Communication with Point of sale terminal (POS)

[abfer]

I don't know how pos terminals work. But i need to use a pos terminal in a project. Basically the microcontroller based system will tell the pos terminal the amount to charge the credit card of the customer and the the pos terminal will return the information of payment received or not. Is this possible? Is current devices allows such communication with an outer device like a microcontroller over serial port etc? Thanks.

 

[MacGyverS2000]

Is this for school?

Dan - Owner

http://www.Hi-TecDesigns.com

 

[Skogsgurra]

Or is it to read other people's PIN?

Gunnar Englund

http://www.gke.org

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Half full - Half empty? I don't mind. It's what in it that counts.

 

[abfer]

Is there anything here that is related to steal other people's identity information? How other similar systems work? Think of a gas station. Think there's 2 systems. One is pos terminal and the other is related to other things like gas pump, gas meter etc. The customer comes in, enters the amount that he/she will purchase to gas system, put his/her card into pos device, the system sends pos device the amount the customer enters, pos system checks if the amount is available and charges the card and send confirmation info to the gas system and gas system supplies the gas to the customer after it receives confirmation from pos terminal. Is this possible or is there anything that is illegal?

 

[Skogsgurra]

I can't say. But if all is OK and perfectly legal, then the supplier of the POS terminal - or the gas pump supplier should be happy to supply you with the information you need.

Many years ago, it used to be a simple RS232 link with a simple ASCII protocol with RTS/CTS handshaking. Could be that this is still used. Hook up a line sniffer and see what it looks like.

Gunnar Englund

http://www.gke.org

--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.

 

[abfer]

I'll also talk with bank, pos device manufacturer and other people. I'm in research now. May be an experienced people can classfiy and clarify the situation and help me to go the right direction. There is nothing illegal with my request. There are probably billions of applications which require much more info than my request. How can you trust them? I believe you don't use credit card at all if you're this sceptical.

 

[Skogsgurra]

Yes, I do. I am not living in a hut in the mountains.

I think I have given you some valuable information. RS232, ASCII, RTS/CTS handshaking. Perhaps not in all modern terminals. But, if you want information for a specific terminal - you have to tell us what terminal you are talking about, and what application.

Gunnar Englund

http://www.gke.org

--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.

 

[MacGyverS2000]

What kind of project do you need to use a POS terminal with that you also need access to the information it transmits? In a typical POS transaction, the transaction server returns a message detailing the status of the request, which includes if it was successful (and if it wasn't, the reason behind the denial).

You need to understand the transaction itself (details can be obtained from the obvious sources) before trying to create a secondary terminal, as you may find all is not what it seems...

Dan - Owner

http://www.Hi-TecDesigns.com

 

[abfer]

The project is like my gas station example. Basically there's a service that customer purchases and make the payment via credit card. I don't want to go into details of payment as possible as i can. The other parts are complex enough and i don't want to spend much time on payment issue but it is required, so i will and must go as deep as it needs. As i said before, if the pos terminal can accept the charge amount(from our device or system) and returns the payment status (success or not) that is enough for me. As i've learned, banks can supply software library (as a DLL file) and pos terminal. But since the system will not include computer (as long as it is not absolutely necessary) we cannot use it. I don't want to dive into the communication between pos terminal and payment server (bank etc). I only want from Pos terminal to give me a report over something(serial, usb or ethernet) and accept the amount of money to charge the credit card. That's all. And i believe this should be available at least in some devices. I don't know anything about the devices, manufacturers, protocols and current applications. But i'm searching and thinking that something like this should be available since there are lots of applications similar to this.

 

[IRstuff]

I don't get what you're trying to do. If the POS is intended to communicate with both a central system as well as a remote system, then the interfaces are not only well-understood, but there are already existing software that run those interfaces. So, why not simply buy another copy of the existing hardware and software and only add a relay box for the duplicate hardware?

TTFN

FAQ731-376
Chinese prisoner wins Nobel Peace Prize

 

[VEBill]

Usually one refers to the applicable manuals to find such info.

 

[MacGyverS2000]

I don't know anything about the devices, manufacturers, protocols and current applications.

How do you intend to interface with products you know nothing about the operation of?

Dan - Owner

http://www.Hi-TecDesigns.com