I get this question asked to me a lot: “Just what exactly are interfaces?” Now, before I explain, let me preface by mentioning one thing I love about working at L-Tron. Every order, big or small, gets handled by its own sales rep from start to finish. We love to get it right the first time and we do our best to be helpful and informative. So, in an effort to address the previous question that I encounter on an almost weekly basis, I would like to do a quick rundown on what interfaces are in relation to the POS realm, and what they mean to you…because while the product you have been using for twenty years may have fulfilled your needs with your old system, it doesn’t mean that the brand new product will.

What are interfaces?
To put it shortly, and in a way that all of my tech geek buddies will scream at me about, interfaces are how your product ‘talks’ to the computer. The five most commonly found interfaces in the POS realm are in order of most-to-least popular: USB, Ethernet, Serial, PS/2, and Parallel. If you have no idea what any of these are, please read on, because I am trying to save you money and a lot of headache for both yourself and your sales representative.
Why does the type of interface matter?
Simply put, because if you buy a Parallel interface product and your computer doesn’t have a parallel port your product will effectively become a high-priced paper weight. Ditto for Serial, USB, and Ethernet.
Wait, what are ports?
What your product plugs into. They are all distinct from one another and have distinguishing characteristics.
Okay smart guy, how can you tell them apart?
Come with me, and you’ll be in a world of pure imagination…or at least be able to know what type of interface you’re using.
USB Interface
This is the most common, and is found all over the world today. In the photo below, you can see a common USB interface found on the front of my computer. Not only will you find USB on your receipt printers and barcode scanners, but you can also find them on things like smartphones and even some refrigerators today.

A simple USB port
A simple USB port

Serial Interface
There are a couple different kinds, usually in the male or female versions shown in the photo below.
Male and Female Serial Interfaces
Male and Female Serial Interfaces

PS/2 Interface
You will generally find these for things like barcode scanners, keyboards, and mice. Purple is for keyboard interfaces (typically denoted as KBW), green is for mice interfaces.
The common PS2 Interfaces
The common PS2 Interfaces

Parallel Interface
The parallel interface is largely falling out of favor today, and is usually found as a legacy (read: old) interface.
The old dinosaur, the Parallel Interface
The old dinosaur, the Parallel Interface

Ethernet Interface
I’ve commonly heard this interface referred to as “where the internet plugs in” from my Mother. It is quickly gaining popularity, especially for printers, as you can network many computers to a single printer.
The new kid in town, the Ethernet Interface
The new kid in town, the Ethernet Interface

Okay, that’s all fine and dandy now that I know what these look like. Where do I go from here?
Off, into the world, a little better educated, and able to purchase your products with confidence in this fast-moving world! In all seriousness, I love the aspect of my job where I talk to customers and explain to them what their best fits are. If you have any more questions, please feel free to ask. Keep in mind that the printer that worked twenty years ago probably isn’t going to work on the computer you bought two days ago!

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