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Figure
9
shows that the first step to be performed is the transmission of a POST
request to a specific Web Service Interface, containing (in JSON format) the identifier of
the data attribute and the sampling interval desired (the information about the Broker
is not present due to the lack of space). According to this request, the IEC 61850 Client
will proceed to read the requested value from the IEC 61850 Server using the IEC 61850
standard communication services. Figure
9
shows steps 2 and 3, relevant to the request of
the current value from the server and the transmission of the requested value to the client,
respectively. These steps are repeated over time on the basis of the interval specified by the
Web User (only the current single value is retrieved if the interval value is “0”, as noted
previously). For each value retrieved from the server, the Middleware creates a JSON file
containing the value and the MQTT Publisher will send an MQTT frame containing this
JSON file as the payload (step 4). The next step (step 5) is the transmission of the topic to be
used by the Web User to retrieve the requested value(s) from the Broker. The Web User will
subscribe to the Broker (step 6), and through this subscription the Web User will receive
from the Broker the single value or the values updated according to the frequency specified
(step 7); Figure
9
refers to this last scenario, noting the values sampled each 500 ms.
4.6. Updating Values in the IEC 61850 Server
The Web User may need to update the value of a data attribute in an IEC 61850
Server. A service was defined to achieve this goal. A POST request must be issued at a
particular Web Service Interface, including the identifier of the data attribute to update and
the relevant value. The Web User will receive a POST response to confirm the updating
operation.
Figure
10
shows the several steps needed to accomplish the Web User’s request to
update the value of the BDA identified by “BCU1M19/C1/LBAYMMXU1/A/phsB/db”
(shown in Figure
3
).
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attribute and the sampling interval desired (the information about the Broker is not present
due to the lack of space). According to this request, the IEC 61850 Client will proceed to read
the requested value from the IEC 61850 Server using the IEC 61850 standard communication
services. Figure 9 shows steps 2 and 3, relevant to the request of the current value from the
server and the transmission of the requested value to the client, respectively. These steps are
repeated over time on the basis of the interval specified by the Web User (only the current
single value is retrieved if the interval value is “0”, as noted previously). For each value
retrieved from the server, the Middleware creates a JSON file containing the value and the
MQTT Publisher will send an MQTT frame containing this JSON file as the payload (step
4). The next step (step 5) is the transmission of the topic to be used by the Web User to
retrieve the requested value(s) from the Broker. The Web User will subscribe to the Broker
(step 6), and through this subscription the Web User will receive from the Broker the single
value or the values updated according to the frequency specified (step 7); Figure 9 refers to
this last scenario, noting the values sampled each 500 ms.
4.6. Updating Values in the IEC 61850 Server
The Web User may need to update the value of a data attribute in an IEC 61850
Server. A service was defined to achieve this goal. A POST request must be issued at a
particular Web Service Interface, including the identifier of the data attribute to update
and the relevant value. The Web User will receive a POST response to confirm the updat-
ing operation.
Figure 10 shows the several steps needed to accomplish the Web User’s request to
update the value of the BDA identified by “BCU1M19/C1/LBAYMMXU1/A/phsB/db”
(shown in Figure 3).
