The DNP3 protocol can scale from very small, non-object oriented applications to large, complex object oriented assets. Though it may not be well known, DNP3 does have a data set feature that enables users to define object structures and to send them in events.

Furthermore, DNP3 has secure authentication features available on the market, TODAY. I am not aware of such features available right now for the transport layers of IEC 61850 (MMS).

I understand that the folk on the UCA committees are working on their own version of secure authentication. Readers may hear from many IT security "experts" who act as if authentication is trivial. However, very few who say such things have actually written standards with secure authentication. From personal experience as a reviewer, I can say that it is a lot of painstaking work; and getting it right involves many subtleties and details. Despite the punditry and hand waving, secure authentication is not a minor addition.

Basically, IEC 61850 is designed for infrastructure where bandwidth is not a primary consideration. The DNP3 protocol was designed for efficient, low bandwidth applications. Remember that not everyone can afford to run fiber everywhere. Sometimes links have to use expensive common carrier services or a low bandwidth radio link. Applications like those will continue to need an efficient transport protocol.

In any case, the DNP3 technical committee has been working on an effort to map various IEC 61850 objects to standard DNP3 address space. This transition will enable those users who might want to transition toward IEC 61850 some day to do so without requiring major forklift upgrades of intermediate equipment.

However, the primary point to be made here is that DNP3 and IEC 61850 are orthogonal tools for different applications. They are well suited for the purposes they were designed for. Neither is working at the expense of the other.

Jake Brodsky,

Chair DNP User Group