QQ
| BIT Value
| Define
| Description
|
0
| 000000LL
| Non-specific
| The value is bad but no specific reason is known
|
-
| - LL
| Configuration Error
| There is some server specific problem with the configuration. For example the
item is question has been deleted from the configuration.
|
-
| 000010LL
| Not Connected
| The input is required to be logically connected to something but is not. This
quality may reflect that no value is available at this time, for reasons like
the value may have not been provided by the data source.
|
-
| 000011LL
| Device Failure
| A device failure has been detected
|
-
| 000100LL
| Sensor Failure
| A sensor failure had been detected (the 'Limits' field can provide additional
diagnostic information in some situations.)
|
-
| 000101LL
| Last Known Value
| Communications have failed. However, the last known value is available. Note
that the 'age' of the value may be determined from the TIMESTAMP in the OPCITEMSTATE.
|
-
| 000110LL
| Comm Failure
| Communications have failed. There is no last known value is available.
|
-
| 000111LL
| Out of Service
| The block is off scan or otherwise locked This quality is also used when the
active state of the item or the group containing the item is InActive.
|
- 15
|
| N/A
| Not used by OPC
|
QQ
| BIT Value
| Define
| Description
|
0
| 010000LL
| Non-specific
| There is no specific reason why the value is uncertain.
|
-
| 010001LL
| Last Usable Value
| Whatever was writing this value has stopped doing so. The returned value
should be regarded as 'stale'. Note that this differs from a BAD value with
Substatus 5 (Last Known Value). That status is associated specifically with a
detectable communications error on a 'fetched' value. This error is associated with the
failure of some external source to 'put' something into the value within an
acceptable period of time. Note that the 'age' of the value can be determined from
the TIMESTAMP in OPCITEMSTATE.
|
- 3
|
| N/A
| Not used by OPC
|
4
| 010100LL
| Sensor Not Accurate
| Either the value has 'pegged' at one of the sensor limits (in which case the
limit field should be set to 1 or 2) or the sensor is otherwise known to be out
of calibration via some form of internal diagnostics (in which case the limit
field should be 0).
|
5
| 010101LL
| Engineering Units Exceeded
| The returned value is outside the limits defined for this parameter. Note that
in this case (per the Fieldbus Specification) the 'Limits' field indicates
which limit has been exceeded but does NOT necessarily imply that the value cannot
move farther out of range.
|
6
| 010110LL
| Sub-Normal
| The value is derived from multiple sources and has less than the required
number of Good sources.
|
7-15
|
| N/A
| Not used by OPC
|