Control Panel With Discrete PIDs vs. Computer / Automation?

 

Brewing an experimental beer in The Electric Brewery

 

Introduction

We get asked all the time why we didn't consider using more automated PC solutions, microcontrollers (i.e. Arduino, Raspberry Pi), or specialized PIDs in our Electric Brewery control panel to control our brewing process instead of standard PID temperature controllers. Specialized products such as BrewTroller (discontinued), BCS-460 (discontinued on and off), BrewPi, and others exist too that are targeted as the 'heart' of a brewing setup. We looked at all of these solutions when designing our setup. New ones are coming out all the time too. They tend to come and go.

Our FAQ answers this partially but people still keep still keep asking for more details, or more exactly, they keep asking us what's right for them. That's a question we can't really answer as everyone's needs are different.

What we can do however is provide more information into the thought process we went through when designing our Electric Brewery control panel that eventually led us to choose discrete 'standard' PIDs instead of other, possibly more automated or specialized control systems such as a computer based touchscreen, or an embedded controller such as BCS-460 / Brewtroller / Arduino / etc. These were all options we considered.

 

Our background

Sticking things in electrical outlets

Growing up we were always heavily into electronics and computers and spent hours breadboarding and building circuits and programming on various computers (ZX-81, C64, etc.). Choosing a career as an electrical engineer / software developer was the only one we were ever interested in.

In a previous career we spent nearly a decade at a large multi-million dollar automobile assembly plant designing process control systems used by operators and technicians. This gave us a lot of experience with human machine interfaces (HMI) of various types (Windows, Linux based, QNX and other real-time operating systems, custom embedded I/O hardware, PLCs, etc.). We had basically unlimited budget to play with any technology we wanted to (fun times!).

Some of these systems were controlled using simpler buttons and controls such as what we have on our brewing control panel, while others used advanced touchscreens meant for harsh environments. Other systems used in the front offices used a regular keyboard and mouse with a web interface. One of the more interesting ones used cameras for image pattern recognition, a type of artificial intelligence. It garnered a lot of interest from the corporation and was eventually featured on the cover of the March/April 1999 issue of Manufacturing Automation magazine.

The people who used these systems had various skill sets: Some had fairly advanced programming skills themselves, others had never seen or used a computer before, and some could not read (which posed some interesting design challenges). We saw first hand what worked and what didn't by watching them use the tools and interfaces we built. We were lucky to be able to work on such varied systems. It helped enormously when it came time to design a brewing setup.

 

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Points to consider when designing your control panel

As you read through these points, remember that our goals may be different from yours so it's important to assign weights using your own goals and decide for yourself what's best for you. There's really no right or wrong answer here. The points below are things you should simply consider:

Industrialized

One of our design goals was to try and build a brewing setup that was as industrial as possible and be able to use it on a plant floor in wash down conditions. At least NEMA 12 (water resistant) if not NEMA 4 (watertight). We didn't want to have to be careful with it. We didn't want to have to treat it like a normal PC or laptop and keep it in the opposite corner and wipe down our hands before using it. If we couldn't use it with wet hands, gloved hands, hands covered in sticky grist we didn't want it. (That said, we rarely get dirty when brewing but our hands are often wet).

Industrialization is possible with all solutions. Going with a computer based solution would have meant using an industrial ruggedized PC touchscreen or similar (we've designed around these in some of the plant floor systems we've built years ago and see the abuse they get). So it's certainly possible. The only issue is cost. A proper ruggedized touch screen PC (or screen with the PC in a rugged enclosure) isn't cheap. On the flip side standard PIDs / switches / lights are easy to get in industrial / water resistant form for cheap.

Interface

We love the open ended customization available with computers. You can do anything you want. However the more we designed our brewing process (make sure you do this first and have that down pat before deciding how to implement the process), the more we realized that the controls and custom user interface we'd be creating would be starting to mimic "old fashioned" dials / displays / controls. Computer based solutions are infinitely more flexible but we didn't find that in our case we really needed more than what we could get with standard PIDs / controls / lights.

For more information on our brewing process, see our Brew Day Step by Step guide that walks you through a typical brew day with dozens of pictures and videos.

Ergonomics

Using a physical switch or button with tactile feedback is always easier for an operator than a touchscreen where the only feedback is visual. When you flip a switch you know from the motion that the action is completed. When you poke a screen with your finger you need to watch and make sure you've poked the right spot and that the action was registered. No different than typing on (say) a tablet versus a real keyboard. Try writing an essay on an iPad instead of a PC or Mac with a real keyboard. There's a reason real keyboards have tactile feedback and probably always will.

So when we design user interfaces, if we can do it with something physical we do that first if possible. If there's too much variety between screens or functions then you have to go touchscreen (we do this with our home theater remote for example).

You can mix the two as well sometimes: Use the screen for display only (not a touchscreen) and still use discrete buttons. This was an option we considered for our control panel. We've done that in the past with assembly line systems where an operator needs to poke at a button every minute. You don't want them doing that to the same spot on a touchscreen as it will eventually wear out and screens are expensive. Give them a physical button (like our red alarm reset button). Less likely to wear out and if it does, you replace the $10 button in quite literally 2 minutes. On the assembly plant floor, we were often sending electricians in during the 15 minute breaks to change out a switch or button quickly.

Flexibility

Touchscreen computer based solutions win hands down for flexibility. If you're not sure of your brewing process or think you may want to experiment and/or change it in the future, a touchscreen lets you add or remove controls easily if you keep it all on the screen. If you design correctly from the start then we really don't think it matters. We've been using our PID based setup since 2009 and if we had to built it over again we'd do it the same way.

Brewing has been around for thousands of years. We doubt that in the next 10-20 years we'll be doing anything radically different in our process that would make us want to redesign our control panel. By keeping our setup flexible even newer processes such as hop stands (used by new popular beers like New England IPAs) that we had never envisioned before are possible.

The flexibility afforded by computer based solutions is a double edged sword so we caution brewers to not fall in the trap of creating something half finished that more or less works, and stopping there. We see this far too often: A setup that works but has a bunch of quirks, bugs, or usability issues that never get fixed over the years. Some of the commercially available systems are even known to have such issues if you talk to the owners.

Long term serviceability

This was a big one for us and was probably the biggest driver to going with the solution we did: We wanted our setup to last us for the rest of our life.

We're more interested in the art / craft of brewing than tinkering with equipment. While we may be a geek / nerd at heart, when we brew we just want to brew. We don't want to fiddle with equipment, debug / recompile code, or wait for a firmware or Windows update before we brew. We figured we'd spend a year or so designing something that could brew anything and then just use it forever. So part of our requirement was to make sure that if in 1-2 years (or even 10-20 years) we needed to replace something that it be easy to do and possible.

We did not want to have to depend on one company to do the work or supply us with a specific part or update the software for us. We did not want to depend on any company to still be in business. Nor did we want to have to remember how we configured something many years down the road. To accomplish this, we wanted to limit the use of any special or proprietary parts. Parts had to be hot-swappable. Pull the old one out, put the new one in.

All of the parts used in our control panel, heating elements, and other components are all extremely common. They've existed for dozens of years and they will continue to exist for dozens more because of the tens of thousands of (non-brewery related) industrial installations around the world running today that rely on them. We're not married to one particular part or manufacturer. If (for example) a PID dies in 20 years we can buy any similar PID from any manufacturer and drop it in as the functionality will be the same. There are hundreds of choices. It does not necessarily have to the same manufacturer at all. The hole sizes are all standard understood manufacturing sizes (1/16 DIN for PIDs, 23mm for switches / lights, etc.) because the industry that uses these parts demands quick and easy serviceability. It really is: Pull the old one out, put the new one in. Same with our heating elements. There are dozens if not hundreds of models to choose from as they are used in millions of hot water tanks around the world and all use the same size hole. We did not want something like the proprietary Blichmann Boil Coil that requires two non-standard sized holes in the kettle. If a few years down the road we need to replace a Boil Coil and it's no longer available, we need to replace the kettle as well or find a way to plug those holes. (more thoughts on the Boil Coil).

On the control panel side, some of the custom controllers available are not open source and are owned / run by one person and come and go. For example, BrewTroller hardware is no longer available after only a few years. That should give anyone pause. If both the hardware and software was 100% open source then that may be different, but even open source stuff comes and goes in terms of popularity. Where are some of these products going to be in 20 years, let alone in 2 years?

Long term serviceability is also an issue with many of the commercial setups we considered. Take the Sabco BrewMagic setup. At the time it was only gas based so that was a non-starter, but equally important is that it runs custom (patent pending) PLC software that only the manufacturer have access to. Nobody else is allowed to share this software or copy the design as it's patented. It is not available for download. You can't take a backup. What happens if that PLC dies down the road and the company is no longer around? The system is dead in the water as their software controls absolutely everything.

Interest in craft beer is at an all-time high so everyone is out to make a buck. There are dozens of upstart companies popping up every year. Most do not survive. Take BrewMasterControls. Based on the last of responses to their customers on online forums and on their Facebook page, they appear to have folded in the summer of 2013 after only a year or so in business, leaving customers of this custom programmed multi-thousand dollar electric setup without any support. Some of them never even received the software to make their system work!

Our website on the other hand provides anyone building our brewing setup a complete list of standard parts, assembly instructions, and even wiring diagrams. Readers may download our book and effectively have an offline comprehensive service and maintenance manual for life. No other brewing setup comes with this level of detail.

What about a computer based setup you program yourself? You may have a software developer background (like ourselves) and not have any issues coding your own custom software which you can then support yourself. You could use a flat panel ruggedized PC and capture information and run devices using specialized control software. This problem is not the code you write yourself, but the out of the box software and drivers around it: What if they are not kept up to date and in 20 years do not work on Windows 22 or whatever people are running then? Even if you keep software backups of everything, what if hardware dies? Drivers for newer hardware often do not work with an older operating system. What if the specialized hardware is no longer available?

Think of the computer you were running just 5-10 years ago, let alone 20 years ago. Had we designed a PC based brewing setup 20 years ago it probably would have been done with ISA or VLB capture cards and serial / parallel port technology. None of these are found on computers today so the system would have to be redesigned if something was to fail a few years down the road. The pace of computer technology is increasing so it's only getting worse. You should assume that much of the computer equipment you purchase today will no longer be available in 1-3 years. That's just the way the PC industry works. Embedded controllers are no different. They come and go as well. BCS-460/462 were popular for a while, but then they stopped making them. Years later BCS-482 was announced. How long will it be available for? Who knows.

Data logging

The OCD in us loves the idea of logging temperature graphs and all those things that computers lets you do easily and basically for "free". (No easy way to do this with standard PIDs). You can track all sorts of things over time.

But then we started thinking: What exactly would we "do" with this data? We know how fast a PID based setup ramps. Just use the timer once to time how long it takes to ramp up. Why do we need to know exactly how that ramp curve looks? Does seeing the curve of temperature over time really give us information that we can use instead of just knowing the start / end points and time? You also can't control the curve. We want to step as fast as possible, not slowly go up. So every beer will have slightly different ramp times as the amount of grain and water will be different. You can't assume the ramp results from a 5% ABV batch will still happen with a 7% ABV batch.

Whenever people talk about all the logging they can do we always ask "So how are you using that data to make your beer better?". We couldn't think of one example of how we'd use this extra data so we decided data logging doesn't help us. Your needs may be different however.

Level of automation

This one's a no brainer. If you want or think one day you want to go for semi or complete automation (push a button and wort comes out), a computer based or similar solution is the way to go. Standard PIDs won't give you this as easily. Computers can replace more than just PIDs and can do all the other things you'd want for full automation like control pumps and valves.

We didn't want semi or full automation so going PID was still in the running. The level of automation is one thing that we didn't actually think about very long at all. We knew right from the start that we didn't want semi or complete automation. We wanted to keep things 'simple' with what can best be described as manual dials and controls for 2 reasons:

  • So that we feel like we're doing something on brew day (it's a hobby and we want to be part of the process steps instead of having a computer manage them)
  • The time required to program the automated steps at the start of the brew day could or would likely take just as long as 'manually' changing certain settings when needed. For example, when step mashing followed by a mashout, we hit the temperature "up" button a few times on one of the PIDs once the alarm sounds to let us know that a mashing step is complete. It takes 3-5 seconds to do. A computer could easily automate this but what exactly is that saving or simplifying for us? Computers are great for extremely repetitive processes and where actions must be done at very precise moments. In brewing there are only a few step mashes at most and timing is not critical. If you mash a few minutes or even an hour longer after conversion has already taken place it won't affect the beer.

Remote control / monitoring

One feature that some of the computer based solutions are known for is that you can view your controls from anywhere using an app or web browser. Maybe it's just us, but to this day we still don't understand why we'd want to do that on a properly designed and implemented system. We know how our system behaves so we have no need to monitor it. We have timers with alarms to let us know when something needs to be done.

Most of the steps in the hot side of the brewery (the wort creation process) are not extremely timing sensitive. For example, because of the way the enzymes are converted as we mash, a brewer always moves from lower to higher temperatures. Temperatures need to be held for a minimum amount of time for enzymes to convert. There is no maximum time as mentioned previously. If enzymes are properly converted after 2 hours but you did 3, it won't make a difference (good or bad). Up until the boil, timing is not overly critical in any of the steps.

When an alarm goes off, you usually don't need to be on top of it immediately. For everything prior to the boil we're usually not in the room and will often let steps run long. Boiling is the exception as we want to add hops at the right times (more or less). Even here, missing a hop addition by a few minutes will not result in a difference that is noticeable. By the time boiling is on, we're in the room for good as we're cleaning up the mash tun, cleaning fermenters, etc. All the things that require human intervention and cannot be automated.

If a system needs to be monitored because there's a fear that the system isn't going to run right then it probably isn't designed right to begin with. Implementing controls through the internet is easy to do on any PC or embedded controller based setup as you basically get this feature for free. We just think this is one of those 'cool' features that is neat the first time you see it but adds little value at the end of the day.

Some brewers also like to be able to remotely control their brewery. This is something we was never interested in as we feel it's inherently dangerous to remotely control something as powerful as a brewing setup. You might turn a pump on remotely but not realize that (a) it isn't primed properly and you're killing it, or (b) you didn't hook the hoses up right and near boiling water is now splashing all over the room (what if someone else was walking by?), and so forth. We've had friends 'pocket dial' us on their smartphones because they forget to lock it. Could you imagine mistakenly turning on a brewing heating element from across the country and not realizing it until the fire department calls you?

Brewing setups are inherently powerful and dangerous. We think there's something to be said about always being in front of them to press buttons, change settings, and so forth. Usually when we want to change something on the control panel, we have a quick hose swap or valve adjustment to do as well, so being able to make a change to the control panel remotely doesn't help us as we need to be the room anyway.

'Bling' factor

This can most certainly be a design goal. There is nothing wrong with that. If someone wants to go for the 'wow' factor then we think both a touchscreen setup and manual dial / switch / PID setup can be made to look pretty impressive. A touchscreen setup can likely be made to look more modern with on screen dials, controls, and process pictures (even animated). A PID based setup can be made to look more industrial / ruggedized with rows and rows of physical dials / lights / switches. Almost 'retro' in a sense. Depends what style you like.

Complexity to implement

Because of the flexibility, computers based setups have a greater learning curve and you will need to know more about low voltage electronics and programming / coding if you want to fully harness the power of what they can do. None of these was a factor for us as an electrical engineer (we're comfortable with this stuff). The same may not be true for others.

 

Conclusion

We didn't see how a computer based touchscreen or similar microcontroller based setup would add any value for our design goals and it would actually impede many of our most important goals. We'd end up with something that behaved similarly, would have cost a bit more, and may not have been as serviceable in the long run. The key word here of course is our. Set your own goals and decide. Please don't let someone else decide what's best for you. No matter what the marketing folk will tell you, there is no "one" universally best control panel setup for brewing.

Hope this helps someone on the fence.

Questions or comments? Visit our Control panel with discrete PIDs vs. computer / automation? forum thread

Ready to start building? Check out our Building Your Brewery guides.

Cheers!

 

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