3.4.4.1.6 Generating Datasets, Reporting
The specific project related feature of the P634’s communications behavior is
determined by the configuration of datasets, reports and high priority
transmission methods. A piece of information must be included in a dataset so as
to be transmitted as a signal. A dataset is a list to transmit certain data objects.
The selection of data objects and the resulting length of the dataset is
determined by the application; merely the GOOSE capacity, i.e. the maximum
size of a dataset to be transmitted by GOOSE, is limited to 1500 bytes.
It is not possible to read the IEC configuration back from the P634 if the “Dataset”
sizes exceed the GOOSE size limit significantly. Therefore it is recommended to
limit the “Dataset” size(s) to 100% of the GOOSE capacity. Too large a dataset can
spoil IEC 61850 communication. Hence, the dataset size limit of 100% of the
GOOSE capacity should not be exceeded, neither for GOOSE nor for reports.
Data objects provided by the P634 are available for selection with a structure as
specified by IEC 61850. Within the quality descriptor for each piece of
information the invalid bit and the test bit are served according to the P634’s
state; the other attributes are not set. Any number of datasets may be created
with the IED Configurator. Saving datasets at System\LLN0 is compulsory. The
knowledge of dataset content is imperative for decoding and evaluating received
signals. Configuration files possess a listing of all datasets with a description of
all data objects included.
Next to their use with high priority transmission methods (see Section 3.4.4.1.10,
(p. 3-27)) datasets are used mainly for reporting. The P634 provides up to
sixteen unbuffered reports and eight buffered reports independent of the number
of clients logged-on. Management is arranged into sixteen Unbuffered Report
Control Blocks (urcbA to urcbP) and eight Buffered Report Control Blocks (brcbA
to brcbH). Whereas with unbuffered reporting pieces of information may be lost
during a communications failure, the buffered report control blocks support a
buffered transmission which is required for the uninterrupted writing of events. A
pre-defined dataset may be assigned to each report which will then determine
which data object will be transmitted with the relevant report. Assigning datasets
is not limited; the same dataset may be referenced in various reports or even in
GOOSEs.
The P634 can serve up to sixteen clients. Each client can log-on to any number of
available reports. One unbuffered report can be allocated to max. 8 clients, and
one buffered report can be allocated to max. 4 clients. A client is then able to
activate the wanted report for himself and to set the transmission behavior to his
requirements. The system concept with intended clients must be taken into
account when datasets are assigned to the reports.
Reports are not received by the P634.
3.4.4.1.7 Transmitting Modeled Signals Not Provided by the IEC 61850 Data Model
In addition to the information included in the IEC 61850 data model an optional
number of up to 16 signals can be selected from all the signals available in the
P634 to be transmitted via reporting. A selection of state signals (shuttling to
communications) is made by setting IEC: SigGGIO1 selection. The data
object indexes defined for SigGGIO1 must follow the sequence given for the ‘m
out of n’ selection for the state signals. The indexes SigGGIO1.ST.ind1 to
SigGGIO1.ST.ind16 may then be included in the datasets just as the other data
objects.
3 Operation
P634
P634/EN M/R-42-A // P634‑311‑653 3-25
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