT) function block integrates one or
two variables over time. The block compares the
integrated or accumulated value to pre-trip and trip
limits and generates discrete output signals when the
limits are reached.
The Integrator Block is used as a totalizer. This block will
accept up to two inputs, has six options how to totalize
the inputs, and two trip outputs.
66
7 (max.)
25 (max.)
™
, maximum,
Arithmetic block
The arithmetic (ARTH) function block provides the
ability to configure a range extension function for a
primary input. It can also be used to compute nine
different arithmetic functions including flow with
partial density compensation, electronic remote seals,
hydrostatic tank gauging, ratio control and others.
Signal characterizer block
The signal characterizer (SGCR) function block
characterizes or approximates any function that defines
an input/output relationship. The function is defined by
configuring as many as twenty X,Y coordinates. The
block interpolates an output value for a given input
value using the curve defined by the configured
coordinates. Two separate analog input signals can be
processed simultaneously to give two corresponding
separate output values using the same defined curve.
PID block
The PID function block combines all of the necessary
logic to perform proportional/integral/derivative (PID)
control. The block supports mode control, signal
scaling and limiting, feed forward control, override
tracking, alarm limit detection, and signal status
propagation.
Control selector block
The control selector function block selects one of two
or three inputs to be the output. The inputs are
normally connected to the outputs of PID or other
function blocks. One of the inputs would be considered
Normal and the other two overrides.
Output splitter block
The output splitter function block provides the
capability to drive two control outputs from a single
input. It takes the output of one PID or other control
block to control two valves or other actuators.
A.2.5 Backup link active scheduler (LAS)
The transmitter can function as a LAS if the current link
master device fails or is removed from the segment.
A.2.6 PROFIBUS PA (output code W)
Profile version
3.02
Power supply
External power supply required; transmitters operate on
9.0 to 32.0 Vdc transmitter terminal voltage for non-I.S.
applications, 9.0 to 30 Vdc for entity model intrinsically safe
applications and 9.0 to 17.5 Vdc for FISCO intrinsically safe
applications.
Reference Manual
00809-0300-4101, Rev BB
Specifications and Reference Data