Category Archives: Software

Automation and Software in the Next Decade

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The “low intellectual property” Fashion Industry as a model for innovation?

I have to agree. Since I’ve started getting involved in open source software, I can tell you that intellectual property laws are the biggest obstacle to innovation that I face. I can say that because I took the time to consult with intellectual property lawyers on everything from trademark to copyright to open source license to software patent. Here’s what I found out: you can’t write a single line of code without violating someone’s patent, somewhere. However, the only time that person will enforce their patent claim is if you’re really successful. The only defense is to pay tens or hundreds of thousands of dollars to build up a patent portfolio of your own so you can partake in a ludicrous arms-race deterrent. On top of that, your patent portfolio offers no defense against so-called “patent trolls”: companies that only own patents and don’t write software of their own. They’re the equivalent of a terrorist cell with nuclear weapons… your nukes are ineffective because you don’t have a city to target.

Copyright is under control, mostly because it’s so much weaker than patents, and it’s free. It stops whole-sale copying of your software, but allows someone to look at your source code, learn from it, and then write it themselves without violating copyright (if they’re careful). Plus, the wide adoption of open source licenses give us lots of material that we can freely copy or integrate.

The irony is that patents were supposed to speed up innovation, but they’ve done exactly the opposite in the software industry.

Do you want to know why none of this matters though? I’m going to make a bold prognostication here:

If the last decade (have we agreed on what to call it yet? The Oh’s?) was about more crap, then the next decade will be about customized crap. Seriously, we gorged ourselves on the mountain of crappage that is sold at Wal-mart and people are starting to wake up with a hangover. We’ve already seen the desires start to change from more to better but I think we’re going to see it change to mine. People are going to want unique stuff. Things that they had a hand in customizing. Something they can use to express themselves.

This has major implications for manufacturing, so it affects the automation industry, and I think it also affects software. Just like the fashion industry, where people use clothes to express themselves, we’re about to enter an age when all the crap you sell to consumers has to have a story, a personality, and be unique. Mass production will remain for your basic staples, and China is going to continue to provide us with that, but North America and Europe are going to have to start producing bespoke crap.

What does this mean for automation? We’re going to see a rise in the build-a-bear style build-your-own-product-on-a-website and have it manufactured and sent to your door the next day. Imagine the logistical changes that need to take place to make that happen. Internet merchandising companies like cafepress already have a leg up in this department. Their merchandise is manufactured after you order it. Now imagine a product with 10,000 or a million different variations, and the automation that has to support it. Imagine the automation required to manufacture products whose specifications change as fast as fashion trends.

On the software side, we’re going to see every major application support custom 3rd party add-ins so everyone can customize their software so it works for them. I think we’re also going to see a rise in “pseudo-programming languages” that let people who aren’t programmers actually customize their applications in ways that we’ve never let them do before. Platforms that give people the power to build solutions to their own needs are going to flourish, and one-size-fits-all solutions like word processors will fade into obscurity.

So I think we’ll have two options: the vast majority of us are going to spend our time building custom things for individuals or businesses. The successful ones will produce products that people can customize themselves.

How Many Times Must I Tell You, “Don’t Repeat Yourself”?

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I spend a significant amount of my time these days doing PC programming (as opposed to PLC programming) and I’d say the most time consuming part of my job is following the DRY Principle, aka “Don’t Repeat Yourself”.

The naive interpretation of the DRY principle is that it’s about minimizing the amount of code you write. While this may sometimes be a side effect, this isn’t the point of DRY at all. What we’re trying to do is structure the program so that there’s just one place for everything, and everything is in it’s one place. This is a lot harder than it sounds because no matter how you segment your program into modules, classes, or layers there’s always something that cuts across those boundaries.

Take logging for instance. Every part of the application needs to log things to the same log file. The naive implementation of opening a file, writing a line, and closing it is short but doesn’t follow the DRY principle because we’re repeating this simple sequence of steps all over the place. The danger is that if we change our logging strategy, we now have to change multiple places in every file.

There are probably two ways that the “logging strategy” could change:

  1. We change where (or if) we want to log the data, like to a database instead of a file
  2. We change the kinds of stuff we want to log

We can handle the first case easily by moving the logging logic into a global subroutine, or if you’re more advanced you would use something like a logging service with the service locator pattern. That would let us change where we log the data, and if we include a severity level with the logging interface, we could filter our logging by severity.

The second case is really hard to solve. We have to choose each spot in the code where we want to log information. Maybe every time I catch an error in a try/catch block, but that means every time I write a try/catch block I have to add a call to my logging service. This case violates the DRY principle because the idea is just “every time I catch an error in a try/catch block”. That idea needs to be codified in one place. Ideally I should be able to extend the try/catch block of the language and say, “any time you execute a catch I also want you to do this”. That’s not possible with .NET, that I know of anyway.

Likewise, maybe I want to know every time a user carries out any action that might affect the underlying data in the database, and I’ll have to add logging code at each of those places too. If you have all of your database access going through a single layer in your application, at least you can confine the logging to that layer, but it may consist of dozens of classes representing dozens of database tables. That’s where we need something like the ADO.NET entity framework, and have all of our database entities derive from a single base class, and then we might be able to tie our logging rules in there.

The problem is that these architectural solutions are hard. They take a lot of effort, and when you just need to add logging, it’s too easy to just go through your code and add logging wherever you need it, and you’ve created a maintenance nightmare. It’s the extremely low cost of copy and paste vs. architecture that creates this problem. If you had to pay $1 every time you copied and pasted code, I bet you’d write more maintainable software.

Phidgets!

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I got ahold of some Phidgets on the weekend. These are basically USB I/O devices for amateur robotics, but I’m looking at their use in the home automation space.

Phidgets Interface Kit 8/8/8
They have drivers for lots of operating systems, and APIs for almost any programming platform under the sun.

Getting the I/O connected and controlled from a .NET application was a breeze, including the Interface Kit 8/8/8 and the little R/C Servo Controller. That little servo could certainly move a damper in a heating duct, and they have lots of environmental sensors. The wheels have started turning…

Software Standards Run Amok

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A few years ago I wrote a program for a customer using a flowcharting language.  It wasn’t just a flowcharting language; the product allows you to use both relay ladder logic and flowcharts.  But the customer had a software standard that made the use of ladder logic forbidden!

Imagine a simplified example.  Do you think Bill Gates’ kitchen has a blender?  Probably.  But it’s probably not like the one you or I have.  Maybe it’s made out of solid gold and maybe it has a nuclear power source, but most of all I imagine it has a fully fledged industrial control system.  Now, imagine we’re programming the control system for this blender.

Of course it would have the standard start and stop buttons, but this blender is top of the line and absolutely safe.  It has a sensor to determine if the lid is closed.  Obviously, if we’re happily blending away and the lid flies off, we need to stop the blender, and it shouldn’t start again until the lid is back on and the start button is pressed.  After all, we wouldn’t want to endanger Bill’s fingers or anything (I happen to know he does a lot of blending).

Many of you have already written this complicated control system in your mind:

ladder-logic-for-blender

Good job!  No matter what happens, the lid will have to be closed or the motor simply won’t run.  Of course, the software specification says that you can’t use ladder logic.

Well, in flowcharting the start and stop logic is simple:

 flow-chart-for-blender

That’s pretty simple, but it doesn’t take the lid closed switch into account.  At first glance, we might have to put the check for the lid closed before every decision block, so we check for the state of the lid switch, then check for the start or stop buttons.  Do you see how this could get out of hand quickly?

Fortunately, the language offers a solution:

flow-chart-for-blender-with-exception

How’s that?  While it’s true that if the lid ever comes off, the motor will stop, we have no way to exit gracefully.  This “exception block”, as it’s called, stops whatever you were doing, turns off the motor and starts the whole process over again.  I’m sure it would work fine for our simplified example here, but what if we were doing something else later on in the flowchart?  What if we were tracking parts, or decelerating an unrelated axis?  In the ladder logic example, the lid switch only disables the motor.  In the flowchart it stops the logic and then disables the motor.

Of course, to deal with this problem in the complexities of a real machine, you end up writing two different flowcharts: one for the sequence and one for the outputs.

flow-chart-for-blender-sequence-outputs

Now take a close look at the right hand flowchart.  It scans through both decisions on every single scan of the controller.  It’s “ladder logic written sideways”.  It’s simple combinational logic that screams to be rewritten in ladder.

In fact, writing the state logic (like auto mode sequences) in flowchart and the combinational logic (like manual mode and faults) in ladder makes a lot of sense, especially for more complicated machines.  So why forbid ladder logic?  Perhaps it was just to force people to start using the flowcharts.

A software standard that bans ladder logic is a bad idea.  Some logic is more readable as flowcharts, and some is more readable in ladder.  For years we’ve had to write everything in ladder.  We were like the little boy who only had a hammer and thought every problem was a nail.  If that boy suddenly traded the hammer for a screwdriver, was he any better off?