Schweitzer Engineering Laboratories SEL-351-5, Instruction Manual

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H.6
SEL-351-5, -6, -7 Relay Instruction Manual
Date Code 20070117
Distributed Network Protocol
Data Access Method
Data Access Method
Based on the capabilities of the system, it is necessary to determine which
method is desired to retrieve data on the DNP connection.
Table H.3
summarizes the main options, listed from least to most efficient, and
corresponding key related settings are indicated.
Table H.3 Data Access Methods
Data Retrieval
Method
Description
Relevant SEL-351 DNP
(Standard) Settings
Relevant SEL-351 DNPE
(Extended) Settings
Polled Static The master polls
for static (Class 0) data only. Set ECLASS = 0,
Set UNSOL = N. Set CLASSA = 0,
Set CLASSB = 0,
Set CLASSC = 0,
Set UNSOL = N.
Polled Report-by-
Exception The master polls
frequently for event data
and occasionally for static data. Set ECLASS to a non-zero value,
Set UNSOL = N. Set CLASSA = to a non-zero value,
Set CLASSB = to a non-zero value,
Set CLASSC = to a non-zero value.
Set UNSOL = N.
Unsolicited
Report-by-
Exception The slave devices send
unsolicited event data to the
master, and the master occasionally
sends integrity polls for static data. Set ECLASS to a non-zero value,
Set UNSOL = Y,
Set NUMEVE and AGEEVE
according to how often
messages are desired to be sent. Set CLASSA = to a non-zero value,
Set CLASSB = to a non-zero value,
Set CLASSC = to a non-zero value,
Set UNSOL = Y,
Set NUMEVE and AGEEVE
according to how often messages
are desired to be sent.
Quiescent The master never polls and
relies on unsolicited reports only. Set ECLASS to a non-zero value,
Set UNSOL = Y,
Set NUMEVE and AGEEVE
according to how often
messages are desired to be sent. Set CLASSA = to a non-zero value,
Set CLASSB = to a non-zero value,
Set CLASSC = to a non-zero value,
Set UNSOL = Y,
Set NUMEVE and AGEEVE
according to how often messages
are desired to be sent.