The first area that cellular comms started getting attention was for water supply and wastewater collection systems – as a backup to radio.

The requirements would state that radio was the primary communications and cellular GPRS was the backup on more important stations.

We also saw a few utilities who requested cellular as their primary communications method, either because they had had a lot of problems with radio in the past, or because their geography meant that building a radio network was clearly a lot more expensive than using cellular.

Let’s look at the thinking behind the backup first of all.

Historically, in water and wastewater, radio has the been the main method of RTU communications, with PSTN (phone lines) coming a long way behind in second place. One of the main benefits of radio was the fact that the utility owned the infrastructure and therefore “felt” some level of control over it.

In theory, if you own the infrastructure then you are able to run an operation which ensures an uptime that you are happy with, i.e., that meets the organizational requirements. If communications to one site goes down then you have a problem – but one that you can theoretically fix. If a repeater goes down, it’s the same situation.

Contrast that with cellular comms where if a cell tower goes down, or for some reason there are other comms problems in the backbone or to one area, you have to wait for the cellular operator to fix it.

But apart from those whose lifeblood is radio communications, this can also present a major disadvantage of radio communications. A lot of utilities don’t have the expertise to troubleshoot and fix radio systems, or to replace radio repeaters in the middle of a storm. Even if they do, there’s the question over response time. In later posts we will look at possible benefits of cellular, but for now, the radio “ownership” problem and the low cost of cellular comms raised the possibility of using cellular as a backup.

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.

• PID control, e.g. for constant pressure, constant flow via IsaGRAF
• New comms screen making all the communications much easier to setup
• Smart Outflow calculation to cater for high inflow conditions
• Updated DNP3 security (v2)
• Time to spill calculation on the main screen
• Generator functionality (e.g., run time and starts)

More about these features in later posts.

What else is in v2.1?

Fault finding tool – you can enable DNP3 and Modbus logging on the unit, then view the log on the LCD. We’ll do a post later which shows more about how this works in practice and why it’s useful.

Pump Running by External Control – the display shows when the over-ride is running the pumps (known via contactor auxiliary or currents). The main screen shows External Run next to that pump. And the starts and hours run accumulators also update. Thanks to Todd Burnett from Coastal Process & Steve Lahm from North East Water for requesting it (and maybe others as well).

DOUT from multiple sources – you can already do with this with IsaGRAF or the logic engine, but a few customers requested being able to configure a DOUT from a number of sources without using custom logic. So the user interface lets you choose a number of sources and select the “operator” – AND, OR, XOR.

Station Outflow alarm – there are already flow alarms by pump, this has been introduced to cover the complete station.

Cosmetic improvement - holding down a softkey repeats the keypress – greatly welcomed by anyone who has configured lots of faults and digital inputs for example.

Upgrading – the DSP upgrade is automatic, so you don’t have to remember to do that after a firmware upgrade. And when you put in a CF card with an upgrade image the unit prompts you to do an update.

Extra IO blocks in LCD – the Acromag and Adam IO units weren’t fully integrated into the LCD but now have been. Previously the available IO from external units didn’t show up in some of the settings screens (only in the advanced screens), but now do.

Custom names for IsaGRAF tags – the user can rename any IsaGRAF tag as well as change values, making the process a lot more intuitive.

Since v2 was released there have been a few minor releases. There are lots of small features and cosmetic improvements with a few more important additions. I highlight in bold the more interesting ones, but if you are a current MultiSmart user then any one of the smaller items may be important enough for you to want to upgrade.

If you do want to see every last “ticket” (as we call them), you need to get access to the MultiSmart firmware page, which you do by creating a login on the main site and requesting access to MultiSmart firmware. (Or, if you have already signed up, login and click “Edit my details”).

2.0.1 added

• Support for Single-Phase AC Monitoring and Fault Detection – important for smaller pump stations so that the “phase fail” functionality can be included
• Integrate Acromag IO Devices into screens
• Configurable units for pump efficiency
• Efficiency calculations during an overflow
• Show DSP Version number on Info page
• Invert Analog input value
• Telstra Modem support – CDR-882SEU & CDR-780SEU

 v2.0.2 added:

• Multiple thresholds on Insulation Resistance Test (IRT) -to allow a warning and a “fault pump” value
• Level device analog compare

v2.0.3 added

• Level locked feature – to indicate faulty level device
• I2T motor protection
• Protect reset accumulators via security login
• Support for redundant IP address

v2.0.4 added:

• Remote reconfiguration of DNP points list
• Display inversion – user selectable

A reminder that you can download the latest firmware for free from the MultiTrode website. We will shortly be releasing v2.1, so there will be a post about the main features in 2.1 very shortly.

Later, you have some memory of a useful website that you found but when you look in a likely folder under your bookmarks there are 50 links. Is it there? It’s hard to be interested enough to find it, so you do another Google search and start over..

I started experimenting with Diigo (www.diigo.com) a few days ago.

Diigo is one of many “social bookmarking” websites but seems to have some handy add ons.

What’s a social bookmarking website anyway? They are websites that let you share interesting websites with friends or colleagues.

What diigo offers which makes it more interesting – even if you aren’t interested in any sharing, is you can:

• highlight a section (or sections) of a webpage
• pin a post it note with your comments
• save it to your Diigo bookmarks with one or more tags

The tags concept lets you create your own categories and later search for the bookmarks under these categories.

It’s a simple solution to the problem that anyone who uses Windows Explorer to store files has found – you can only store a file in one location so later, you might try 5 different places to find what you are looking for. If instead you can tag up a website with a few different keywords you have much more chance of searching for it – and finding it – later.

Here’s an example below:

Commenting on and highlighting a section of a website

If you go to www.diigo.com and sign up you can add the diigo toolbar to IE (or Firefox). The toolbar lets you easily highlight and add your sticky notes or comments to a site – and to review all the websites you have bookmarked.

I’m on diigo as “stevecarson”. I’m going to try it out some more and see how it works for the sharing side..

Finally, there is always the chance that when the PO is with the supplier, he or she says “sorry, we’re out of stock of that model, but I have the next size up – tell you what, I’ll sell it to you for the same price as the smaller pump!”

The net result is pumps which are much too large for the application, running for very short times and not at all at their best efficiency point.

There’s a great article about how VFDs can improve the energy efficiency of pump stations by Joe Evans of Pentair writing for Pumps & Systems. The VFD lowers the effective output of the pump and runs it closer to its best efficiency point.

Another way that utilities solve the practical problem of the over-sized pumps is to add a jockey pump later on. This is a more appropriately sized pump for operation most of the time, with no concerns about worst case inflow condition because the larger pumps will take over.

Some stations are designed like this from the outset – especially stations with infrequent high inflow conditions where the engineer has recognized that large pumps are occasionally necessary but running these large pumps for very short periods is not ideal.

What’s the Lift Station Logic?

The lift station or pump station logic we use in MultiSmart is to group pumps.

So with the case of 2 large pumps and 1 jockey pump, Group 1 would have the jockey pump (let’s call it P1) and Group 2 would have both large pumps (let’s call them P2 and P3).

Group 2 would most likely be set to alternate – and it could be set to alternate based on efficiency to save energy automatically. Group 1 doesn’t need an alternation scheme because there is only 1 pump. (If there were 2 jockey pumps they would probably be set to alternate as well).

We configure the setpoints of P2 and P3 above the jockey pump, P1. And we set a parameter called Max Groups Running to 1, and Block Running Pumps to True (which is the default).

Now what happens is the level rises and P1 starts. The well empties and P1 stops. And the cycle continues. But once a time is reached when P1 can’t handle the inflow, the well level will keep rising and the start point for the lead pump in Group 2 is reached. When that happens, Group 1 (which just contains P1) turns off and the lead pump in Group 2 starts.

So long as this large pump empties the well, once the stop point for the lead pump is Group 2 is reached, Group 1 will again take over again from Group 2.

Depending on whether you have Duty/Assist or Duty/Standby you would set Max pumps to run in Group 2 accordingly. If you want both pumps to run together you don’t have to change the default (no limit), if you only want one pump to run, then you set Max pumps to run in Group 2 to 1. It’s an important point because a lot of stations don’t have the pipework to handle both pumps running together and all you do is double the energy consumed for a 10% increase in flow.

The way the logic works if Max pumps to run =1, and the level for the lag pump is reached, is the running pump stops and the other pump takes over.

Technical Note

The way the logic works by default, in high inflow conditions, the jockey pump, P1, will start each cycle, and then the larger pump will take over. If you don’t want P1 to always start, add some custom logic in IsaGRAF, or the logic engine. That logic would be very simple – once Group 2 starts, hold out Pump 1 (or Group 1), and then when the calculated inflow drops below a certain value, remove that hold out fault.

Summary of Configuration

Create a 3-pump station using the setup wizard
In Settings – > Alternation & Grouping:

• Create a new group
• Move P2 and P3 into Group 2
• Check Group 2 is in “Alternate (Std)” – the default
• Check that Group Alternation is “Fixed (Std)” – the default

Configure your setpoints as you want through Settings -> Setpoints -> Level/Control Setpoints
If you do want only one of the large pumps to run at one time, configure Max Pumps to Run in Group 2 – Settings -> Advanced – > Pump Control -> Group -> Group 2 -> Max pump running

Compared with a protocol like Modbus, DNP3 has way more features. That’s another way of saying that it is a lot more complex.

Modbus compliance is very easy to test. Suppose you have an RTU with Modbus Slave – a unit which will be polled by a master PLC or RTU. To test it, you can download any one of a number of free or demo Modbus tools and check that you can read a set of registers and write to a set of registers. That’s not the complete functionality of Modbus but it does confirm that the basic functionality works – and because the protocol is so simple, the product vendor is unlikely to have got it wrong. One tool readily available is the Kepware OPC server and you can download a demo version from their website.

As the end-user or system integrator implementing DNP3, if you have to put together a master from one supplier and a slave from another, when it doesn’t work who do you call? Or if you are taking advantage of the fact that DNP3 is an open protocol supported by many vendors you might be choosing a number of different field products – each one suited best for the application at hand.

DNP3 has the flexibility you need for reliable, secure telemetry but there’s a lot of features to test.

The smartest approach is to get the vendor to do it for you before you start using the product or software. If you ask for an independent certification you know that the protocol has been tested by someone who’s reputation is on the line if they miss something.

To get an idea of what gets tested in DNP3 certification you can see a copy of a full test report on the MultiSmart RTU on our main site, under the product manuals section of MultiSmart – www.multitrode.com/pump-station-manager/product-manuals.html

Some people might be interested in the latest MultiSmart brochure now on the main website.

You can find it under the MultiSmart section of the website, at www.multitrode.com/pump-station-manager/data-sheets.html

Some people prefer to read a “real paper” version, so you can always ask your local MultiTrode sales office to give you a copy.

We like to encourage less paper but the reason we printed a few thousand is that we know it’s not an easy shift to have everything as a soft copy and not print it out.

Multismart-brochure

Part One: Date/Time Stamping – or Less Guessing
Part Two: Communications Options – Polling and Unsolicited Reporting
Part Three: Security

The DNP3 protocol also supports guaranteed delivery. What does this mean?

Suppose you want to send a command to start a pump. How do you know the RTU at site received the command? With some older and simpler protocols the only way to check is to read the status of the pump at a slightly later time – and hope you catch it in the act.

Or suppose you want to ensure that the message High level alarm or All pumps unavailable sent from the RTU was not missed by the master station or SCADA? With some protocols, like Modbus, there isn’t any mechanism for ensuring this.

DNP3 provides message acknowledgements. With unsolicited reporting, the RTU might send all changed data every half hour, or if the event buffer was full. The “message” that the DNP3 protocol sends includes all the tags that have changed with the date/time of each, and also includes a sequence number. The master station would send an acknowledgement to the RTU – or “outstation” – that that sequence number had been received.

In the event that the RTU / outstation didn’t get that confirmation, it would retry. And after a certain time period the site would go into a Comms Fail mode with probably a longer retry delay. I say “probably” because that depends on how the user sets it up, but that would be the sensible approach.

As you can see if you’ve been following this series on DNP3, the creators of DNP3 designed it for the challenging world of telemetry where communications is always suspect and often problematic.

There’s more to configure in the protocol of course, but each element is there to ensure data integrity:

• you know what happened
• exactly when it happened
• you can guarantee that the SCADA system knows about it
• and you can ensure that data is genuine and not from a hacker

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..