ABB SAM600-IO Protocol Manual page 35

1MRK 511 440-UEN A
Switchgear control unit SAM600-IO Version 2.2 IEC
Communication protocol manual
can be used as a background cycle to ensure that the process image in all
partners is the same.
• General interrogation
• A general interrogation is only done on request from a client. Not all
Data-sets may contain information which is needed for a general update
of the client. For example data with T(ransient) = TRUE are not part of a
GI. When the BRCB attribute general interrogation is set to TRUE a GI
request from the client will be handled. The report handler will transmit
all data defined in the Data-set with their actual values. The IEC 61850
standard defines that all buffered events shall be transmitted first before
the GI is started. A running GI shall be stopped and a new GI shall be
started, when a new GI request is received while a GI is running.
• Purge buffer (valid only for BRCB)
• This BRCB attribute can be used by a client to clean the event buffer
from old events. The events are discarded on request of the client. This
feature can be used to delete old events not transmitted to the client due
to stopped communication. After the link is reestablished the client can
decide to clean the buffer or to receive the history.
Trigger Options
IEC 61850 has defined in total five different TrgOp. Three of them belonging to
data attributes and marked per data attribute in the column TrgOp of the CDC
tables in part 7–3. The other two belonging to the configuration of control blocks.
• dchg = data-change
• Whenever a process value has changed its value either binary or a
measurement a transmission is done.
• qchg = quality change
• Looking to the possibilities of the quality data attribute type (q) any
changes in the quality description will be transmitted.
• dupd = data value update
• This trigger option give the possibility to define that a transmission
should be done on a condition which can be controlled by the
application.
• integrity
• This trigger forces the transmission of all process values defined in the
data set when a timer value (the integrity period) expires.
• general interrogation
• This trigger is forced by the clients (= station level IED; NCC gateway,
station HMI, ...). Normally a GI is asked for, when the client and the
server start or restart a session. When the client is able to receive the
actual values and when the logical device has scanned all process values
at least once, an image of the actual process signal status can be
transmitted to the client.
Data sets and control blocks
Section 6
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