pls am tryin to write a software that interface with a cash register and gett data from it,i need help

WHat technology(ies) are you working with? What information do you have on the current cash register system?

i am using .net and have not really decided on the hardware i.e the cash register to use cause am not sure which to use

Have you even started on application design? What do you want your Cash Register app to allow user to do? How do you plan to get input from the user? Where/how do you want to store the data? I mean you have to do your research and then come back with information that we can help with. Just saying you want to write a cash register program for a non-existent cash register does not help us much. If you want to be a programmer, at least be willing to act like one and better communicate your problem so we can be on the same page.

the app is for a hotel i want to be able to reconcile sales and inventory at the resturant with the module that manages the accounts of the whole system.so want i want is a way to logg sales records i.e quantity ,items and value so that the module can generate cash reports and inventory reports .

i was hoping of using he serial port of a cash register ,am not sure if i can use AT commands with a cash register.