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Advanced Diagnostics
Appendix
8.2.4
Digital input (DI) Function Block
Parameters
Parameter
ST_REV
TAG_DESC
STRATEGY
ALERT_KEY
MODE_BLK
BLOCK_ERR
PV_D
OUT_D
SIMULATE_D
XD_STATE
GRANT_DENY
IO_OPTS
STATUS_OPTS
CHANNEL
PV_FTIME
FIELD_VAL_D
Char.
Description
During each writing process to a parameter marked
with "S", the parameter ST_REV is increased by 1.
W, S
Via this parameter, a tag (measuring point designa-
tion) can be assigned to the valve interface in the
plant or process.
W, S
The strategy field can be used to identify comprising
blocks. This data is not controlled or used by the
block.
W, S
Identification number of the plant component. This
information can be used by the control PC, e.g., to
sort alarms. Valid values are 1 ... 65536.
W, S
Displays the current, allowed, normal mode and the
target mode of the block. The target mode can be set
to the values "Auto", "Man" or "Out of Service".
Displays diagnostic messages of the block.
Channel value with optional inversion (IO_OPTS)
and filtering applied to it (PV_FTIME).
W, Man
The actual output value. When the block is in AUTO
mode, this is equal to PV_D. If the block is in manual
mode, the parameter is writeable.
W, S, OOS
Using this structure, the simulation can be activated
or deactivated. If the simulation is activated, this
parameter determines FIELD_VAL_D. The simula-
tion can only be activated with the associated
switch 1 ON.
W, S
Used by some PCS to assign texts to the numerical
values of FIELD_VAL_D.
W
Depending on the PCS in use, the parameter regu-
lates the access rights between PCS and local oper-
ator workstations for some control systems.
W, S, OOS
Option which enables the user to adapt the block
algorithm to the task of the block. This option is:
Invert.
PV_D is calculated as follows: A Boolean negation of
FIELD_Val_D is carried out i.e., PV_D becomes 1 if
FIELD_VAL_D is 0. If FIELD_VAL_D is greater than
0, then PV_D becomes 0.
W, S, OOS
Option that enables the user to adapt the block status
processing to the task of the block. This option is:
Propagate Fault Forward.
If this option is used, the function block does not trig-
ger an alarm itself if the status of PV_D becomes
"Bad". Instead, the status, including substatus, is
passed on via OUT_D.
W, S, OOS
The number of the logical hardware channel that is
connected to this I/O block. This information defines
the signal converter to be used going to or from the
physical world. See chapter 8.3
W, S
Time constant of a single exponential filter for the pri-
mary variable (PV) in seconds.
Raw value of the field device digital input, with a sta-
tus reflecting the signal converter condition.
163
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