I see places like whole food are using windows desktop application(maybe c# or java, I don't know) and verifone emv device to accept customer payment.
Our company wants to do the same thing. The problem is we don't know how Verifone device connects to the desktop application. Does anyone have clues how the verifone device talk to Desktop POS application?
Lets split it into two entities, (1)The POS where you enter the amount and what prints the receipt.(2)the terminal, where the card transaction happens.
Check with VeriFone on SDK that you can use to integrate your POS with the terminal. Once integration is over (1)once payable amount is ready at POS, sent the amount to terminal using the API provided by VeriFone so that you do not have to manually enter the amount (2)Once the amount is received by terminal, it can ask for the card and continue like usual and finally update the status back to POS. (3) the POS based on the result provided by the terminal decides whether the transaction is successful or not.
Normally POS connects to terminal, not the other way around.