News:

  • March 28, 2024, 05:00:34 AM

Login with username, password and session length

Author Topic: DNP3  (Read 7895 times)

henke

  • Full Member
  • ***
  • Posts: 21
Re: DNP3
« Reply #15 on: January 31, 2018, 10:47:28 PM »
A plain language description of the DNP3 Protocol for anyone who is a data comm geek or just curious... https://www.dnp.org/AboutUs/DNP3%20Primer%20Rev%20A.pdf
Where's my kitty?

BobO

  • Host Moderator
  • Hero Member
  • *****
  • Posts: 5975
  • Yes Pinky, Do-more will control the world!
Re: DNP3
« Reply #16 on: February 01, 2018, 10:54:53 AM »
For DNP3, would you just do Ethernet, or should we consider other physical layers like RS485? Just wanting to support what is in common use, not trying to be all things to all people.
"It has recently come to our attention that users spend 95% of their time using 5% of the available features. That might be relevant." -BobO

Controls Guy

  • Internal Dev
  • Hero Member
  • ****
  • Posts: 3553
  • Darth Ladder
Re: DNP3
« Reply #17 on: February 01, 2018, 12:00:24 PM »
Interesting that the group behind the WITS DNP3 variant has decided to try to broaden their appeal by a renaming to “Worldwide Industrial Telemetry Standard”.
  http://www.witsprotocol.org/2018/01/

I hope it's better than the old WITS, that was kind of a pain in the butt.
I retract my earlier statement that half of all politicians are crooks.  Half of all politicians are NOT crooks.  There.

henke

  • Full Member
  • ***
  • Posts: 21
Re: DNP3
« Reply #18 on: February 04, 2018, 03:20:45 PM »
For DNP3, would you just do Ethernet, or should we consider other physical layers like RS485? Just wanting to support what is in common use, not trying to be all things to all people.

Certainly the Ethernet flavor would be the top choice! I recently watched a visiting engineer set up a connection to an existing SCADAPack(non-E) using VTSCADA and he made it look trivial. It's a bit more complicated using ClearSCADA but here's a nice writeup on that procedure. https://du5tin.com/2017/06/18/setup-clearscada-ethernet-dnp3-communications-to-a-scadapack-non-e-series/

Many devices nowadays are trending toward direct network connectivity but of course there will be a considerable contingent of legacy serial remaining out there ... change in some parts of industry happens at a glacial pace. There are simple enough ways to address this for example using an Ethernet<->Serial conversion device such as a Digi One SP.
« Last Edit: February 04, 2018, 10:16:52 PM by henke »
Where's my kitty?

AustinT

  • Full Member
  • ***
  • Posts: 35
Re: DNP3
« Reply #19 on: February 06, 2018, 05:57:14 AM »
I hope we see both Ethernet and serial dnp on the Brx.  I run/develop the scada for a power utility and in many remote locations we have serial radios operating in the 450 band . On these radios we have both reclosers with the ability to talk modbus/ dnp and plc’s with only modbus.  We are forced to hold all of the devices on the radio loop at modbus because of the lack of dnp support from plc’s. 

henke

  • Full Member
  • ***
  • Posts: 21
Re: DNP3
« Reply #20 on: February 06, 2018, 11:54:14 PM »
The system that Austin highlights is typical of many power utilities operating at 9600 or even 1200 bps. The ethernet converter I commented about would only talk to the head radio which kinda negates the benefits of ethernet. My "terms of reference" is a municipality with a robust ethernet 900mhz ISM radio network dating from 2005 onward. The beauty of DNP3 via Ethernet is that when links drop on occasion, as soon as they restore the built-in DNP3 buffer is polled and fills in the gap in data. I imagine the same would apply via serial radio. So yeah, seems there's a strong case for serial as well.
Where's my kitty?

henke

  • Full Member
  • ***
  • Posts: 21
Re: DNP3
« Reply #21 on: March 28, 2019, 01:18:52 PM »
Bump.

There's no doubt that DNP3 is a very complex protocol to implement and integrate. Toto, I've a feeling we're not in Kansas anymore...

The view of it from a user perspective would be a data grid or lookup table where:
- the deadband for each analog value is defined so that only a distinct change-in-value is logged and eventually polled.
- the debounce time for each boolean value is defined so that only a distinct change-in-value is logged and eventually polled.
- each point is assigned a "event class" of 1, 2, or 3, to allow three different reporting priorities.

https://en.wikipedia.org/wiki/DNP3#Technical_details
Where's my kitty?

BobO

  • Host Moderator
  • Hero Member
  • *****
  • Posts: 5975
  • Yes Pinky, Do-more will control the world!
Re: DNP3
« Reply #22 on: March 28, 2019, 01:20:13 PM »
Bump.

There's no doubt that DNP3 is a very complex protocol to implement and integrate. Toto, I've a feeling we're not in Kansas anymore...

The view of it from a user perspective would be a data grid or lookup table where:
- the deadband for each analog value is defined so that only a distinct change-in-value is logged and eventually polled.
- the debounce time for each boolean value is defined so that only a distinct change-in-value is logged and eventually polled.
- each point is assigned a "event class" of 1, 2, or 3, to allow three different reporting priorities.

https://en.wikipedia.org/wiki/DNP3#Technical_details

We love the idea. There's just too much on our plate at the moment.
"It has recently come to our attention that users spend 95% of their time using 5% of the available features. That might be relevant." -BobO

BobO

  • Host Moderator
  • Hero Member
  • *****
  • Posts: 5975
  • Yes Pinky, Do-more will control the world!
Re: DNP3
« Reply #23 on: March 11, 2020, 03:14:01 PM »
Probably best not to be advertising products of our competitors here.
"It has recently come to our attention that users spend 95% of their time using 5% of the available features. That might be relevant." -BobO

henke

  • Full Member
  • ***
  • Posts: 21
Re: DNP3
« Reply #24 on: March 13, 2020, 12:45:13 PM »
Understood.  :-X  I'll PM the mod rather than post.
Where's my kitty?