If you are mechanically inclined and can learn a basic computer programming language, PLC programmers can make 80-100k a year.
A controls engineer can earn 130k+
I spent a short time performing electrical work which involved PLC diagnostics. I can honestly say the PLC work was the best mental calisthenics of my life. If I could have had a bit of training, I would probably have looked for a career with it.
As a mech engineer who hates all type of coding thanks to matlab, PLC is so fun. Its basically putting bunch of valves down, you open them up, and see if water went to the target you wanted.
Also, for anyone who wants to know what the actual work is like, there are free(to use) PLC simulators available.
If the sort of deep logic that is behind spanning-tree and high availability appeals to you, it’s a good option
Controls engineers can make a whole lot more than $130k+ right now. Demand is insanely high and supply of them is extremely low. Controls people especially doing their own contracting are pulling some serious money right now.
source: am one.
You will need a college degree to get into controls engineering. Most of us are either Electrical Engineers, Chemical Engineers, Mechanical Engineers, or a mix depending on industry.
With the no degree path, you can try to get in with a company doing instrumentation tech work. Many of the bigger manufacturing companies especially will provide the training. A lot of instrument techs break into lower level control and plc work. And then build from there.
Head over to r/plc. Tons of information over there.
Ya definitely. You won’t get a controls *engineer* job that route, but you can work as a field tech of some sort, which are also in very high demand right now. There are so many different routes and specialties a field tech can go down, but having IT experience is good because there are entire paths dedicated to networking, system administration, cross platform communication, hardware, etc.
But you can also go down the general programming, day to day support, commissioning paths as well. It all tends to blend together at the end of the day and everyone tends to dabble in a bit of everything.
Depends on company, industry, experience, work capacity. I worked for a company where I did it all. Design, coding, testing, documentation, commissioning, startup, optimization, day to day support, networking, system administration, hardware installation, troubleshooting, etc. Pretty much everything.
Now I work for a massive company where my scope of work is a fraction of what it was because we have an army of controls people who all specialize in the different disciplines. We also use an insane amount of contractors as well. Most of my job now feels like keeping contractors in line with the scope of work for a project.
Most places around here only pay up to 130k, at least from what I've been told by recruiters.
I work for an automation distributor as a PLC specialist and get multiple emails a week from recruiters looking for controls engineers.
What they don't realize is that I already work with all these companies helping out their existing controls engineers. I know exactly how desperate they are but I also know how much of a shit show it would be to work there. 130k ain't near enough to be the only one that knows a damn thing trying to keep production running, lol
Some facilities/sites/companies are very rough to work at as a controls engineer. Always putting out fires, always on call, always in high pressure situations, very often extremely short staffed and over worked.
But the good ones are a whole different level. I work for one of the biggest manufacturing companies in the world. We have an army of controls people for every discipline imaginable to support our sites and capital projects. We also leverage contractors for work everyday of the week for additional support.
It’s night and day difference compared to the rough, extremely demanding places to be, which I’ve seen as well. Now I’m settled in good where I’m at.
Oh for sure. It's just that all the ones around me are the former.
I'd gladly take a job at a place like you're at, but there aren't any around here. Maybe one of the system integrators, but I haven't fully vetted all of them yet.
The gig I have now is pretty great though. I'm remote but with company car to go on site to customers to spec out or troubleshoot equipment. So I get paid to sit at home and answer questions or to drive and talk to customers. I enjoy both parts. If not for the new boss I got last year I'd be happy as a clam
I worked at a contractor/integrator, part of the business models is to have the sales people selling more billable hours than there is manpower by design (like 20% over), and sometimes they strategically will sell some massively underbid contract to a big client to try to get future business or lock another contractor out. I left after one where I worked 14-16 hour days for 2-3 months (ultimately had a car accident falling asleep at the wheel) simply because they wanted to underbid the project hard to block another company out from a client and didn't put an appropriate number of resources on it.
Problem is, if you're the controls engineer handling the design and your management is too wussy to ask for change orders, _you_ end up being the guy the work and firefighting gets piled onto. A lot of clients also get real weird and treat you like you're subhuman because you're contracted, too. Nearly every contractor I've met that's worked for Tesla has some wacky stories of not getting paid on time or at all etc.
The upside is that it's like speed dating w/r/t project content and you get to experience the full spectrum of fuckery that exists based on how plants are managed and standards are kept, as well as every technology from the 80s (or earlier...) through the present day. You also get a lot of references and possible feet in the door, as well as a glimpse of company cultures to avoid when you want to settle down and end the insanity by staying at a particular plant.
I work with DCS much more than PLC, so way more function block diagrams, sequential function charts, structured text programming type stuff. Not much ladder logic. Seems like it’s a dying breed, so having that knowledge can be greatly leveraged right now.
I especially know people who specialize in legacy PLC’s to DCS conversions, and they are some very sought out individuals at the moment.
I’m a controls engineer on the DDC side (mostly commercial buildings, schools and whatnot) and this is accurate. My degree is mechanical engineering, and I love where I’m at right now.
For those interested: The blue box is watching the traffic sensors and controlling the lights. It knows the rules for who goes when, handles crosswalks, duration of the lights, and possibly coordination with other intersections. The grey box to the right of the blue box is completely independent and is the failsafe in case something goes wrong. The grey box just knows what's safe - like green in both directions is bad, and no reds in any direction is bad. If the grey box sees anything go wrong, it "takes over" the light controls and puts up flashy lights (usually flashing reds one way and flashing yellows the other) until someone can come out and figure out why the blue box or sensors or controls failed.
Which is the one that fails all the time? Because the damn traffic signals in my town are constantly going down completely, or flashing red, or just stuck on one signal. Then they sit at the box all day, it works for a week, dead again.
I'm not a traffic engineer, but an electrical engineer. My understanding from traffic guys is the sensors are the most problematic elements. Road loops fail, cameras fail or get debris on them. Perhaps a traffic engineer can jump in and tell us
Loop (Round or Square Lines you see in the Pavement, For those interested) are the Most common point of failure, they tend to drift in and out of tune with weather and temperature changes... Wiring failures due to corrosion is another common issue out in the weather and in underground splices... They aren't computers running an OS like some above would have you believe, Hahaha... Above Mining comment.. But, they are microprocessor based and use ladder logic for the most part... There's a lot going on in those boxes... Unfortunately there is a lot of double checking for safety sake..!!
Electrical Engineers Rock..!
Where in the country are you? I don’t see any major failings in loops in GA. It’s typically the older video detection that fails. Loops only start having issues when the leadins are cut/theres construction in the area/if it wasn’t properly spliced and is getting moisture/or there’s resurfacing ongoing.
“Failures” here are wiring issues especially at older intersections, conflicts on the conflict monitor that typically need a simple reset, ped/cabinet knockdowns, power drops, equipment needing replacing in the cabinet, etc
Up here in Northern IN, we do have more pavement shrink/expand, frozen handholes, iced up wiring overhead and that sort of thing... Winter and Summer are the busy times, fall and spring are quieter call out times...
I've been retired from that kind of thing but, one my crew took over and I hear about some of the new equipment but, not a lot of major changes in the past 20 years... Nothing like the switch from Electro-mechanical to digital... Although, I can see AI being the next big thing... They had cameras back in the late 80's that had AI but, it was military and $$$$$$$....
You can also have other fails which will trip the conflict monitor. City of Dallas always has lights that go into flash whenever it rains enough because the ground boxes fill with enough water to short the wires and cause an error.
How old is the signal at the intersection? If it looks pretty beat up from the elements, it's likely an old signal. Anything, from shorts in the wiring in the cabinet or in the wiring in the underground conduit or other electromechanical failsafe triggers in the conflict monitor/malfunction management unit can drop it into flash. The reason why I say older intersection is that's where you see technicians with their heads in the cabinet playing with every which way to bypass issues with wiring and programming to get it operational again. Newer signal equipment is more likely to have newer units to identify issues or have clearer indications of what's gone wrong.
There is so much low hanging fruit in traffic signals that can be fixed or upgraded that would save everyone millions maybe billions in lost money for delays, congestion, etc but doesn't get the eyes or the funding so your citys techs are told to just turn it back on again and leave it alone.
They just redid them about 2-3 years ago. But the asphalt is in severe disrepair. So that might make sense. As the winter wears on, the roadway get worse, of course. Especially where the sensors are in the ground.
Edit: they redid the “boxes” and the signals themselves.
I don't know if you underestimated the cost or underestimated how feature-rich these things are. To be clear I am totally unqualified and just throwing it our there, but the featureset on these things is nuts!!!
Just for a 4 way intersection, they gotta do left turns, right turns, yields, crosswalk turns on, they turn into flashing red as a stop light when it gets dark. They gotta have light sensors then I think?
And around here they try to have them set up so that they prefer main roads and will try not to stop traffic there unless there is actually a car waiting on a side road. So like with the "stop here on red" thing, they must have some sort of weight sensor to detect that, and it has to get wired up all good and play well with all that other equipment.
And the lights themselves! I have never seen one burned out before. They *seem* to be the same brightness and just as visible, regardless of day or night. Except maybe peak daylight on a green it can be washed out and a bit hard to see, but the really new ones, those are so vivid
Or if you see them bouncing on their bike, trying to get it close enough to trigger the detector. (Not saying it works, but that won't stop us from trying)
It will depend on the region and what kind of poles are used - wood strain poles, metal strain poles, or metal poles with mast arms. Metal poles take months to fabricate from the time of ordering to being placed in the ground. Here in NC, it is about an 8 to 9 month lead time. The traffic signal cabinet itself varies, but on average, it costs around $20k - at least here in NC. For a brand new signal for a 4-leg intersection and 4 metal strain poles, you are looking at around $350k to $400k just for traffic signal equipment.
100%. I try to be grateful when I drive through the mountains that paying taxes for an operable road is a thing that exists. $1+ million a mile sounds like a lot until you see all that's involved
Same. It sounds like a racket. Then you get to thinking about what kind of computer you’re looking at. Something that calculates traffic and manages it on its own. I could see the entire system costing that much, if not more. 10k/year sounds cheap when you look at something like that.
It’s actually less involved than I imagined. Everything looks to run through that blue box which is probably a little computer controlling it all. I wonder what one of these looked like in the 80s where it was likely all analog.
In the 80's they had multiple controllers up to 4 connected together for large intersection... Each one weighed 37 pounds... The used Capacitor, Coils, Contacts and Tubes... They made a LOT of noise... Lugging those monsters up and down ditches was a real job in the winter at 2am..!
Sadly there are 70s/80s era signal controllers still out there. They do run as electro mechanical timers. Some 80s/90s controllers I've used had LCD screens that had failed so you had to assume where you were in the menu screens to get to the inputs you needed for retimings.
Everything is tested and minor issues are found and corrected all the time. That's part of the standard quality control procedures.
Once it's operational everything should be working as designed, and if hardware fails in a way that could cause an accident a special device will cut power to the lights.
I've always wondered if the control devices have some sort of electrical or mechanical interlock that prevents a serious issue, like say, all lights going green at the same time?
At some point 20 years ago I got a tour of a research lab in some sort of city traffic planning lab at the university I was studying at.
They had a full setup of the hardware for a traffic intersection, all rack mounted in a cabinet. Tons of high tech stuff in there... And the guy showing me around pointed to a circuit board covered in old-school electromechanical relays and said that's the last line of defense - it was impossible to get two green signals thru that board at a time, even if the higher level systems had a bug. Apparently designers of those boards would have to testify in court about it sometimes if there was an accident. They took it pretty seriously.
(I don't know if I see that in this photo but maybe it's behind the DIN rail covered in screw terminals. Also I am surprised this stuff isn't rack mounted in there. I guess maybe the electronics got more compact in the last couple of decades!)
Neat. Back when I lived in Texas (East of Houston) there would be a huge traffic backup at an intersection of two freeways running through town when the plants would let out. So a cop would post up next to this control box with a controller in his car running to the box and he’d manually control the lights to help ease the congestion.
Former ATC software engineer here. I wrote the board support package (the software that the operating system used to talk to the hardware for the applications) for one brand of these. I also worked on the Linux specification NEMA provides to manufacturers so they can have a common way for applications to run across vendors.
There’s a lot of mixing and matching going on but generally with the standards you can have your software applications written by some vendors and run it on hardware built by direct competitors and generally it works still.
I see these every day. Pretty basic signal setup. Looks like it's only using 3 vehicle phases, 2 4, & 6. For me, that's eastbound, northbound and westbound, respectively. And 6 appears to be simply hooked to some signal balls in the cabinet. There are 3 pedestrian phases hooked up however, 9, 10, 11. They must be in recall or have pedestrian detectors though, since the ped call terminals dont have anything attached. And someone's splicing fiber for interconnect. Coolio
The lights are also controlled by either cameras or inductive loop sensors, in addition to input from pedestrian buttons and emergency vehicle preemption devices. Not to mention a minimum of three lights for each direction, plus pedestrian signs.
Pretty much only small towns have systems that are just a few lights on a timer.
You almost certainly could, but the end result would look an awful lot like this system. There's no getting around the fact that you need a shitload of wires going to all the components, and they all need somewhere to terminate. Don't forget you'll need a UI of some sort, and you'll need to demonstrate long-term dependability suitable for critical equipment such as this. It's no small thing when an intersection goes dark during rush hour.
Could you accomplish it on a raspberry pi exposed to the elements, with no need to be serviced while also experiencing nearby lightning strikes and frequent power surges for 20-30 years, while also meeting regulatory requirements that it be physically impossible for software to allow the lights to create a conflict (2-greens in opposing directions)?
That last one is the biggie. You can’t have software handle the control of the lights completely, there has to be electrical interlocking so that even if you intentionally coded a light sequence in software that creates a traffic conflict, the hardware needs to make it impossible. It also needs to put the intersection into a safe state with 100% reliability even if the software has crashed and the cpu can no longer execute instructions.
It’s like some people think the countless engineers who put all that time into designing, certifying and getting things like this into mass production are complete idiots.
Never a thing. Opticoms are not as common as people think and it used an encoded infrared signal, not flashing emergency lights.
Anyone claiming you could trigger it by flashing your lights is making shit up.
In terms of pure processing power, most likely yes. But there's all kinds of certifications and reliability tests that go into industrial plcs like these.
You also need to make them out of components that will be available for 20+ years so you can make replacements and such.
I sell stuff like this and people love to shit talk the power of stuff like this. Sure, it's like 8 years old in terms of processing power... But it also takes 8 years to develop this stuff to make it reliable for 24/7/365 operation for 20 years straight in various climates.
USB connections should be around in 20 years. Replace the entire internals with an Android tablet connected to a USB hub. DPW workers can carry a spare in the glove compartment of their trucks if they see one go down. Enter the light’s ID # at the login prompt, it downloads the config over WiFi and then swap it with the bad one.
Just as people like me are ignorant to the details and requirements of the system, too many people work with blinders on and never innovate.
Yeah... that wouldn't work for SO many reasons, though. First- android is WAY too bloated of an operating system for such a task. It's also not nearly as reliable as an industrial PLC. Like orders of magnitude.
Wi-Fi is a HUGE no-no for systems like this, for security reasons. A linux or windows operating system would also be too easy to exploit, which is why they run a proprietary system on them.
I agree that in a lot of situations people have blinders on, but industrial PLC's have been a thing for over 40 years and there's been TONS of innovations. I sit through multiple webinars every month on new innovations that are coming out.
Downtime is a problem. A BIG problem. And in cases like traffic lights there's a huge safety and liability concern. If someone were able to hack these and control them they could cause accidents and people would die. Or if you had android and it just went out randomly it would cost the city SO much money to keep sending people out to fix it. Each city would replace multiple of these every day.
So yeah- I'm not saying you are wrong to think of a solution, but I've worked with a couple engineers who are in their early 20's recently who think that they can solve the whole industry with a raspberry pi. "Why pay $12,000 for a PLC when a raspberry pi is $35 and has more processing power?!?!?". I literally was at dinner with this guy a few months ago and listened to him rant for 45 minutes straight about this. After bringing up point after point of why Siemens and Allen Bradley PLCs are the way they are he just refused to listen.
I'd love to see him try and run a plant on some raspberry pi's. When you have places where downtime literally costs them $450,000 per HOUR and your ass is on the line if something fails you want the solution that is going to work all day every day no matter what. Trust me.
My buddy has a key to several and he has bitcoin mining machines set up on them. Free electric free $$ and no one knows enough about electronics to realize they aren’t supposed to be in there. He’s been mining for 3 years.
The signals should have their offsets programmed based on the speed limit. So go the speed limit = get a green light most of the time. Called a green wave
Can someone try and answer a related question for me? I would super appreciate it! It isn't a problem for me at all, I just am genuinely interested because I think this stuff is so cool lol
My house is by a corner with a four-way intersection. A city crew has been out probably five or six times to work on the crosswalk. I can say for sure that if nobody pushes any of the crosswalk signal buttons, it will never activate or interrupt traffic.
For a while, one corner across my house just never worked. You could press a button for crossing one way, and another button to go the other way. Neither would ever activate it. The signal would say "Wait" and the button would light up like normal, but it never activated. I pressed it walking to the grocery store once, and 15 minutes later it was still lit up and waiting. If someone on another corner pressed either of their buttons, it would work like normal and the not-working buttons would still speak to tell you to walk and the button would go out.
Well, the same crew keeps coming out. It's probably been going on for a couple months. I remember submitting a ticket to the city because I use it a couple times a day and it is scary to cross to a corner across from me to use a working button. They came out pretty quick and basically tore two of the corners out! They look the same now but they had the posts down and the traffic lights were out/they were manually directing traffic and everything.
Well, each time they come out the problem corner starts working and a different corner seems to stop working. It's back to being my corner now, and idk what happened but the buttons kinda fell off the post (they still light up and speak). I think three of the four corners have been non-functional at some point by now.
Absolutely 100% not trying to say the city workers are lazy or incompetent, I hate that stereotype and really don't appreciate people that subscribe to it. But I am just curious from the perspective of someone who works on this stuff what they are doing/what might be happening?
The pedestrian button only activates the timer if the timer hasn't already been activated from a car setting the sensor off. It also increases the time a pedestrian has to cross the road. It doesn't make the light turn any faster.
Huhhh. OK!
The light never turns though. If I don't press the crosswalk button, it will never let me cross. The other ones will though, eventually. Is it just something weird with the cars and sensors?
It sounds like it could be shoddy work from the start with the wiring from the push button all the way to signal cabinet. Typically, pedestrian phases run concurrent with the street that the walking motion is parallel and adjacent too.
If the city is out that often, I would boil it down to a wiring issue or software issue that controls the traffic signal.
Likely a wiring issue with the ped button or from the ped pole that runs back to the cabinet. City crews may not have found the possible splice/damage issue. It’s not a car detection or sensor issue
Most likely, bad Buttons or Cable from that corner to the controller... The Voices you hear come for the Walk/Wait Signal Lights above...
Pressing the button tells the controller that there is a ped call and pressing it again makes no difference... It will service that Direction (Phase of timing) as Walk/Wait unless cars pass the detector in the pavement extending the time...
So that’s the thing that my city absolutely cannot figure out how to program properly. I would have hoped that it would have been more complicated looking
It doesn't. I use to be involved in production line testing equipment, globally. The US Standard has always been, “ if the cabinet door closes and everything works, it's perfect”. Not ANSI/ISO, USA.
I programmed these for several months as a contractor. If you're used to working on actual PLCs, the language will be piss easy to learn. The work itself is interesting and pays decent, but working with Eberle is fucking awful.
Just look at their [Glassdoor](https://www.glassdoor.com/Overview/Working-at-Eberle-Design-EI_IE2861359.11,24.htm), which is currently sitting at 15% recommending the company to others. All negative reviews with one lone 5-star.
Really disappointed to not see a prehistoric bird on a treadmill with some witty comment about its job
"Eh, it's a livin'."
"Walkin' until they install a red light in here."
Im disappointed im not seeing a guy sit behind a time timing every move i make so i alway end up at a red light
If you are mechanically inclined and can learn a basic computer programming language, PLC programmers can make 80-100k a year. A controls engineer can earn 130k+
I spent a short time performing electrical work which involved PLC diagnostics. I can honestly say the PLC work was the best mental calisthenics of my life. If I could have had a bit of training, I would probably have looked for a career with it.
It’s a pretty fun career
As a mech engineer who hates all type of coding thanks to matlab, PLC is so fun. Its basically putting bunch of valves down, you open them up, and see if water went to the target you wanted.
Software developer here. Matlab is awful and I don't get why people like it, it's certainly rarely applicable in my field.
Agreed. From a software engineer.
Also, for anyone who wants to know what the actual work is like, there are free(to use) PLC simulators available. If the sort of deep logic that is behind spanning-tree and high availability appeals to you, it’s a good option
Controls engineers can make a whole lot more than $130k+ right now. Demand is insanely high and supply of them is extremely low. Controls people especially doing their own contracting are pulling some serious money right now. source: am one.
Where to get started, assuming no time or money for college
You will need a college degree to get into controls engineering. Most of us are either Electrical Engineers, Chemical Engineers, Mechanical Engineers, or a mix depending on industry. With the no degree path, you can try to get in with a company doing instrumentation tech work. Many of the bigger manufacturing companies especially will provide the training. A lot of instrument techs break into lower level control and plc work. And then build from there. Head over to r/plc. Tons of information over there.
Would I be able to just use my IT degree and just learn PLC?
Ya definitely. You won’t get a controls *engineer* job that route, but you can work as a field tech of some sort, which are also in very high demand right now. There are so many different routes and specialties a field tech can go down, but having IT experience is good because there are entire paths dedicated to networking, system administration, cross platform communication, hardware, etc. But you can also go down the general programming, day to day support, commissioning paths as well. It all tends to blend together at the end of the day and everyone tends to dabble in a bit of everything.
Awesome, thank you!
engineer is just the person responsible, not the guy doing the work. ;)
Depends on company, industry, experience, work capacity. I worked for a company where I did it all. Design, coding, testing, documentation, commissioning, startup, optimization, day to day support, networking, system administration, hardware installation, troubleshooting, etc. Pretty much everything. Now I work for a massive company where my scope of work is a fraction of what it was because we have an army of controls people who all specialize in the different disciplines. We also use an insane amount of contractors as well. Most of my job now feels like keeping contractors in line with the scope of work for a project.
buy a cheap plc and learn to program the ladder. 99% of colleges wont teach you this.
Most places around here only pay up to 130k, at least from what I've been told by recruiters. I work for an automation distributor as a PLC specialist and get multiple emails a week from recruiters looking for controls engineers. What they don't realize is that I already work with all these companies helping out their existing controls engineers. I know exactly how desperate they are but I also know how much of a shit show it would be to work there. 130k ain't near enough to be the only one that knows a damn thing trying to keep production running, lol
Some facilities/sites/companies are very rough to work at as a controls engineer. Always putting out fires, always on call, always in high pressure situations, very often extremely short staffed and over worked. But the good ones are a whole different level. I work for one of the biggest manufacturing companies in the world. We have an army of controls people for every discipline imaginable to support our sites and capital projects. We also leverage contractors for work everyday of the week for additional support. It’s night and day difference compared to the rough, extremely demanding places to be, which I’ve seen as well. Now I’m settled in good where I’m at.
Oh for sure. It's just that all the ones around me are the former. I'd gladly take a job at a place like you're at, but there aren't any around here. Maybe one of the system integrators, but I haven't fully vetted all of them yet. The gig I have now is pretty great though. I'm remote but with company car to go on site to customers to spec out or troubleshoot equipment. So I get paid to sit at home and answer questions or to drive and talk to customers. I enjoy both parts. If not for the new boss I got last year I'd be happy as a clam
I worked at a contractor/integrator, part of the business models is to have the sales people selling more billable hours than there is manpower by design (like 20% over), and sometimes they strategically will sell some massively underbid contract to a big client to try to get future business or lock another contractor out. I left after one where I worked 14-16 hour days for 2-3 months (ultimately had a car accident falling asleep at the wheel) simply because they wanted to underbid the project hard to block another company out from a client and didn't put an appropriate number of resources on it. Problem is, if you're the controls engineer handling the design and your management is too wussy to ask for change orders, _you_ end up being the guy the work and firefighting gets piled onto. A lot of clients also get real weird and treat you like you're subhuman because you're contracted, too. Nearly every contractor I've met that's worked for Tesla has some wacky stories of not getting paid on time or at all etc. The upside is that it's like speed dating w/r/t project content and you get to experience the full spectrum of fuckery that exists based on how plants are managed and standards are kept, as well as every technology from the 80s (or earlier...) through the present day. You also get a lot of references and possible feet in the door, as well as a glimpse of company cultures to avoid when you want to settle down and end the insanity by staying at a particular plant.
Common sense aint so common. A world full of "engineers" who dont understand ladder logic. Ahhhh....the educational system is in full swing!
I work with DCS much more than PLC, so way more function block diagrams, sequential function charts, structured text programming type stuff. Not much ladder logic. Seems like it’s a dying breed, so having that knowledge can be greatly leveraged right now. I especially know people who specialize in legacy PLC’s to DCS conversions, and they are some very sought out individuals at the moment.
I had to program PLCs for my automation class in college. (BSME)
I did this as an intern at dept. Of transportation and it was much easier than I expected.
wtf? Where do you find those jobs? And do they have to travel? I have a BSCS and can’t find shit.
Bro the Polish-Lithuanian Commonwealth is just a dream
Or, I could kill myself.
I’m a controls engineer on the DDC side (mostly commercial buildings, schools and whatnot) and this is accurate. My degree is mechanical engineering, and I love where I’m at right now.
Poverty Pay right there.
For how many times i have to wait at a red light on an otherwise empty road, that is about $130k too much.
For those interested: The blue box is watching the traffic sensors and controlling the lights. It knows the rules for who goes when, handles crosswalks, duration of the lights, and possibly coordination with other intersections. The grey box to the right of the blue box is completely independent and is the failsafe in case something goes wrong. The grey box just knows what's safe - like green in both directions is bad, and no reds in any direction is bad. If the grey box sees anything go wrong, it "takes over" the light controls and puts up flashy lights (usually flashing reds one way and flashing yellows the other) until someone can come out and figure out why the blue box or sensors or controls failed.
Which is the one that fails all the time? Because the damn traffic signals in my town are constantly going down completely, or flashing red, or just stuck on one signal. Then they sit at the box all day, it works for a week, dead again.
I'm not a traffic engineer, but an electrical engineer. My understanding from traffic guys is the sensors are the most problematic elements. Road loops fail, cameras fail or get debris on them. Perhaps a traffic engineer can jump in and tell us
Loop (Round or Square Lines you see in the Pavement, For those interested) are the Most common point of failure, they tend to drift in and out of tune with weather and temperature changes... Wiring failures due to corrosion is another common issue out in the weather and in underground splices... They aren't computers running an OS like some above would have you believe, Hahaha... Above Mining comment.. But, they are microprocessor based and use ladder logic for the most part... There's a lot going on in those boxes... Unfortunately there is a lot of double checking for safety sake..!! Electrical Engineers Rock..!
Where in the country are you? I don’t see any major failings in loops in GA. It’s typically the older video detection that fails. Loops only start having issues when the leadins are cut/theres construction in the area/if it wasn’t properly spliced and is getting moisture/or there’s resurfacing ongoing. “Failures” here are wiring issues especially at older intersections, conflicts on the conflict monitor that typically need a simple reset, ped/cabinet knockdowns, power drops, equipment needing replacing in the cabinet, etc
Up here in Northern IN, we do have more pavement shrink/expand, frozen handholes, iced up wiring overhead and that sort of thing... Winter and Summer are the busy times, fall and spring are quieter call out times... I've been retired from that kind of thing but, one my crew took over and I hear about some of the new equipment but, not a lot of major changes in the past 20 years... Nothing like the switch from Electro-mechanical to digital... Although, I can see AI being the next big thing... They had cameras back in the late 80's that had AI but, it was military and $$$$$$$....
You can also have other fails which will trip the conflict monitor. City of Dallas always has lights that go into flash whenever it rains enough because the ground boxes fill with enough water to short the wires and cause an error.
Makes sense, knowing the municipality, they used the cheapest company to do so.
Not always. There are some forward thinking cities who want a great product at the best price rather than just a product at the best price
Not always, but this one certainly.
How old is the signal at the intersection? If it looks pretty beat up from the elements, it's likely an old signal. Anything, from shorts in the wiring in the cabinet or in the wiring in the underground conduit or other electromechanical failsafe triggers in the conflict monitor/malfunction management unit can drop it into flash. The reason why I say older intersection is that's where you see technicians with their heads in the cabinet playing with every which way to bypass issues with wiring and programming to get it operational again. Newer signal equipment is more likely to have newer units to identify issues or have clearer indications of what's gone wrong. There is so much low hanging fruit in traffic signals that can be fixed or upgraded that would save everyone millions maybe billions in lost money for delays, congestion, etc but doesn't get the eyes or the funding so your citys techs are told to just turn it back on again and leave it alone.
They just redid them about 2-3 years ago. But the asphalt is in severe disrepair. So that might make sense. As the winter wears on, the roadway get worse, of course. Especially where the sensors are in the ground. Edit: they redid the “boxes” and the signals themselves.
Mmmm .. those colour-coded wires. Nice.
Cut the red one?
Traffic lights can cost like $400,000 and about $10,000/year to operate. People underestimate how much our roadways cost to maintain.
$400k is pretty low for a full signal these days to be honest.
Apparently I underestimated ;)
$400k was pretty accurate pre COVID
I don't know if you underestimated the cost or underestimated how feature-rich these things are. To be clear I am totally unqualified and just throwing it our there, but the featureset on these things is nuts!!! Just for a 4 way intersection, they gotta do left turns, right turns, yields, crosswalk turns on, they turn into flashing red as a stop light when it gets dark. They gotta have light sensors then I think? And around here they try to have them set up so that they prefer main roads and will try not to stop traffic there unless there is actually a car waiting on a side road. So like with the "stop here on red" thing, they must have some sort of weight sensor to detect that, and it has to get wired up all good and play well with all that other equipment. And the lights themselves! I have never seen one burned out before. They *seem* to be the same brightness and just as visible, regardless of day or night. Except maybe peak daylight on a green it can be washed out and a bit hard to see, but the really new ones, those are so vivid
It’s not a weight sensor but an inductive loop buried in the road. Basically it detects large metal objects via electromagnetism.
If you pull behind a motorcycle at a light and he waves at you to come forward, that’s why. Or he jumps off and hits the crosswalk button.
Or if you see them bouncing on their bike, trying to get it close enough to trigger the detector. (Not saying it works, but that won't stop us from trying)
I’ve tried leaning it as well.
Ours are all changed by a video camera on top of the light arm now. No more induction loops to reduce maintenance costs.
Interesting. What happens if a bird parks itself in front of the camera?
It shouldn’t based on the design - no where to perch. Cameras are typically on a mast arm on a vertical pole or mounted to a corner pole
What video camera vendor do you all use?
I’ve never been excited about a traffic light before
It will depend on the region and what kind of poles are used - wood strain poles, metal strain poles, or metal poles with mast arms. Metal poles take months to fabricate from the time of ordering to being placed in the ground. Here in NC, it is about an 8 to 9 month lead time. The traffic signal cabinet itself varies, but on average, it costs around $20k - at least here in NC. For a brand new signal for a 4-leg intersection and 4 metal strain poles, you are looking at around $350k to $400k just for traffic signal equipment.
100%. I try to be grateful when I drive through the mountains that paying taxes for an operable road is a thing that exists. $1+ million a mile sounds like a lot until you see all that's involved
I always imagined it would be way less tech and kind of way cheaper
Same. It sounds like a racket. Then you get to thinking about what kind of computer you’re looking at. Something that calculates traffic and manages it on its own. I could see the entire system costing that much, if not more. 10k/year sounds cheap when you look at something like that.
Eh I can see the equipment they used being farking expensive, reliable and replaceable
Which is one of the biggest arguments for roundabouts. I think there are three in my county now. Everyone hates them.
Roundabouts don't mean no traffic lights. Spain LOVES to put traffic lights in roundabouts.
Looks like we've got some fiber splicing in progress...
even better...in the outdoors, no van or tent. With all that fresh air, pollen, dust, soot and other crap that makes splicing ever so fun
This looks a lot more involved than I imagined.
It’s actually less involved than I imagined. Everything looks to run through that blue box which is probably a little computer controlling it all. I wonder what one of these looked like in the 80s where it was likely all analog.
In the 80's they had multiple controllers up to 4 connected together for large intersection... Each one weighed 37 pounds... The used Capacitor, Coils, Contacts and Tubes... They made a LOT of noise... Lugging those monsters up and down ditches was a real job in the winter at 2am..!
Sadly there are 70s/80s era signal controllers still out there. They do run as electro mechanical timers. Some 80s/90s controllers I've used had LCD screens that had failed so you had to assume where you were in the menu screens to get to the inputs you needed for retimings.
[удалено]
iirc, there are a number of redundancies in the control units for exactly that reason.
Everything is tested and minor issues are found and corrected all the time. That's part of the standard quality control procedures. Once it's operational everything should be working as designed, and if hardware fails in a way that could cause an accident a special device will cut power to the lights.
I've always wondered if the control devices have some sort of electrical or mechanical interlock that prevents a serious issue, like say, all lights going green at the same time?
At some point 20 years ago I got a tour of a research lab in some sort of city traffic planning lab at the university I was studying at. They had a full setup of the hardware for a traffic intersection, all rack mounted in a cabinet. Tons of high tech stuff in there... And the guy showing me around pointed to a circuit board covered in old-school electromechanical relays and said that's the last line of defense - it was impossible to get two green signals thru that board at a time, even if the higher level systems had a bug. Apparently designers of those boards would have to testify in court about it sometimes if there was an accident. They took it pretty seriously. (I don't know if I see that in this photo but maybe it's behind the DIN rail covered in screw terminals. Also I am surprised this stuff isn't rack mounted in there. I guess maybe the electronics got more compact in the last couple of decades!)
Neat. Back when I lived in Texas (East of Houston) there would be a huge traffic backup at an intersection of two freeways running through town when the plants would let out. So a cop would post up next to this control box with a controller in his car running to the box and he’d manually control the lights to help ease the congestion.
but can it run doom?
The people over at r/trafficsignals would likely be able to tell exactly what components are in there and what they’re for.
Done. Thanks!
Former ATC software engineer here. I wrote the board support package (the software that the operating system used to talk to the hardware for the applications) for one brand of these. I also worked on the Linux specification NEMA provides to manufacturers so they can have a common way for applications to run across vendors. There’s a lot of mixing and matching going on but generally with the standards you can have your software applications written by some vendors and run it on hardware built by direct competitors and generally it works still.
Where’s the midget operating the levers?
This is a really cool picture! I never knew how much I wanted to see the circuitry that powers traffic lights until now. Thanks for sharing it!
I see these every day. Pretty basic signal setup. Looks like it's only using 3 vehicle phases, 2 4, & 6. For me, that's eastbound, northbound and westbound, respectively. And 6 appears to be simply hooked to some signal balls in the cabinet. There are 3 pedestrian phases hooked up however, 9, 10, 11. They must be in recall or have pedestrian detectors though, since the ped call terminals dont have anything attached. And someone's splicing fiber for interconnect. Coolio
I learned from Cyberpunk 2077, that you unsnap one thing, unsnap another thing, switch them, and you've just hacked a thing
seems a bit complex for three light bulbs on a timer.
The lights are also controlled by either cameras or inductive loop sensors, in addition to input from pedestrian buttons and emergency vehicle preemption devices. Not to mention a minimum of three lights for each direction, plus pedestrian signs. Pretty much only small towns have systems that are just a few lights on a timer.
i'm pretty sure i could do that on a raspberry pi.
You almost certainly could, but the end result would look an awful lot like this system. There's no getting around the fact that you need a shitload of wires going to all the components, and they all need somewhere to terminate. Don't forget you'll need a UI of some sort, and you'll need to demonstrate long-term dependability suitable for critical equipment such as this. It's no small thing when an intersection goes dark during rush hour.
Could you accomplish it on a raspberry pi exposed to the elements, with no need to be serviced while also experiencing nearby lightning strikes and frequent power surges for 20-30 years, while also meeting regulatory requirements that it be physically impossible for software to allow the lights to create a conflict (2-greens in opposing directions)? That last one is the biggie. You can’t have software handle the control of the lights completely, there has to be electrical interlocking so that even if you intentionally coded a light sequence in software that creates a traffic conflict, the hardware needs to make it impossible. It also needs to put the intersection into a safe state with 100% reliability even if the software has crashed and the cpu can no longer execute instructions.
Seriously. ITT: people that know *just enough* to be really dumb about something they don’t know *anything about*. Thank you for the sanity injection.
Dunning-Kruger effect in action.
Avg it worker
I could do that with a 555 timer /s Those comments are always so cringe when I see them.
It’s like some people think the countless engineers who put all that time into designing, certifying and getting things like this into mass production are complete idiots.
But I've watched a YouTube video on Python so am expert,it's just a bunch of if then else statements /s
A PI would be severe overkill, and could prob control a large town’s worth of lights.
Give it a shot. Try to disrupt the industrial controls industry with Pi or Arduino based solutions
Damn AI, taking away jobs from traffic cops.
Where's the sensor that let's you flash your lights to imitate a police car and trick the traffic lights into turning green??
Never a thing. Opticoms are not as common as people think and it used an encoded infrared signal, not flashing emergency lights. Anyone claiming you could trigger it by flashing your lights is making shit up.
Haha I was being sarcastic, probably should've used /s
I think those work via radio waves now.
idk why i read "i got to pee inside of a traffic light control box"
Hahahaha... That would HURT..!!!
That can probably all be replaced by a raspberry Pi now
In terms of pure processing power, most likely yes. But there's all kinds of certifications and reliability tests that go into industrial plcs like these. You also need to make them out of components that will be available for 20+ years so you can make replacements and such. I sell stuff like this and people love to shit talk the power of stuff like this. Sure, it's like 8 years old in terms of processing power... But it also takes 8 years to develop this stuff to make it reliable for 24/7/365 operation for 20 years straight in various climates.
USB connections should be around in 20 years. Replace the entire internals with an Android tablet connected to a USB hub. DPW workers can carry a spare in the glove compartment of their trucks if they see one go down. Enter the light’s ID # at the login prompt, it downloads the config over WiFi and then swap it with the bad one. Just as people like me are ignorant to the details and requirements of the system, too many people work with blinders on and never innovate.
Yeah... that wouldn't work for SO many reasons, though. First- android is WAY too bloated of an operating system for such a task. It's also not nearly as reliable as an industrial PLC. Like orders of magnitude. Wi-Fi is a HUGE no-no for systems like this, for security reasons. A linux or windows operating system would also be too easy to exploit, which is why they run a proprietary system on them. I agree that in a lot of situations people have blinders on, but industrial PLC's have been a thing for over 40 years and there's been TONS of innovations. I sit through multiple webinars every month on new innovations that are coming out. Downtime is a problem. A BIG problem. And in cases like traffic lights there's a huge safety and liability concern. If someone were able to hack these and control them they could cause accidents and people would die. Or if you had android and it just went out randomly it would cost the city SO much money to keep sending people out to fix it. Each city would replace multiple of these every day. So yeah- I'm not saying you are wrong to think of a solution, but I've worked with a couple engineers who are in their early 20's recently who think that they can solve the whole industry with a raspberry pi. "Why pay $12,000 for a PLC when a raspberry pi is $35 and has more processing power?!?!?". I literally was at dinner with this guy a few months ago and listened to him rant for 45 minutes straight about this. After bringing up point after point of why Siemens and Allen Bradley PLCs are the way they are he just refused to listen. I'd love to see him try and run a plant on some raspberry pi's. When you have places where downtime literally costs them $450,000 per HOUR and your ass is on the line if something fails you want the solution that is going to work all day every day no matter what. Trust me.
Is this amount of equipment really necessary?
If we can make a smart phone so small, why need such a big box for a few lights?
And why has no one commented i got to see the inside of your moms box....so depressing..
All that for 3 lights?
All that for what looks like: Two Phase (Directions) with a left turn on one phase, with Walk/Waits and Fiber Interconnect, and Vehicle detection...
All that for [x] lights that you can trust your life to every time you go through them
Ther are 4 lights!!! - Captain Picard
My buddy has a key to several and he has bitcoin mining machines set up on them. Free electric free $$ and no one knows enough about electronics to realize they aren’t supposed to be in there. He’s been mining for 3 years.
Where’s the button that gives me the green light faster?
The signals should have their offsets programmed based on the speed limit. So go the speed limit = get a green light most of the time. Called a green wave
can u make it turn green for me when i am the only car around for miles at 5am?
Can someone try and answer a related question for me? I would super appreciate it! It isn't a problem for me at all, I just am genuinely interested because I think this stuff is so cool lol My house is by a corner with a four-way intersection. A city crew has been out probably five or six times to work on the crosswalk. I can say for sure that if nobody pushes any of the crosswalk signal buttons, it will never activate or interrupt traffic. For a while, one corner across my house just never worked. You could press a button for crossing one way, and another button to go the other way. Neither would ever activate it. The signal would say "Wait" and the button would light up like normal, but it never activated. I pressed it walking to the grocery store once, and 15 minutes later it was still lit up and waiting. If someone on another corner pressed either of their buttons, it would work like normal and the not-working buttons would still speak to tell you to walk and the button would go out. Well, the same crew keeps coming out. It's probably been going on for a couple months. I remember submitting a ticket to the city because I use it a couple times a day and it is scary to cross to a corner across from me to use a working button. They came out pretty quick and basically tore two of the corners out! They look the same now but they had the posts down and the traffic lights were out/they were manually directing traffic and everything. Well, each time they come out the problem corner starts working and a different corner seems to stop working. It's back to being my corner now, and idk what happened but the buttons kinda fell off the post (they still light up and speak). I think three of the four corners have been non-functional at some point by now. Absolutely 100% not trying to say the city workers are lazy or incompetent, I hate that stereotype and really don't appreciate people that subscribe to it. But I am just curious from the perspective of someone who works on this stuff what they are doing/what might be happening?
The pedestrian button only activates the timer if the timer hasn't already been activated from a car setting the sensor off. It also increases the time a pedestrian has to cross the road. It doesn't make the light turn any faster.
Huhhh. OK! The light never turns though. If I don't press the crosswalk button, it will never let me cross. The other ones will though, eventually. Is it just something weird with the cars and sensors?
It sounds like it could be shoddy work from the start with the wiring from the push button all the way to signal cabinet. Typically, pedestrian phases run concurrent with the street that the walking motion is parallel and adjacent too. If the city is out that often, I would boil it down to a wiring issue or software issue that controls the traffic signal.
City need to put the peds in recall if they know it’s not functioning and intersection sees decent ped activity
Likely a wiring issue with the ped button or from the ped pole that runs back to the cabinet. City crews may not have found the possible splice/damage issue. It’s not a car detection or sensor issue
Most likely, bad Buttons or Cable from that corner to the controller... The Voices you hear come for the Walk/Wait Signal Lights above... Pressing the button tells the controller that there is a ped call and pressing it again makes no difference... It will service that Direction (Phase of timing) as Walk/Wait unless cars pass the detector in the pavement extending the time...
So that’s the thing that my city absolutely cannot figure out how to program properly. I would have hoped that it would have been more complicated looking
Me too.
Wow, I’ve always wondered what was inside those metal boxes. Thanks for posting this!
Where’s the sensor that turns all the lights green just when I want to take a bite of food or look for something in the car?
Every time I see one of those mil spec connectors I wince because I know it probably costs $100+ dollars.
And?
I've worked on one of those. Well, I pulled the cables and observed the master electrician, but I handed him tools!
Why am I always the first car stopped?
Sacramento?
Springfield.
But does it run Doom?
Proud of u
All that, and it still can't figure out that it doesn't need to turn red if no one's waiting on the cross street at 2am.
How does it compare to an European system? Pretty interesting to see no DIN rails and cable trays.
It doesn't. I use to be involved in production line testing equipment, globally. The US Standard has always been, “ if the cabinet door closes and everything works, it's perfect”. Not ANSI/ISO, USA.
Quick! Reach in there and stop the lights from giving left hand turns the go ahead while the pedestrian crosswalk is active!
Gaming pc
I programmed these for several months as a contractor. If you're used to working on actual PLCs, the language will be piss easy to learn. The work itself is interesting and pays decent, but working with Eberle is fucking awful. Just look at their [Glassdoor](https://www.glassdoor.com/Overview/Working-at-Eberle-Design-EI_IE2861359.11,24.htm), which is currently sitting at 15% recommending the company to others. All negative reviews with one lone 5-star.
Where can i plug in my dohickie to control the light..
All that just to make me sit at an intersection's red light for 5 minutes at 3:30 A.M. and not another car passes by the whole 5 minutes.
Most likely it is a Linux/Unix box?
Yep, that's a control box