Sending total price to cash register

Hi all.
I had an interesting answer to one similar question here:
Now I can be more specific. Supposing the cash register is usb connected a computer which acts as server, how can I make the cash register receive the total amount of the orders of a customer? What is the logic?
My idea is to deploy a web app which will be used  from clients to place orders. To print orders I can place a litener in the server to print them when they are inserted in the database, but how manage the cash recorder interface? Don't need (for the moment) to manage the transaction: just need to send the total to the till.
Iread that I'd need some php function to interface to Windows and execute DOS ESC Code Sequences, but I have no idea about what this means...
Thank you in advance.
LVL 32
Marco GasiFreelancerAsked:
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Instead of having the client device communicate directly with both the printer and the till, it would seem better to have the client device communicate only with a server, and then the server should communicate with both the printer and the till.  This way, communication could happen between the client and the server in a RESTful way or any other way that you are comfortable with.

                     Client Device
                            ↓ (REST)
                        |     ↓  (Triggered Response)
                        |     Printer
                        ↓ (Protocol of Till)

DOS Escape Code Sequences are archaic.  They are limited in their capabilities and prone to injections.  You may find this Wikipedia article helpful:

You will need to follow the protocol of the till, as defined by its documentation.   If that requires the use of  DOS ESC Code Sequences then you will have to rely on documentation associated with the till.

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
Marco GasiFreelancerAuthor Commented:
Lol, great avatar! Thanks for your reply, skij Yes, that was my idea: communicate with the server and let the server do the rest. I don't think printing could be a problem, but what's puzzling me is the till. I have to choose a couple of tills to suggest to the client (it's a startup) and I don't know where I can start from, what info I have to look for and so on... And I 'd really appreciate any guidance about RESTful or any method suitable to do the task. Until now I just did websites a small cms (to manage  websites made by me) and a couple of more complex web apps. But nothing interacting with hardware which were not a normal usb printer...
Some more technical/practical suggestion? :-)
You will need to do your own research to select a cash register till.  Do a web search for "programmable cash register" to start with.

I have attached documentation for the Sam4s ER-655-II Cash Register,
On page 94 it discusses: "PC Communication" and page 111 discusses its two serial ports.
Marco GasiFreelancerAuthor Commented:
Thank you so mutch. I'll do the web search. And thanks for the manual. I leave the question open for sometime to see if some other expert has useful ideas :-)
Marco GasiFreelancerAuthor Commented:
Thank you for your help. Cheers
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today

From novice to tech pro — start learning today.