GE C30 Instruction Manual page 162

PRODUCT SETUP CHAPTER 5: SETTINGS
Figure 5-11: IEC 61850 TxGOOSE Access Points panel
TxGOOSE
IEC 61850 GOOSE is an efficient method for simultaneous high-speed delivery of a set of generic substation event
information in a publishing physical device to more than one subscribing physical device. A TxGOOSE is a UR element
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implementing a single IEC 61850 GOOSE message publishing service. The subscribing function in URs is performed by
RxGOOSE elements, as described in the next section. Each UR with IEC 61850 order code options has eight TxGOOSE
elements. Each TxGOOSE element can publish the values of up to 64 FlexLogic or FlexAnalog operands in the UR.
Published TxGOOSE messages configured in the EnerVista UR Setup software can be subscribed by and the published
operand values understood by other UR devices. In fact, they can be subscribed to and understood by any device of any
manufacturer that implements the IEC 61850 edition 1.0 or 2.0 GOOSE subscription mechanism. The messages are
published with a multicast address so that the network sends the messages to all devices; any number of devices that
want to subscribe can.
The entities whose values are published in GOOSE messages are known as members. The members are itemized in an
ordered list known as a data set. Each TxGOOSE can use any one of the data sets provided. See the DataSets section later
for details.
Each enabled TxGOOSE transmits its message whenever a value change is detected in one or more of its members. To
guard against the possibility that such a message is lost in the network before it reaches all subscribers, the message is
quickly retransmitted several times. To allow subscribers to verify that their link to the publisher and the publisher itself are
healthy, each message is also periodically retransmitted even while the values are unchanging. These latter messages are
known as heartbeat messages, while the former are known as event messages. Heartbeat messages also provide means
for a subscriber newly online to receive the published values in the absence of an event.
TxGOOSE1 and TxGOOSE2 scan for value changes in its FlexLogic operand members as frequently as such a change can
occur. TxGOOSE1 and TxGOOSE2 are therefore suitable for highly time critical signals, such as tripping and dynamic
blocking. FlexAnalog members are scanned for value changes only every 250 ms. See the Deadband Settings section later
for a description of what is considered a value change in an analog member.
The remaining TxGOOSE, meaning TxGOOSE3 and up, scan both their FlexLogic and FlexAnalog members for value
changes every 250 ms. They are suited for control applications, such as voltage control or power factor regulation.
The details of TxGOOSE message construction are contained in the UR Series Communications Guide. Knowledge of these
details is not required to configure GOOSE.
The UR does not implement the Fixed-Length encoded GOOSE messages option specified in IEC 61850-8-1:2011 clause
A.3; the UR always uses the ASN.1 Basic encoding rules (as specified in ISO/IEC 8825-1) as specified in IEC 61850-8-1:2004
and as optional in IEC 61850-8-1:2011 clause A.3. So do not try to configure the UR for fixed-offset TxGOOSE.
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