17.5
Date Code 20171006 Instruction Manual SEL-400 Series Relays
IEC 61850 Communication
IEC 61850 Operation
MMS
Manufacturing messaging specification (MMS) provides services for the applica-
tion-layer transfer of real-time data within a substation LAN. MMS was devel-
oped as a network independent data exchange protocol for industrial networks in
the 1980s and standardized as ISO 9506.
In theory, you can map IEC 61850 to any protocol. However, it can become
unwieldy and quite complicated to map objects and services to a protocol that
only provides access to simple data points via registers or index numbers. MMS
supports complex named objects and flexible services that enable mapping to
IEC 61850 in a straightforward manner. This was why the UCA users group used
MMS for UCA from the start, and why the IEC chose to keep it for IEC 61850.
MMS associations are discussed within IEC61850-8-1, clause 10 of the edition 1
standard.
If MMS authentication is enabled, the device will authenticate each MMS associ-
ation by requiring the client to provide the password authentication parameter
with a value that is equal to the 2AC password of the relay.
➤ If the correct password authentication parameter value is not
received, the device will return a not authenticated error code.
➤ If the correct password authentication parameter value is received,
the device will provide a successful association response. The device
will allow access to all supported MMS services for that association.
Control
IEC 61850 Controls
An IEC 61850 server may allow a client to manipulate data related to its outputs,
external devices, or internal functions. This is accomplished by the IEC 61850
control model, which provides services to execute control commands. The con-
trol models are defined in IEC 61850-7-2 and the mapping to the MMS (Manu-
facturing Message Specification) application protocol is defined in IEC 61850-8-1.
The former describes control functionality while the latter maps the IEC 61850
control primitives to MMS.
SEL-400 series relays support four different control models:
➤ Status Only
➤ Direct with Normal Security
➤ Direct with Enhanced Security
➤ SBO with Enhanced Security
SEL-400 series devices support the above control models for SPC and DPC con-
trollable common data classes (CDCs) as defined in IEC 61850-8-1:2004. Other
controllable CDCs defined in the standard are either unsupported or must be con-
figured with the status-only control model. Supported CDCs include remote bits
RBGGIOn in the CON Logical Device (LD), and breaker and disconnect switch
controls xxXCBRnn and xxXSWInn in the PRO LD. One control model must be
selected during initial IED configuration in Architect and is applied throughout
the CID file. This control model will apply to all controls in the IED.
To Next Page
Loading...
