How are prohibitive vehicle bars programmed?

Architecture

Hello

I am a web developer and after some years of working professionally, I finally have an idea of how the web and restful APIs work and I would like to explore other areas, just for the sake of knowing.

So yesterday a visited a very well known furniture store with my car and I parked my car on the underground parking.

When you enter and leave, you have to press a button to talk to security in order for them to open the bars from the operating room.

Then process is like that: You press a button, you talk to the security, the security decides whether to open the bars or not, if the security agrees he has to press the button.

Now what in wondering about is how the bar works. Is the mechanism connected to the network and has a server running waiting for requests?

Is there any big logic circuit with XOR, NOR, AND, OR, etc. gates to make the button work?

Does the mechanism needs some kind of cable which will be directly connected with the button?

What programming language would it need for programming it?

What if the bars were fully automatic, scan a QR code, check the receipt to see if the customer paid in order for him to leave ? Is the mechanism a server?

I believe all the above are possible and each scenario depends on the needs. But still I would like to ask to understand more

in AskProgrammingby leonheartx1988

56%

14d

GreenWoodDragon

14d

At the simplest it is a mechanism with an open/close switch wired to the security office/hut.

Automatic versions would have an inductive loop in the ground which would connect to a switch box. Modern ones probably have camera connected to software, enhanced by ANPR in some places.

Serpardum

14d

Could be any number of things, being an engineering problem. There are 150 different ways to do anything.

Maybe it's an underground cable connected from a button the guard pushes to a mechanism in the bar itself. Since the bar needs power, at the least, and since a cable already has to be run, this is generally the most cost-effective way and most secure.

As the distance from the guard to the bar increases it becomes more and more cost effective to transmit the signal some other way rather than running a cable. Perhaps a simple radio transmission such as used on a garage door. Perhaps a wireless router with a relay and circuitry, etc.

Since there are many ways to do it, there is no real way of knowing how it is done at any specific location without getting more details. Perhaps the bar mechanism has a name plate from the manufacturer, then go to the manufacturer and look how they do it.

If I wanted to know for a specific location, I would get all the information I could non intrusively about the bar itself.

Or, you can just use social engineering and ask a guard who works there if they know. But all they'll probably know is they hit a button and the bar lifts. "Magic".

Cerulean_IsFancyBlue

14d

Yeah, it’s not only an engineering problem but it’s a problem that’s been around for many decades, meaning that it’s been solved multiple times with different technology available.

khedoros

14d

Could be completely electromechanical. Could be structured any number of different ways, assuming it uses some variety of computerized hardware.

What programming language would it need for programming it?

Anything from assembly for some 4-bit microcontroller that doesn't even have a C compiler up to some over-engineered thing with half-a-dozen different web-oriented languages, micro-services running in containers, all to implement a fancy web gui, stream video from various security cameras, access a parking database, integrate with payment processing systems, etc.

What if the bars were fully automatic, scan a QR code, check the receipt to see if the customer paid in order for him to leave ? Is the mechanism a server?

Like the mechanism of tracking entry, egress, payment, etc? Sure, that's reasonable. Running a database, and acting as the centralized agent for external hardware like the gates, payment terminals, etc.