Novatech Bitronics M87X Series Manual page 166

Example 3. Ethernet, using GSSE:
The GSSE service, as defined by IEC-61850, is identical to what has been called GOOSE
in connection with UCA2.0 in past years. In order to reduce confusion as far as possible,
all previous references to GOOSE in the UCA context have been replaced by the
expression GSSE in 70 Series documentation because IEC-61850 supersedes UCA as a
communications standard.
The use of GSSE to perform cross-triggering carries all the practical advantages of
GOOSE and is simpler to set up, but has much narrower multi-vendor support. It is,
however, available on all 70 Series IED firmware versions released since April 2004, so
GSSE may be a better choice when it is either unnecessary to trigger other devices, or
when triggering other vendors' devices might as easily be accomplished with discrete
digital I/O while using GSSE among the 70 Series IEDs installed.
As with GOOSE, there is no need to make use of any other aspect of 61850 or UCA
protocols just to use GSSE for cross-triggering.
GSSE can generally be envisioned as a way to communicate a binary status over an
Ethernet medium, exactly analogous to status and control performed by discrete I/O points
(see Example 1). GSSE messages are reliable enough to be used for controlling
interlocks and protective relay blocking schemes, and can be propagated even faster than
discrete digital contacts because of the time that it takes for moving mechanical parts to
operate.
GSSE operates by means of transmitting and receiving unsolicited, unacknowledged,
multicast messages on an Ethernet LAN, so GSSE messages can not pass through a
router into another network. In its simplest form, such a network could consist of as little
as an Ethernet switch and the inter-triggered IEDs connected via conventional Cat. 5
cables. There is no need to uplink into any wider LAN or to operate with any other clients
or servers on the network (except for the purpose of configuring the IEDs). So in a
substation, security could be accomplished easily just by restricting physical access to the
network.
Otherwise, when used in a secure general purpose network, GSSE messaging can coexist
unobtrusively with other network traffic including file transfer services useful for collecting
the recordings captured by the IEDs.
Connection:
The M87x must be fitted with one of the available Ethernet options and be connected to a
Local Area Network (LAN). There is no other minimum hardware requirement for an M87x
to support GSSE. Older units that support UCA but not 61850 can exchange cross-
triggers via GSSE from newer units that support 61850.
Configuration:
All settings required for cross-triggering with GSSE are made in the 70 Series
Configurator. The following steps illustrate a typical configuration:
1. In the 70 Series Configurator, Figure A13 shows how any event of interest measured
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ML0021 August 15, 2018 Copyright 2018 Bitronics, LLC