Explanation Of Modes - Emerson Fisher Fieldvue DVC6030f Instruction Manual

DVC6000f Series
Table A-1. Block Modes
Block
Resource Auto and OOS
Transducer Auto, Manual, and OOS
AO RCas, Cas, Auto, Man, LO
ROut, RCas, Cas, Auto, Man, LO
PID
OOS
ISEL Auto, Man and OOS
OS IMan, Auto, Cas and OOS
AI Man, Auto, and OOS
MAI Man, Auto, and OOS
DO RCas, Cas, Auto, Man, LO
DI Auto, Man, and OOS
1. This mode cannot be specified as a target mode.
modify the Target or Normal mode. At this time these
attributes are tested against the Permitted modes,
thus the user cannot change the Normal or Target
modes to what was formerly permitted.
D Normal mode— The normal mode is the mode
the block should be in during normal operating
conditions. The normal mode is set by the user or host
system and can only be set to a permitted mode (see
permitted mode). The user or host system can
compare the actual mode to the normal mode and,
based on the results, determine if the block is
operating normally.
Table A-1 lists the modes supported by each block
contained in the digital valve controller.
Changing the block mode requires accessing the
Block Mode parameter. For information on using the
host system to change the block mode via this
parameter, see the appropriate host documentation.
A
A downstream block changing to Out of
Service impacts the mode of the
upstream block. Refer to the block
hierarchy in figure A-2.

Explanation of Modes

Out of Service (OOS)—The functions performed by
the block are not executed. If the block has any
outputs, these typically do not update and the status of
any values passed to downstream blocks will be
"BAD". To make changes to some of the parameters
in a block requires that the block be Out of Service.
Initialization Manual (IMan)—Only the AO, DO and
PID blocks support this mode. When one of these
blocks detects a loss of a correct path to the
A-4
Supported Mode Values
(1) (1)
, IMan , and OOS
(1) (1)
, IMan , and
(1) (1)
, IMan , and OOS
Note
RESOURCE
BLOCK
ANALOG OUTPUT
PID BLOCK
(AO) BLOCK
NOTES:
1. CHANGING THE RESOURCE BLOCK TO OUT OF SERVICE CHANGES ALL
FUNCTION BLOCKS TO OUT OF SERVICE, BUT DOES NOT AFFECT THE
TRANSDUCER BLOCK.
2. CHANGING A DOWNSTREAM BLOCK TO OUT OF SERVICE AFFECTS THE UP
STREAM BLOCK. FOR EXAMPLE: WHEN THE TRANSDUCER BLOCK IS OUT OF
SERVICE, THE AO BLOCK MODE WILL CHANGE TO IMAN (INITIALIZE MANUAL).
Figure A-2. Digital Valve Controller Block Hierarchy Example
downstream block (such as when the downstream
block is in the OOS, Man, or LO mode), it enters the
IMan mode. For example, when the transducer block
enters the OOS mode, the AO block enters the IMan
mode.
Local Override (LO)—Only the AO, DO and PID
blocks support this mode. If the PID block enters the
LO mode, the block output follows the tracking value
(TRK_VAL), if external tracking is enabled by
TRK_IN_D. In the AO and DO block, the block enters
LO mode when the block detects that fault state is
active. In this case, the output is determined by the
selection for I/O_OPTS.
Manual (Man)—If the data status of a function block's
input is bad or its target mode is Man, the block enters
the manual mode. In this mode, the function block
does not update its OUT value. If the target is Man,
the user may write a desired value to the output.
Automatic (Auto)—The block performs the specified
calculations based on the local set point and outputs
the result, independently without interfacing with
another block. The user can write to the set point of a
block in this mode. Any block outputs continue to
update.
Cascade (Cas)—The block performs the specified
calculations based on the set point from another block
via the cascade input parameter and outputs the
result. Any block outputs continue to update.
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.
TRANSDUCER
BLOCK
March 2006