Category Archives: Automation

As Technology Buffs, We’re Blinded to the Obvious Uses of Technology

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Are you old enough to remember the early 90’s? Almost nobody was “online” then. It’s hard to believe how much the internet has changed modern life since then. I just went through my bookshelf and got rid of all the reference books (which I could have done years ago) because the internet makes them obsolete.

Do you remember having to look up some arcane technical detail in a book? Do you remember how painful that was? Do you remember connecting to a BBS using a phone line and a 2400 baud modem? I do.

Back then when we tried to imagine the future, we (as geeks) really got it wrong, and surprisingly so. We were the ones who were supposed to see the possibilities, yet we consistently imagined the things we wanted to do with the technology instead of the things the average person wants to do with it. You see, geeks aren’t average people, so we’re sometimes blind to the obvious.

As geeks, we imagined having our own robot to do our bidding, or some kind of virtual reality headset for driving cars around on Mars. In reality, the killer app for the masses was the ability to take a picture of something, write a short note about it, and send it to all your “friends”. The funny thing is, if you asked a geek in the early 90’s if that feature could be the basis of a company valued in the billions of dollars, they’d have laughed you out of the room. The idea just wasn’t that revolutionary. After all, we’d had fax machines for several years, and email/usenet were already out there. Geeks already had access to this technology, and thought nothing of it.

Average people, if they even saw this technology, didn’t see what was under their noses either, simply because it wasn’t sexy yet. Let me be clear, when I say “sexy” I mean it literally. The average young person isn’t like a geek. They don’t have robots and virtual reality sets on their mind, they want to know who’s going to be at the party on Saturday, who said what about who, and if so and so is available. Modern social media succeeds because it helps people satisfy the most basic of “normal” wants.

Where am I going with this? When you look at the bleeding edge of technological progress today it’s easy to spot the trends. Open source hardware has really taken off, specifically 3D printing and other “home” fabrication technologies. We’re also seeing an explosion of sensors, not just in your phone, but also plugged into consumer devices, with most of them uploading their data to central servers (e.g. the popular Nest Home Thermostat).

We all want to know what the next big thing will be, and we’re hopelessly bad at predicting it, but we still like to play the game. If we want to know where this new hardware renaissance is leading, we need to look at the space where these new technologies intersect the wants of average people. Only about 1% of users are the kind that participate by actually creating new content, so I definitely don’t see a future where everyone is designing new things in Google Sketchup and printing them out on their 3D printer they bought at Wal-mart. The thing about 3D printers is that they print things we can buy much more cheaply (little plastic trinkets), especially if it’s the type of thing that a lot of people want, so there’s an economy of scale to support manufacturing it.

There is something that everybody wants to create at home, and can’t be mass produced in a factory on the other side of the world: freshly prepared food. Gourmet food, even. People pay big bucks for fancy coffee makers that make fancy coffee from packets with barcodes containing individualized brewing instructions. It’s not a big stretch to imagine a machine that can whip up fancy cocktails, or dozens of fancy hors d’oeuvres for a party, or even print out your kids’ drawings on their Christmas cookies with icing from a 3D printer. Maybe a gizmo that carves an apple into the shape of their favorite cartoon character? (Of course, you know these will be re-purposed to make snacks for bachelorette parties, right?)

That’s the easy stuff. Honestly, Eggs Benedict seems like it’s well within the range of possibilities, and who wouldn’t want to wake up on Sunday to the sizzle of eggs and bacon, along with the usual coffee brewing?

Of course, if we automate the food preparation and we’re collecting all this data with sensors, it won’t be long until we’re automating the control of our caloric intake.

That’s my guess anyway: all this new technology’s going to end up in your kitchen. Which is cool with me (that doesn’t mean I can’t still have my 3D printer…)

Finding Inexpensive 24VDC Power Supplies

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I happen to have been in the market for some switching 24VDC power supplies that could source some decent current and put up with a little abuse. It turns out there’s no need to spend hundreds of dollars for one of the fancy DIN-rail mounted models when all you need is a box to sit on your test bench.

You can order them directly from Chinese suppliers, but it’s more convenient to order from someone domestic. I’ve found a good place to look is Amazon (a close second is E-Bay, but you’re really buying from China in about 50% of cases there). On Amazon you can get a 15A 24VDC power supply for well under $30:



Obviously this is a “buyer beware” type of situation, but I’ve purchased 3 similar power supplies so far, and haven’t had any problems. In one case the equipment under test shorted out due to a blown capacitor, and the power supply turned itself off until I cycled the power to the supply. It’s still working fine.

You may think that a $300 brand name power supply is what you need, but if you don’t need five 9’s of reliability then I’d like to point out you can buy ten of these cheap supplies for the same price, so buy 3 and keep 2 on the shelf, and spend the other $210 on other cool gadgets! 🙂

More Control Systems Found Attached to the Internet

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Back in November I published a blog post about Finding Internet-Connected Industrial Automation Devices and one of the scariest things I found was a wind turbine in Oklahoma with no apparent authentication.

Recently Dan Tentler took this several steps further and posted his video from the LayerOne 2012 security conference, where he shows you a vast array of non-secure devices connected to the internet, much of which can interact physically with the real world, including control systems. Here’s his extremely fascinating video, and it’s worth watching all 45 minutes (note that he also has a screenshot of the Endurance Wind Turbine interface that I found in my original post):

OWI-535 Robot Arm with USB Controller from C# and .NET

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I got the OWI-535 “Robot Arm Edge” 5-Axis robot arm and USB Controller add-on for Christmas:



The robot arm comes as a kit that you assemble yourself, and my 3 year old and I had lots of fun putting it together (it helped to have some tiny fingers around, honestly). It comes with a manual controller that allows you to rotate all 4 joints, plus the gripper. It’s fun to play around with, but let’s be honest, everyone wants to hook it up to their computer.

Unfortunately the software that comes with the USB controller works on Windows 7, but “32-bit only”. That was a little annoying, but hey, I didn’t really want to stick with their canned software anyway. I figured I would see if I could get it to work from C#. I was surprised to find a great site by Dr. Andrew Davison in Thailand who wrote some Java code as part of his site for his book Killer Game Programming in Java (chapter NUI-6 Controlling a Robot Arm, which doesn’t appear in the book). Surprisingly he went as far as to do the inverse kinematic equations so you can give the arm a set of X,Y,Z co-ordinates (in mm) in “world frame” and it will calculate all the join angles to get to that location, and then used timed moves to get the arm into that position.

His Java library uses libusb-win32, and that library has a .NET equivalent called LibUsbDotNet. The API’s don’t appear to be the same, but thankfully I managed to find a thread on SourceForge about controlling the OWI-535 using LibUsbDotNet. So, over the course of a couple of nights, after the kids went to bed, I ported Dr. Davison’s Java code over to C# (quite easy actually) and replaced the libusb-win32 calls with LibUsbDotNet API calls. It worked!

Here is the .NET solution that I wrote called TestOwi535. I used Visual C# 2010 Express Edition to write it, so that’s free. Also, you must download and install LibUsbDotNet first and run the USB InfWizard first to generate a .inf file (you have to do this with the robot arm plugged in and turned on), and then use that .inf file to install LibUsbDotNet as the driver (technically you’re installing libusb-win32 as the driver and LibUsbDotNet is just the C# wrapper).

If you right click on the C# project in the solution explorer, you’ll find 3 options for startup object: MainClass is the original code I found in the SourceForge thread, but it’s just proof of concept code and only moves one joint in one direction for a second. The ArmCommunicator class is an interactive console application that allows you to move all joints (and control the gripper and light) by typing in keyboard commands. Finally the RobotArm class is the full inverse kinematics thing. In the last case, make sure you start with the arm at the zero position (base pointing away from the battery compartment, and all joints in-line straight up in the air, gripper pointing directly up, and gripper open). It will do a move to the table, to the front right of the arm, close the gripper, and then move back to zero and open the gripper.

Unfortunately that’s where you start to see the obvious deficiency of the arm: it has no position feedback. That means even though it tracks its position in the code, the physical position eventually drifts away from the internal position tracking, and the arm eventually doesn’t know where it is (it’s just using timed moves). One of the biggest areas where you could improve it is to change the joint rates so that it knows that the joints move faster when going down than when going up.

Still, it’s a neat little toy for the price. I’m going to start hunting around for a way to add joint position feedback, as that would really improve the performance. I also want to rewrite a new module from the ground up that allows concurrent joint moves (this one only moves one joint at a time). Ideally you want to control this thing in “gripper frame” instead of “world frame”.

Happy hacking!

The Psychology of Automation

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It’s easy to overlook the power of human motivation in automation systems.

I’m going to assume you don’t work in a lights-out factory. That’s pretty rare. Almost all automation systems interact with people on a regular basis, and even though we have high fidelity control over our automation processes, people are notoriously difficult to predict, let alone control.

For instance, consider a process with a reject station. Finished parts are measured and parts that don’t meet specification are diverted down a chute. Good parts continue down the line.

Question: how big do you make the reject bin? Naively you might want to make it as big as possible so the operator doesn’t have to waste time emptying it. Unfortunately that means it’s just as easy to make bad parts as it is to make good parts. You’d be better off to make the reject chute only hold 3 parts, and put a full sensor on the chute that throws a fault and stops the machine when it’s fully. Then it’ll be a pain in the ass to make bad parts, and the operator will have a lot more motivation to do something about it. While you’re at it, put the reject chute on the other side of the machine so they have to walk around the machine to empty it.

Consider a machine with an e-stop button. It’s a big red button with a mushroom head that’s supposed to be easy to hit. However, I’ve seen a lot of machines where the consequence of hitting that button was major downtime because the part tracking got screwed up or the machine just didn’t recover gracefully. I once watched a pallet get bumped out of the track and it was riding along the rail of the conveyor. I hit the e-stop just before it was about to damage some equipment. I was scolded for my efforts: “never hit the e-stop,” he said. That’s the wrong motivation. You want operators to press the button when they see something wrong, so make it easy to recover.

Consider an inventory tracking system. You want people to record stuff they’ve consumed, and what cost account they’ve consumed it against. What motivation does a person standing there with a bolt in their hand have to look up that bolt in your inventory system and mark it consumed? Very little. What if you lock the door to the store room and make them request an item before you unlock the door? That’ll help, but chances are some people who don’t know exactly what they want will click the first item on the list, and just go in and browse. What if you make the inventory storage system so convoluted that the only way to find an item is to look up the storage location in the computer? Well, that might work (until your inventory system breaks).

Like water, people tend to take the easiest path down hill. You’re better off digging a channel where you want it to go than expecting it to get there under its own power. Use gravity to your advantage. Make it harder to do things the wrong way and easier to do things the right way.

Safe(r) Data Collection from a PLC

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There’s been a lot of discussion recently about the dangers of connecting automation equipment to networks, and yet there are significant pressures to do so. Of course, I don’t ever think that you should take a PLC and put it on an internet accessible IP address, but it’s certainly common practice to connect industrial automation equipment to internal LANs to facilitate data collection. People in the front office need to push production planning information down to the production floor, and they need real-time data on what’s going on (not to mention for historical data logging, historians, etc.).

It’s all too common to throw a PLC on the same network as your front office, and I’ve seen it blow up. What happens is something invariably goes wrong on the office network (someone plugs two ports together on the switch in the boardroom, or someone brings in an infected music player and plugs it in, or the DNS server at head-office goes down and the local DNS doesn’t work correctly… I’ve seen a lot). However, you want your machines to keep going when this happens.

This is all made worse now that (a) industrial automation equipment is more commonly based on off-the-shelf commodity hardware and software (e.g. windows PCs) and (b) the people writing malware can actually spell PLC now. Up to this point there’s been some form of security through obscurity.

If you have a local IT staff that’s on the ball, you really should be getting them to handle the network layout. On the other hand, if you’re in a small facility with limited resources, there’s a lot you can do by making some simple design choices that will go a long way towards improving the reliability and security of your systems.

Most automation cells now come with an Ethernet switch already built-in. Typically this is an industrial spec. DIN-rail mounted one. It’s not fancy, but it’s supposed to survive in a panel. These Ethernet switches are there to connect your PLC to your HMI, and increasingly to connect your PLC to Ethernet-based I/O like Ethernet/IP, etc. The common (and wrong) thing to do is to drop a network cable from your plant network to your panel and plug it right into this Ethernet switch. This creates some technical problems right off the bat:

The automation devices typically have fixed IP addresses (I personally prefer this because it means these devices aren’t dependent upon an external DNS or DHCP server – two less dependencies are good). Chances are that these IP addresses won’t work on your plant network, so you have to manage those IPs at the plant level. You’re opening yourself up to someone with the wrong IP on their laptop pouncing on your PLC’s IP address, and then bam, your machine is down.

A much better way is to place some kind of Router with NAT between the plant network and the machine’s Ethernet Switch:

Now if you’re just a little manufacturer with two machines out back and your data-collection link isn’t critical, you can probably get away with one of those home routers from Best Buy that you’d use to connect your laptop and your desktop at home to your cable modem. Note that it doesn’t need to be wireless, and you’re probably better off if it isn’t. The way you hook it up is to connect the Internet (Uplink) port on the router to the plant network and run a cable from one of the ports on the LAN side to the existing Ethernet switch in the machine. If your data needs to be a bit more reliable, consider buying some kind of Cisco router with NAT capability (but you’ll be going from the $50 range to many hundreds of dollars – your choice).

Now, when you configure it, you want to make sure that you turn off the port forwarding function, the DMZ function, disallow remote administration, and block all anonymous internet traffic (these should be default settings, but it’s good to check). Also, make sure the router’s local IP address doesn’t conflict with the PLC’s and HMI’s, and make sure they have the same subnet. Typically you’ll want to either turn off DHCP on the local side, or limit it to a range that won’t conflict with the fixed IPs. DHCP is handy when you connect your laptop to the programming port. Now what you’ve done is made it somewhat invisible from the plant side. Some piece of malware scanning for devices on your plant network should just see a black hole.

Now on the PLC side, you can now initiate a connection to the data collection server even though the data collection server can’t connect to the PLC (in the same way that your home computer can connect to Google, but Google can’t get to your PC – theoretically). Note that a piece of malware on your data collection server or on one of the routers/switches in your plant network could intercept this communication, and own your PLC, but at least you’ve significantly reduced the surface area of attack. Not perfect, but reasonable at this time, depending on the sensitivity of your equipment. I’m assuming you’re not enriching uranium or providing drinking water to my community.

(I’m going to be talking specifically about Allen-Bradley products now – sorry.)

So how do you get the data from the PLC to the data collection server? In the old days you’d have some software on the server like RSSQL, and it used a product like RSLinx Enterprise and as far as I know, it initiated the connection to the PLC. That won’t work in this case. Sometimes you’d throw an OPC server in there, and have some kind of historian that would log tags to a database. That OPC server, obviously, needs to be able to initiate a connection to the PLC. To use a router with NAT, you’d need to port-forward from the router to the PLC (or to the OPC server if it was inside the machine network). That’s undoing a lot of our protection.

What you need to do is initiate the connection from the PLC, and have the Data Collection computer act as a Server. One way to do this is with a 3rd party Ethernet card, like this MVI56-GEC card from Prosoft for the ControlLogix line. I have used that in the past to connect to a server, but it involves a lot of ugly PLC coding. It’s your only option if you have to conform to someone else’s protocol though.

If you just want to write data directly into a SQL database, there are 3rd party products that will let you do this (basically a SQL Server connector card).

But there is an option without buying any new hardware. The ControlLogix/CompactLogix lines can send Unsolicited CIP messages, and you can find products that can receive these messages in the PC world, like CimQuest’s NET.LOGIX product. It can act as a server and receive data directly from the PLC – either individual tags, or even arrays of UDTs. The code on both ends is relatively simple, so all you have to pay for is the NET.LOGIX runtime license, which is cheaper than the hardware alternatives. Note that you can also do this with PLC5 and SLC500 devices, though there’s some more effort involved.

I hope that’s enlightening. This is by no means a perfect solution, but it’s reasonable for now. It doesn’t plug the laptop hole (the programming laptop is probably still your #1 vector for malware to get into your machine network). It’s susceptible to man-in-the-middle attacks between the router and the data collection server. It’s susceptible to exploitable bugs in the router’s firmware. Beware and use your own judgement.

Internet Facing Water Management Infrastructure in Texas Exploited Easily

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Completing the trilogy of ICS-security related blog posts, a hacker recently demonstrated how easy it was to find and log in to an internet-facing SCADA system using for water management in a town in Texas. From the article on threatpost:

The hacker, using the handle “pr0f” took credit for a remote compromise of supervisory control and data acquisition (SCADA) systems used by South Houston, a community in Harris County, Texas. Communicating from an e-mail address tied to a Romanian domain, the hacker told Threatpost that he discovered the vulnerable system using a scanner that looks for the online fingerprints of SCADA systems. He said South Houston had an instance of the Siemens Simatic human machine interface (HMI) software that was accessible from the Internet and that was protected with an easy-to-hack, three character password.

For those of us who design, build, and deploy systems like this, let’s ask ourselves what would happen if a serious incident happened and significant equipment damage was done, or worst case, people were seriously injured or killed. Don’t you think the people who worked on the system would end up in court (if not in criminal court, then at least in civil court)?

When in doubt, don’t sit these things directly on the internet. There are lots of secure remote access products available (Google for “VPN”). It’s worth it.

Public Water Control System Attacked

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Joe Weiss recently reported on the possible hacking of a public water SCADA system, apparently in Illinois. This attack, if it was an attack, caused damage to a pump by turning it on and off repeatedly.

It seems obvious that this situation is going to be repeating itself more and more. If you’re a company with industrial control systems, or you provide control system services, now’s a great time to start thinking about your control system security strategy. Do you have the necessary skills on staff? If not, where are you going to source them from?

Finding Internet-Connected Industrial Automation Devices

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I think most people in our industry realize you shouldn’t connect industrial automation devices to the internet, but just in case you happen to think otherwise, here’s a quick explanation why (this is old news, by the way).

You may believe that things connected to the internet are relatively anonymous. There’s no web page linking to them, so how is Google going to find them, right?

It turns out it’s relatively easy to find devices connected to the internet, and it’s kind of like the old movie WarGames where the lead character, played by Matthew Broderick, programmed his computer to dial every phone number in a specific block (555-0001, 555-0002, etc.) and record any where a modem answered. That was called “war-dialing”. In the age of the internet, you just start connecting to common port numbers (web servers are on port 80, etc.) on one IP address at a time, and logging what you find. This is called port-scanning.

It turns out that you don’t even have to do this yourself. One free service called SHODAN does this for you, and records everything it finds at the common port numbers (web servers, FTP servers, SSH daemons, etc.) and lets you search it just like Google. It turns out that (a) most modern industrial equipment is including embedded web servers and/or FTP servers to allow remote maintenance, and (b) most web servers or FTP servers respond with some kind of unique “banner” when you connect to them, announcing who or what they are.

So, if you don’t believe that you shouldn’t be putting industrial automation equipment on the internet, here’s a little experiment you can run:

  1. Take a ControlLogix with an ENBT card and hook it directly to the internet, so it has a real IP address.
  2. Wait a couple of days.
  3. See if your IP address shows up on this SHODAN search page.

You could try the same thing with a Modicon M340.

This query for Phoenix Contact devices is particularly scary, as one of the links is a wind turbine! I was a bit scared once I opened it (it opens a publicly accessible Java applet that’s updating all the data in real-time), so I closed it. There was no password or anything required to open the page. At least the button that says “PLC Config.” appeared to be grayed out. Let’s hope that means it’s protected by some kind of password… and that it’s hardened better than every single major corporation’s website was this year.

Just want to say thanks to DigitalBond for pointing out this SHODAN search for all Advantech/Broadwin WebAccess deployments around the world too.

Control System Security Dilemmas

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It’s fascinating to watch what’s unfolding in the Industrial Control System Security front these days. Digital Bond’s SCADA Security Portal is as entertaining as any (thanks to ArchestrAnaut for pointing it out for me).

A brief recap:

  • Stuxnet makes news even in the mainstream press
  • Siemens shrugs it off and does absolutely nothing about it
  • Security researchers, smelling smoke, start poking around PLC security and find it completely lacking
  • Details about wide open backdoors inserted into common PLC hardware has now been published online

Things are not moving in a positive direction either. Those security “researchers”, many of whom seem to be selling security solutions, are digging up ways to compromise PLCs and they’re posting all that information online. Now if this forces automation vendors to stop looking the other way and start taking security seriously, then I think it can only be a good move in the long term, but you have to admit it feels a little like a tire salesman throwing roofing nails on the road in front of his store.

All of this makes you wonder, what’s a small manufacturer to do? As always, businesses need to weigh the risks and the costs and act accordingly. This isn’t easy for the decision makers. On one side there’s enormous pressure to network all of the systems together to facilitate the fast flow of information between the ERP, MES, and Plant Floor layers, but on the other side, every interconnection increases the risk of catastrophic failure. I’ve personally seen Windows worms take down automation networks. In the next few years I’m certain we’re going to see worms that can jump from PLC to PLC and probably ones that can cross from Windows to PLC and back.

Properly segregating networks and then managing them is a big IT project. That means it needs scarce resources, and those resources aren’t making money for the company. Big manufacturers have enough cash flow (and have been bitten enough times) that they can allocate resources for this kind of project, but small manufacturers are a different story.

Small companies generally lack the specialists needed to implement such systems. Almost by definition, generalists serve in small companies and specialists gravitate towards large companies. Small companies can only implement commodity solutions (unless it’s part of their core business strength). That means that while we’re all worried about what might happen if a major utility or top tier manufacturer gets hit with an automation security breach, the fact is it’s more likely that small manufacturers will be the first ones hit by a fast-spreading generalized threat. The economic impact could be just as large… those small manufacturers are feeding parts up the supply chain, and in this just-in-time environment it doesn’t take much to cause a major interruption.

What’s the solution?

Short of the automation vendors waking up and making secure products, we need better (and less expensive) tools for securely connecting our PLCs. I hate to say it, but you can’t implement modern control systems without knowing the basics of network security, VLANs, and access control.