A protocol defines the rules by which devices talk to each other. DNP3 is a protocol for transmitting data from Point A to Point B via serial and IP communications. Although DNP is most commonly used by electric, gas, water and wastewater utilities, it can be used anywhere a SCADA system is exists.

Why Do Devices Need to Talk to Each Other?
Utility providers commonly have lots of operations they need to monitor. Typically, there is a central operations center plus remote equipment in the field.  The central operations center houses their main computer.  Installations/substations house remote equipment in the field.  DNP is used to facilitate communication between the main computer and remote equipment, enabling the main computer to remotely open/close circuit breakers, measure line voltages, start/stop motors, open/close valves, check for errors, etc.

View Previous Blog Series on DNP3:

DNP3 Part 1 – Date/Time Stamping

DNP3 Part 2 – Communications Options

DNP3 Part 3 – Security

DNP3 Part 4 – Reliability

DNP3 Part 5 – Compliance

The firmware can be downloaded if you have been given access to the firmware area. Create a login on the main site and request MultiSmart firmware (one of the checkboxes). If you already have a login, click on “Edit my details” in the top right of the main site.

v2.0 of Multismart was released in July 2008 and came with some major enhancements.

PLC functionality

IsaGRAF v5 was added in as an option to the product. This means that a full IEC61131-3 compliant PLC extension is available (all 5 languages).

How does it integrate and when is it needed?

First thing to mention is that the code behind MultiSmart is NOT written in a PLC language. It’s in C++ for a whole bunch of reasons that I hope to get our software team to elaborate on at a slightly later date.

What MultiSmart does do is make ALL of the many tags (1000’s) available to the PLC module for reading and writing. This then allows a PLC programmer to extend, change or add totally new modules, without having to rewrite the complete application or module from scratch.

Praveen wrote a post recently about a customer who wanted to match dosing of SulfaLock to the flow rate for odor control. It’s such a custom requirement that you wouldn’t expect to find it in the standard list of MultiSmart functions! So Praveen developed it for the customer in IsaGRAF. The customer or his SI could have done the same, so it’s not dependant on MultiTrode engineering staff writing the application. Of course, we like doing custom applications because it’s a great opportunity to learn more.

Another PLC application would be testing a high level alarm in a specific way – turning the pumps off periodically, letting the level rise, and ensuring the high level alarm actually operated. That’s a function that we might include as standard at some stage, but I’m sure you get the idea.

How might that work?  The PLC application would interface to the pump controller module - maybe based on date/time and certain other conditions being met (low flow rates, no pump alarms last 3 days), and turn the pumps off, then monitor the level to where the high level alarm should activate. If it does activate, start the pumps, send a “High level alarm check ok” signal to SCADA and reset the high level alarm. If it doesn’t activate, still start the pumps (!), send a “High level alarm FAIL” signal to SCADA and reset the high level alarm.

There is a lot of functionality in MultiSmart so a challenge for us is educating our customer base as to what’s there so someone doesn’t spend a week or two rewriting something we have already done and tested..

Another enhancement in v2 is to be able to view all tags on the LCD screen, including IsaGRAF tags and the entire tag database (go to the Info screen on MultiSmart) – makes on-site troubleshooting a lot easier!

DNP3 Security

The new standard for DNP3 security was out so we included it in MultiSmart v2. There’s a big concern about security in SCADA communications so we moved it to the top of our queue. You can find out more in this DNP3 Security post.

More Expandable I/O

We added some off the shelf I/O blocks and integrated them into the user interface. Why 3rd party I/O modules? Standard I/O is pretty much a commodity these days so there are plenty of great modules out there. We added two Adam units from Advantech, and in 2.01 added two UL-listed Acromag units. They connect on Ethernet using Modbus TCP protocol.

What we’ve done in MultiSmart I/O is focus on specific pump station requirements, so even though the most common I/O card you find in MultiSmart has 2x 4-20mA Analog inputs, 1x 4-20mA Analog output, 7 Digital outputs and 20 Digital inputs – there are some extras. The Digital inputs as default are volt-free contact closure inputs but can also be configured to read Flygt FLS, PTC thermistors, seal sensors, conductive probe inputs (for the MultiTrode probe), and a few can be configured to be Flygt CLS or high speed counters. The card also includes 3 inputs for reading phase-to-phase supply directly – up to 600v input.

And the energy and pump efficiency card reads 3-phase currents, and provides insulation resistance. Reading all this I/O usually means you have to buy lots of parts to do the signal conditioning. So most people don’t do it and spend lots of time driving to site to see what’s going on..

All of these pump station specific I/O makes the control panel, simpler, more intelligent, smaller – and of course lower cost.

But when it came to another card for 8x standard AINs or 16x standard Digital Inputs we thought why not just a card from someone else?

Import and export of DNP3 and Modbus tags

You can now export the DNP3 and Modbus tags as a .csv file and save it onto the CF card – or read it via ftp. And you can re-import the tag list back after modifying it.

This matters because as a default there are 400-500 tags in MultiSmart and if you want to play around with that configuration it takes a while through the user interface. Also you might want to synchronize data with a SCADA configuration file or master PLC.

Energy Monitoring and Energy Saving

v2 includes “Run the most efficient pump”, also known as “Alternation by efficiency”

This allows automatic saving of energy. You set a parameter for the ratio to run – e.g. run the most efficient pump 20:1 compared with the other pump(s). If it just ran the most efficient pump, the system could never get an opportunity to recheck – or to check the other pump runs ok.

How much do pumps drop in efficiency? I.e. how much can you save? It’s one of those values that people rarely know. As one major pump supplier said to us, “We all know the pump curve the day it leave the factory, but 1 year, 3 years later, what is it like? No one knows” They showed us a study they had done but it’s confidential. We did put some studies that we found on the Energy & Environment page on our main site, which indicated that wastewater pumps were often more than 15% below their original efficiency. Even clean water pumps can degrade significantly – always a surprise.

So the Run most efficient pump feature gives a change to automatically and easily save energy costs.

Other features

There’s a couple of other minor features:

• Digital Output pulse and delay functionality
• Support for relative level

How do I get v2?

Easy. I’m assuming you have a MultiSmart of course. If you don’t, and you have a lift station, try one out!

If you do, you can download the firmware for FREE from the multitrode.com website. You can find the link under the Training and Support section at http://www.multitrode.com/firmware-upgrades.php

You will need to signup on the site. If you don’t already have a login, just click the Signup button in the top right (of the main website), and check the box – Please give me access to the free MultiSmart firmware upgrades & release information. If you do already have a login and haven’t been in the MultiSmart firmware access section before, make sure you are logged in and click the Edit my account details link, then check the MultiSmart firmware access box.

We process that request manually so it usually takes a day, sometimes less - but if you are in a hurry you can always call up your MultiTrode office and speed things up.

How do I find out about New Versions?

Easy. Follow this blog. If you haven’t already subscribed just click the Subscribe by RSS    or Subscribe by Email icon in the top right. Find out about Subscribe by RSS.

Alternatively, or as well, to make sure you don’t miss anything, in the instructions above (”How do I get v2?”) about editing your login details to the MultiTrode site, you can check the box Please update me on email with all new releases of software or hardware in the MultiTrode family of products (MultiSmart/PumpView/Outpost2).

If you are a MultiSmart customer it’s well worth finding out the details of all the new features. It’s free to upgrade!

More about some minor MultiSmart updates since v2 in a later post..