Examples Of Modes For Various Operation Statuses; Device Descriptions; Transducer Block Status And Limit Propagation - Fisher FIELDVUEDVC6200f Instruction Manual

Instruction Manual
D103412X012
Remote Output (ROut)—The block outputs are set to the value of the remote output parameter that is written by a
host computer or others. To prevent a sudden change in output, the block's calculations are initialized when a change
in mode occurs.
Remote Cascade (RCas)—The block performs the specified calculations based on a set point from a host computer or
others via the remote cascade input and outputs the result. If the block has any outputs, these continue to update.
Examples of Modes for Various Operational Statuses
Table D‐2 shows examples of block mode combinations in a digital valve controller (however it does not show all
combinations). When a block changes mode or the data status signal changes for some reason, the other blocks
connected to that block identify the change by detecting the change in status of an input signal, and change their
modes too. For example, when the data status of BKCAL_IN in a PID block changes to bad, the PID block automatically
changes its mode to Iman to initialize the control of its downstream block.
Table D‐2. Examples of Block Mode Combinations and Operational statuses for an Instrument with Standard Control
Operational Status
Initial Setup and calibration
Modification of some transducer block parameters
Constant valve position control
PID Single‐loop control
PID Cascade‐loop control
1. TB=Transducer Block
The respective modes to which each block should enter upon occurrence of a communication error and at a restart,
and the handling of signals in each mode may be defined in the block's option parameters such as IO_OPTS and
STATUS_OPTS. For details, see the detailed descriptions of each function block.

Device Descriptions

Device Descriptions are specified definitions that are associated with blocks. Device descriptions provide for the
definition and description of blocks and their parameters.
Device descriptions may also include a set of processing routines called Methods. Methods provide a procedure for
accessing and manipulating a series of parameters within a device, such as for setup and calibration. Methods are used
for a variety of functions including automatic calibration, setting protection and setting up the instrument. These
Methods are a predetermined sequence of steps for information required to setup, calibrate, and perform other
functions on the instrument.

Transducer Block Status and Limit Propagation

Every F Fieldbus parameter has a value and a status. The status attribute is divided into three components:
OUNDATION
Quality, Quality substatus, and a Limit. The Quality can be Good (Cascade), Good (Non‐Cascade), Uncertain, and Bad.
Each quality can have a substatus as shown in table D‐3. Each status attribute also has four possible limit states: Not
limited, Low limited, High limited, and Constant. Refer to the Fieldbus Foundation specifications for a more detailed
description. The following describes how the transducer block passes status information to the AO block. For
information on status handling by the function blocks within the digital valve controller, refer to the Detailed Setup
section.
Blocks
PID
- - -
- - -
- - -
Auto
Primary PID, Auto
Secondary PID, Cas
DVC6200f Digital Valve Controller
F Fieldbus Communication
OUNDATION
AO
OOS
IMan
Auto
Cas
Cas
February 2017
(1)
TB
OOS
Manual
Auto
Auto
Auto
201