DLMS Summary

Revision A - 22 MARCH 1996

	Name	Position	E-mail address
Author(s):	Mats Grahm	Technical Coordinator	pt93mg@pt.hk-r.se
Responsible:	Martin Puhv	SAGA Team Manager	pt93mp@pt.hk-r.se
To:	SAIDA		saida@pt.hk-r.se
Cc:

Abstract

This document describes briefly what DMLS is, and what relevance it has to the SAIDA project.

1 What is DLMS?

DLMS stands for "Distributed Line Message Specification" and can best be described as a Client/Server protocol that has been designed specifically for controlling equipment over power lines. DLMS is, strictly speaking, just the topmost layer (application layer in OSI terminology), and could therefore be used on any media.

It is hard to figure out much from the very sparse documentation that is available. But it appears that DLMS is more than just a protocol, it defines a sort of framework where "virtual equipment", "virtual datasets", "virtual variables", and "virtual associations for applications" are defined. For those objects an interface is specified, but the actual implementation is left to the manufacturer o f the real devices.

2 Comparing DLMS with LCA

In many ways DLMS addresses the same problems as LCA/LNS does. It tries to set a standard that will allow future hardware and software from different developers to work together.

It is not clear if DLMS and LNS are mutual exclusive, or if it would be possible to use them together. But it is hard to see how DLMS could be to any help in project SAIDA. The DLMS framework looks very different from LCA/LNS, and mixing the two seems to be a bad idea. To base the communication on DLMS seems to require either to totally abandon Echelon technology, or to encapsulate the entire LNS network in a DLMS wrapper. Since we don't have any existing client software built on DLMS, such an effort would be meaningless. And nowhere in the paper is any tools or applications mentioned that could be used with DLMS. It would take substantial research to even get a good idea what DLMS really is, and how it could be used.

3 Conclusions

It seems like using DLMS would create huge difficulties, while not solving any problems at all.

DLMS Summary
Abstract
1 - What is DLMS?
2 - Comparing DLMS with LCA
3 - Conclusions