Yokogawa YVP110 - Manual (Page 76)

<13. AO Function Block>
13-2
IM 21B04C01-01E
When any of the following status keeps for the
moment of time specified in FSTATE_TIME, the
block goes to the fault state and the mode changes
to LO mode.
1. Target mode is Cas, and the status of CAS_IN
is ‘Bad: No Comm’
2. Target mode is Cas, and the status of CAS_IN
is ‘Good: IFS’
3. Target mode is RCas, and the status of RCAS_
IN is ‘Good: IFS’
In LO mode, the block holds the output (OUT) or
outputs FSTATE_VAL, according to the setting of
IO_OPTS. The factory setting is to hold the output.
13.4 Backward Path
The valve position signal from the transducer block
is written to the parameter READBACK in the
AO block, then scaled based on XD_SCALE and
PV_SCALE to be converted to the process variable
PV. The value of PV is fed back to the PID block or
an upper-level system as the valve position signal
via the parameter BKCAL_OUT and RCAS_OUT.
If SIMULATE is set to 'Enable', the value of
SIMULATE.Simulate_Value is always set in
READBACK.
SIMULATE contains the following data:
Simulate Status: Status to be set in simulation
mode
Simulate Value: Value to be set in simulation
mode
Transducer Status: Status of input from
transducer
Transducer Value: Value of input from
transducer
Enable/Disable: Whether to enable (2) or
disable (1) simulation
13.5 IO_OPTS and STATUS_
OPTS
IO_OPTS and STATUS_OPTS are parameters that
stipulate options about block’s signal processing
and mode transitions. The settings of these options
are made by setting or resetting the respective bits:
on = true, off = false. Table 13.1 shows the options
available in IO_OPTS of the AO block.
Table 13.1 IO_OPTS of AO Block
Bit Meaning Description
0 Invert Not available
1 SP-PV Track in Man Equalizes SP to PV
when target is MAN
mode
2 Reserved Not available
3 SP-PV Track in LO Equalizes SP to PV in
LO mode.
4 SP Track retained target In LO mode, Equalizes
SP to RCAS_IN if target
mode is RCas and to
CAS_IN if target mode
is Cas.
5 Increase to close Inverts the signal while
it goes from SP through
OUT.
6 Fault State to value Uses a FSTATE_
VALUE in LO mode.
7 Use Fault State value
on restart
Uses a value preset
for fault state also at a
restart.
8 Target to Man if Fault
State activated
Sets the target mode to
Man upon activation of
the fault state.
9 Use PV for BKCAL_
OUT
Sets the value of PV
in BKCAL_OUT and
RCAS_OUT.
10 Low cutoff Not available
11 Reserved (SIS-Latch
Fstate)
Not available
12 Units Conversion Not available
Only the Propagate Fault Backward option is
available in STATUS_OPTS of the AO block.
Table 13.2 STATUS_OPTS of AO Block
Bit Meaning Description
4 Propagate
Fault
Backward
Stipulates the handling of the value,
data status and related alarm of
BKCAL_OUT and RCAS_OUT to be
performed.
If this option is true, then:
- Set the quality and sub-status
components of the status of
BKCAL_OUT to Bad and sensor
failure, respectively.
- Do nothing special for the
BKCAL_OUT value.
If this option is false, then:
- Set the quality and sub-status
components of the status of
BKCAL_OUT to Bad and non
specific, respectively.
- Generates a block alarm.