KROHNE IFC 090 i Converter FOUNDATION FIELDBUS - Manual (Page 38)

Supplementary Documentation Page 38 of 44
IFC090, IFC090 i with FF
IFC090-FF Configuration
IFC090 FF 01/2006
KROHNE Messtechnik GmbH & Co. KG · Ludwig-Krohne-Str. 5 ‚ D-47058 Duisburg
Tel.: 0203-301 309 ‚ Fax: 0203-301389 · E-mail: [email protected]
Down demand
Only one kind of reset is possible: Operator Reset. See ‘Down auto‘ above for details.
Periodic
In difference to the integration types so far, this type does not support resets depending on totalization values
and/or operator signals. The periodic integration type also performs a automatic reset, but this reset is caused
by a elapsed time duration. If since the last reset the time specified in CLOCK_PER is elapsed, the totalization
is reset to zero (0.0).
An operator based reset is not possible; in contrast a write to OP_CMD_INT or RESET_IN would cause a
‘Wrong Mode for Request’ error.
Demand
Automatic resets are not performed with this setting, only operator controlled resets are possible. A write to
OP_CMD_INT or RESET_IN, respectively are the only possibilities to cause a totalization reset.
Periodic & Demand
This combines the reset possibilities of settings ‘Periodic’ and ‘Demand’, i.e. time based and operator resets are
possible.
Normally, the reset residual (i.e. the absolute difference between the reset point and the current value just
before the reset) isn’t considered in any way. But in some application it may be important, to carry this residual
to the next integration cycle. Enable option ‘Carry’ (i.e. set true) in parameter INTEG_OPTS. In order to
configure how to carry over the residual,
Common to all resets is the handling of the following parameters:
STOTAL
Snapshot of the totalization value just before the last reset.
SRTOTAL
Snapshot of the RTOTAL, i.e. input values with BAD status, just before the last reset.
SSP
Snapshot of the Set Point, i.e. setting of TOTAL_SP, just before the last reset. Useful, if TOTAL_SP was
changed since the last reset.
N_RESET
Number of resets. Useful to verify if a reset happened since the last reset.
RESET_CONFIRM
Used by control systems to confirm a reset, if confirmation is configured.
To configure reset confirmation, enable option ‘Confirm reset’ (i.e. set to true) in parameter INTEG_OPTS.