FOXBORO FCP270 FCP280

Description

• Foxboro Evo™ Control Editors, including the
Block Configurator, Programmable Logic
Block (PLB) Ladder Logic Editor, the
Sequence Block HLBL Editor, and the
Sequence Block SFC Editor
• The I/A Series® Configuration Component
(IACC) software
• Integrated Control Configurator
 Reuse of block configurations from one controller
to another.
OVERVIEW
The Foxboro Evo Integrated Control Software
provides a selection of continuous, sequential, and
ladder logic control domains. Each domain can be
used independently or integrated to meet specific
application requirements.
The control software provides the user with a
comprehensive control strategy and input/output
implementation for on/off control, timing, regulatory
and feedback applications. Implemented within a
block and parameter structure, the control software
provides the base for the integration of continuous,
ladder logic and sequential control with
programmable logic controller functionality.
The software control strategies allow you to mix and
match continuous and Programmable Logic Block
(PLB) capabilities with sequencing in the same
control scheme.
The process control domains – continuous,
sequential and batch, and ladder logic – execute in
any Foxboro control processor. The control software
running in a control processor provides the interface
to the Fieldbus subsystem and other I/O subsystems
through I/O blocks. These I/O blocks interface to the
specific applications executing in the Fieldbus
Modules (FBMs).
Access to the FBMs and associated devices (for
example, field sensors, actuators, Intelligent Field
Devices) is through the control software in the Field
Control Processor 280 (FCP280).
An optional fault-tolerant control processor
configuration, where two identical control processors
(Primary and Shadow) are running in parallel,
provides enhanced reliability to the control process.
For more information on the FCP280, refer to Field
Control Processor 280 (FCP280)
(PSS 31H-1B11 B3).
EXACT Multivariable Control (EXACT MV)
The Foxboro Evo EXACT Multivariable Controller
(EXACT MV) with Adaptive Multivariable Control
provides feedforward tuning of up to four variables,
plus tuning of the feedback controller. On the low
end, it provides superior control of a single difficult to
control loop with multiple load upsets. On the high
end, multiple blocks can interconnect interactive
signals among the loops to improve control for up to
five interacting control loops in a five by five cross
coupled scheme.
At the core of the EXACT MV is an advanced control
block, PIDA, for advanced Proportional-IntegralDerivative control. However, the formula for adaptive
multivariable capability resides in the feedback tuning
extender block, FBTUNE, and the feedforward tuning
block, FFTUNE.
CONTROL SOFTWARE CONCEPTS
Figure 1 shows the integration of continuous control,
ladder logic, and sequential control in a single control
processor. A block is a member of a set of algorithms
that perform a certain control task. The Foxboro Evo
control blocks also support user-defined arithmetic
and Boolean logic functions, alarm detection and
reporting, and shared variables, which are global
variables that allow data to be shared across
applications within the Foxboro Evo Process
Automation System.

At the beginning of block processing, I/O data is read
from each Fieldbus Module, for both input and
output channels. Data is read at the ECB scan period
specified for that module. However, data cannot be
read faster than the BPC. At the end of block
processing, process outputs are written to each of
the Fieldbus Modules.
Station Block
Each control processor contains a station block
automatically created to provide global data on
control processor system functions. The station
block contains information such as:
 Continuous block processing load
 Total CP load
 Basic processing cycles and CP overruns
 Number of bytes of dynamic free memory
 Number of peer-to-peer connections
 Sequence processing load
 I/O scan load
 OM scan load
 Idle time
 Station alarm groups
 Configuration security option.
Previous CPs only supported one I/O channel to an
HDLC fieldbus (which provides communication to a
chain of Fieldbus Modules) directly, or used external
hardware, such as the FEM100 (discussed in
PSS 21H-2Y14 B4) to support up to four I/O
channels. However, the FCP280 supports four I/O
channels directly, without the use of such external
hardware.
Every HDLC fieldbus’ channel requires a software
driver in the CP called a Primary ECB. Thus, the
FCP280’s Compound has four Primary ECBs – one
for each channel – through which the station block
directs all communications. Each of its FBM’s ECBs
must be assigned to the Primary ECB for the channel
on which their FBM resides via a new parameter
added to them called “CHAN”.
CONTROL CONFIGURATION CONCEPTS
The Foxboro Evo control blocks are configured from
the Process Engineer’s Environment, which provides
access to the Block Configurator, Integrated Control
Configurator (ICC), or I/A Series Configuration
Component (IACC).