As per my knowledge there isn't any standard integration for DBM cash desk direclty with credit / debit card machine, however you can build a custom interface.
The standard credit card functionality can be used here by implementing the BADI "/DBM/BADI_TILL"
One of my previous experience we added an additional push button on the cash desk screen to do similar kind of requirement & intern call the BADI "/DBM/BADI_TILL"
You will have to define various payment types "Credit card", "Debit card", Cash etc..
Regards,
Sachin Balmiki