Abstract Communication Service Interface (Asci) - GE UR Series Manual

CHAPTER 3: IEC 61850 COMMUNICATION
• Read/write services — These services allow a client IED to obtain a directory of a server's signals and to read and write
the server's signal values one at a time, or a few related values at a time. These services are implemented on a stack
consisting of MMS, TCP, IP, and Ethernet protocols. UR series devices participate in these services as server IEDs, not as
clients.
• Command services — These services allow a client IED to send commands to a server IED, to for instance open and
close circuit breakers through a server IED, and to confirm that the command was successfully executed. These
services are expected to be completed in the order of half a second. Again these services are implemented on a MMS,
TCP, IP, and Ethernet stack, and UR series devices participate as servers, not as clients.
• Report services — These services allow a client IED to set up a server IED to send the client messages containing the
values of a set of predefined signals periodically, on request, and/or whenever one of the signals undergoes a change
of state or value. The reports are expected to be completed in the order of one second after a signal change of state.
Again these services are implemented on a MMS, TCP, IP, and Ethernet stack, and UR series devices participate as
servers, not as clients.
• GOOSE — This service allows a publisher IED to transfer a predefined set of signal values to one or more subscriber
IEDs periodically and/or whenever one of the signals undergoes a change of state or value. This service is intended for
trip and blocking signals, and is expected to be completed in the order of three milliseconds for some message types.
This service is implemented directly on the Ethernet protocol. UR series devices implement the publisher side of this
service under the name TxGOOSE and the subscriber side of this service under the name RxGOOSE.
• Sampled values (SV) — This service allows a publisher IED to transfer a predefined set of values of its signals to one or
more subscriber IEDs periodically. This service is intended for analog signals whose waveform needs to be
reconstructed by the subscriber, such as power system voltage and current signals, and synchrophasor signals.
Sample rates for different applications can range from thousands to once per power system cycle. This service is
implemented directly on the Ethernet protocol. UR series devices implement the publisher side of this service for
synchrophasors.

3.1.2 Abstract Communication Service Interface (ASCI)

The Abstract Communications Service Interface (ACSI) is defined in IEC 61850 7-2, 61850 7-3, and 61850 7-4. A
fundamental component of ACSI is its information model, which defines the ACSI names of signals, and attaches a
"semantic" to name parts. A semantic is a usually brief description of what the named item represents. For instance, the
name part "stVal" has the defined semantic "Status value of the data".
The figure shows the information model that organizes the native device signals.
UR SERIES – COMMUNICATIONS GUIDE
OVERVIEW
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