Supplementary Documentation
Page 20 of 44
IFC090, IFC090 i with FF
IFC090-FF Block Description
IFC090 FF 01/2005
KROHNE Messtechnik GmbH & Co. KG · Ludwig-Krohne-Str. 5
D-47058 Duisburg
Tel.: 0203-301 309
Fax: 0203-301389 · E-mail: [email protected]
Parameter
Access
Description
MODE_BLK Mix
Display of the current (
actual
), desired (
target
), possible (
permitted
) and
normal
modes of the Analog Input Block. By writing a permitted value to the
target field, you can control the execution modes of the block. The following
block modes are allowed for the IFC090-FF Analog Input Block:
Automatic Mode (AUTO)
In this mode, the Analog Input Block performs its functional computations
in accordance with its configuration automatically. Measurement value
deliverance and alarm handling are active.
Manual
(MAN)
In difference to AUTO mode, the block doesn’t perform an automatic
deliverance of valid measurement values, but freezes the measurement
to the last one obtained in Auto mode. The
OUT
status limit switches to
constant. In this mode it is possible to write to the
OUT
value an arbitrary
value to test blocks that use this
OUT
value as input. The alarm model
works in the same way as in Auto mode.
Out of Service (OOS)
In this mode, the Analog Input Block stops its execution. No valid
measurement value will be delivered, what can be seen at the status of
OUT
(Bad:OutOfService:NotLimited)
.
OUT R/W
The primary analog value and status calculated as a result of executing the
block.
In Auto mode of this block, the value and its status is automatically
calculated on the base of the channel value obtained from the Transducer
Block and calculation methods of the Analog Input Block. In Man mode it is
possible to write to this value to specify a known, given value that can be
used to test the correct operation of other downstream function blocks.
OUT_SCALE R/W
Together with parameter
XD_SCALE
, OUT_SCALE is one of the two main
scaling parameters. It can’t be seen isolated. These two parameters specify
a mapping function from the channel value obtained from the. See 5.3.2 for
details.
PV R
Value and status of the process value with same unit as
OUT_SCALE
. PV is
the result after performing the linearization (see
L_TYPE
), the low cutoff (see
LOW_CUT, IO_OPTS
) and the filtering (see
PV_FTIME
).
PV_FTIME R/W
Time constant of the single exponential filter for the
PV
in seconds.
SIMULATE R/W
Normally, SIMULATE is used to perform a channel value and status
simulation, i.e. instead of using the channel value obtained from the
Transducer Block, the user would be able to simulate a distinct (constant)
value and status as it comes from the Transducer. This is intensively used
while interoperability testing at the Fieldbus Foundation. Since it has no
practical use, this parameter isn’t supported by the IFC090-FF.
ST_REV R
Static data revision counter. ST_REV will be incremented if a static Analog
Input Block parameter has changed. By checking this parameter, control
systems are able to realize if a static parameter has changed its value
without checking all static parameters all the time.
