The configuration model defines different parameters that influence the information flow from Publisher to Subscriber in the case of a Bad Value Status or other error situations. Figure 24 depicts the parameters and the information flow inside a Publisher and inside a Subscriber.
The parameters and behaviour relevant for the encoding of a DataSetMessage on the Publisher side and the decoding of the DataSetMessage on the Subscriber side are defined in 6.2.4.2 together with the DataSetFieldContentMask.
Figure 24 – PubSub information flow
The mapping of source value and status to the DataSet in the Publisher depends on the substitute value. The dependencies are defined in Table 70.
Table 70 – Source to message input mapping
Source |
Substitute Value |
DataSet Publisher side |
||
Value(b) |
Status (a) |
Value |
Status (a) |
|
Value 1 |
Good_* |
Value 2
|
Value 1 |
Good_* |
Value 1 |
Uncertain_* |
Value 1 |
Uncertain_* |
|
Ignored |
Bad_* |
Value 2 |
Uncertain_SubstituteValue |
|
Value 1 |
Good_* |
Null |
Value 1 |
Good_* |
Value 1 |
Uncertain_* |
Value 1 |
Uncertain_* |
|
Ignored |
Bad_* |
Null |
Bad_* |
|
(a)If no specific StatusCode is used, the grouping into severity Good, Uncertain or Bad is used. In this case, the resulting Status matches the input Status. (b)Any error that happens during processing of source value e.g. DataType does not match DataSetField should be treated like a Bad StatusCode received from the source. |
The mapping of the decoded DataSet on the Subscriber side to the value and status of the target Variable depends on the override value. The dependencies are defined in Table 71.
Table 71 – Message output to target mapping
Decoded DataSet Subscriber |
Override Value Handling Enum |
Override Value |
Reader State |
Target |
||
Value |
Status (a) |
Value |
Status (a) |
|||
Value 1 |
Good_* |
OverrideValue
|
Value 2 |
Operational |
Value 1 |
Good_* |
Value 1 |
Uncertain_* |
Value 1 |
Uncertain_* |
|||
Ignored |
Bad_* |
Value 2 |
Good_LocalOverride |
|||
Value 1 |
Good_* |
LastUsableValue |
Ignored |
Value 1 |
Good_* |
|
Value 1 |
Uncertain_* |
Value 1 |
Uncertain_* |
|||
Ignored |
Bad_* |
LastValue (b) |
Uncertain_LastUsableValue |
|||
Value 1 |
Good_* |
Disabled |
Ignored |
Value 1 |
Good_* |
|
Value 1 |
Uncertain_* |
Value 1 |
Uncertain_* |
|||
Ignored |
Bad_* |
Null |
Bad_* |
|||
No message received. The target values are updated once after a reader state change. |
OverrideValue |
Value 2 |
Disabled Paused |
Value 2 |
Good_LocalOverride |
LastUsableValue |
Ignored |
LastValue (b) |
Uncertain_LastUsableValue |
Disabled |
Ignored |
Null |
Bad_OutOfService |
OverrideValue |
Value 2 |
Error |
Value 2 |
Good_LocalOverride |
LastUsableValue |
Ignored |
LastValue (b) |
Uncertain_LastUsableValue |
Disabled |
Ignored |
Null |
Bad_NoCommunication |
(a)If no specific StatusCode is used, the grouping into severity Good, Uncertain or Bad is used. In this case, the resulting Status matches the input Status. (b)The last value is either the last received value or the default value for the data type if there was never a value received before. |
If one of the target Variables in the SubscribedDataSet does not allow writing of the StatusCode and the OverrideValueHandling is set to Disabled, the DataSetReader shall indicate the configuration error by setting the DataSetReader state to Error. In all other configurations of OverrideValueHandling when the target Variable does not allow writing of the StatusCode, only the Value is transferred to the target Variable.
If a target Variable in the SubscribedDataSet does not allow writing of timestamp, any received timestamp shall not be used and only the received value shall be written to the target Variable.