Fisher FIELDVUEDVC6200f Instruction Manual page 211

Instruction Manual
D103412X012
D Out of Service (OOS)—The block is not processed. The output channel is maintained at the last value and the status
of OUT [9] is set to Bad: Out of Service. The BLOCK_ERR [6] attribute shows Out of Service.
D Initialization Manual (Iman)—The path to the output hardware is broken and the AO block output will remain at the
last position. This means the transducer block mode is Out of Service or Manual or configured to respond to the DO
block.
D Local Override (LO)—The output of the block is not responding to inputs because the fault state action is active or
the latch is engaged. OUT [9] freezes or goes to value per IO_OPTS [14].
The target mode of the block may be restricted to one or more of the following modes: Man, Auto, Cas, RCas, or OOS.
Mode Handling
Shed Options—RCAS Mode Only
Automatically changing through the permitted modes when starting from a remote mode, fall from (or shed) or climb
to a remote mode is determined by the parameter SHED_OPT [27]. A block climbs and sheds through the same path.
For example, if SHED_OPT [27] specifies that a block should shed to Auto, then, if the block target mode is set to RCas,
the block goes through Auto on the way to RCas.
When the block is in Cas mode and the CAS_IN [17] input goes bad, the block sheds mode to the next lower permitted
mode.
You can configure the shed option as follows:
Shed With Return Options
Remote cascade connection failure shifts actual mode but keeps trying to restore remote cascade (in other words, the
remote cascade target mode stays in effect).
Note
During Shed with Return Options, the actual mode is changed, while the target mode stays the same.
Normal—On failure of a remote cascade connection the block attempts to attain the highest permitted non‐remote
mode until remote cascade is restored. Cas is the highest permitted non‐remote mode and Auto is is the next
permitted non‐remote mode. If Cas or Auto are not available, the block will shed by default to Man.
Retained Target—The retained target mode is the previous target mode before it was changed to RCAS or ROUT. On
failure of a remote cascade connection the block attempts to attain the retained target mode.
Auto—On failure of a remote cascade connection the block attempts to attain Auto, if permitted, until remote cascade
is restored.
Man—On failure of a remote cascade connection the block sheds to Man until a remote cascade connection is
restored.
Shed With No Return Options
Note
During Shed with No Return Options, the target mode is changed, while the actual mode stays the same.
DVC6200f Digital Valve Controller
AO Function Block
February 2017
211