MOXA’s Dual Protocol Approach: MMS and SNMP

MOXA has announced to support a dual protocol approach in their communication infrastructure: IEC 61850/MMS and SNMP.

This is no surprise: already in the first year of standardization of IEC61850 EdF (France) proposed to use SNMP (simple network management protocol) to carry IEC 61850 payload modeled in a specialized MIB. There was very little support for SNMP.

It is natural that the communication infrastructure also provides IEC 61850/MMS access to the many data objects used in switches, routers and other equipment. IEC 61850-7-4 Edition 2 has a lot of new – communication related – logical nodes that are linked directly to network management like “Physical communication channel supervision” logical node (LCCH):

RxCnt - Number of received messages
RedRxCnt - Number of received messages on redundant channel
TxCnt - Number of sent messages

This is related to the communication infrastructure … Or?

Click HERE for details from MOXA.

MOXA concludes in a White paper:

“Moxa’s new line of PowerTrans IEC 61850 switches now come with full MMS compatibility, with a complete implementation of IEC 61850 data modeling and a built-in MMS server. Our entire line of substation computers, switches, and other associated hardware all still feature our own enhanced SNMP support (with custom MIB files), but Moxa welcomes any inquiry into further customizing our switches, embedded computers, and other substation IT hardware with full or enhanced MMS support, made to your order.”

IETF Energy Management WG (EMAN) inspired by IEC 61850 and CIM

IETF EMAN, Energy Management, is an active WG that is modeling (in the MIB) a lot of power related real world objects “connected” one way or the other to a network.  SNMP is used to access this information. The objective of Energy Management (EMAN) is to provide an energy management framework for networked devices.

Networked devices could be Ethernet switches, routers, battery controller, other storages,  gateways, … more or less anything that is connected to a network!

http://tools.ietf.org/wg/eman/

The WG sees IEC 61850 as the most applicable standard to EMAN. Concepts from IEC 61850 and CIM have been reused (somehow) by the EMAN WG. A closer cooperation of the models would be appreciated by the next generation of engineers and programmers …

There is ONE real world – many models could be thought of to describe that single real world. I hope that for energy applications we will prevent to get too many models. IEC 61850 models should be used as default solution in all devices closely connected to the physical level of energy systems … different notations and protocols may be used BUT the content/semantic should be identical!

A MMXU should model the 3-phase electrical system – all over and in all models.

Interoperability for Intelligent Devices for Transportation

A very comprehensive set of standards for information models and information exchange has been published for ITS (Intelligent Transportation Systems; defined and used in the U.S.). One crucial objective is to reach Interoperability: "A standards-based approach to integration helps to facilitate the exchange of transportation data as well as more easily accommodate future equipment replacements, systems upgrades, and system expansions."

The standard NTCIP 1213, for example, defines a couple of information models that are also defined in IEC 61850.

NTCIP 1213 v02.19 (National Transportation Communications for ITS Protocol -- Object Definitions for Electrical and Lighting Management
Systems (ELMS))

Examples of three phase voltages for Delta and Y, current and power:

BranchcircuitEntry::= SEQUENCE {
...
branchcircuitVoltageAB INTEGER,
branchcircuitVoltageBC INTEGER,
branchcircuitVoltageCA INTEGER,
branchcircuitVoltageAN INTEGER,
branchcircuitVoltageBN INTEGER,
branchcircuitVoltageCN INTEGER,
branchcircuitCurrent   INTEGER,
branchcircuitPower     INTEGER
...
}

These models are mapped to MIB (SNMP) and communicated, e.g., in ASN.1 BER - as is the case for IEC 61850-8-1. It would be nice to use the IEC 61850-7-4 MMXU (three phase electrical measurements for all applications - independent of transportation, distribution, generation, ...).

Smart Power Distribution Grids will have a lot of relations to Transportation Systems and vice versa.
No Power System - NO Transportation!

The NIST Smart Grid activities list the NTCIP part 1213 in the SGIP Identified Standards (number 31).

Click HERE for the ITS website ... provides free access to model and protocol standards, e.g. part 1213 can be accessed for free (registration required).
Click HERE for more information on the ITS Standards Background.

Draft IEC 62351-7 - Network and System Management objects

The IEC TC 57 Committee Draft for IEC 62351-7 TS Ed.1 has been published the other day (document 57/1003/DTS):
Power systems management and associated information exchange – Data and communication security – Part 7: Network and system management (NSM) data object models

Closing date for comments: 2009-08-07
(contact your national TC 57 committee for a copy).

These NSM data objects will be used to monitor the health of networks and systems, to detect possible security intrusions, and to manage the performance and reliability of the information infrastructure in power systems.

Scope and Objectives

Power systems operations are increasingly reliant on information infrastructures, including communication networks, intelligent electronic devices (IEDs), ... Therefore, management of the information infrastructure has become crucial to providing the necessary high levels of security and reliability in power system operations. Using the concepts developed in the IETF Simple Network Management Protocol (SNMP) standards for network management, IEC 62351-7 defines Network and System Management (NSM) data object models that are specific to power system operations. These NSM data objects will be used to monitor the health of networks and systems, to detect possible security intrusions, and to manage the performance and reliability of the information infrastructure. These data objects are defined as abstract data objects. These abstract data objects will be mapped to specific standards, such as IEC 61850, IEC 60870-5, IEC 60870-6, IEC 61968/61970 (CIM), web services, SNMP. These mappings will be defined later.

The utility industry should take these activities very serious - the many objects that will be standardized have a crucial impact on the power system monitoring! It is likely that the infrastructure will provide much more status information (provided by many "software" sensors) than the power delivery process (breaker status, voltage, current, oil pressure of a transformer, ...). Be aware that the ICT (information and communication technology) infrastructure will become very comprehensive (!!); may no too complex - but providing hundreds or thousands of new "Signals" not needed today! Get involved in the future of YOUR power system.