The most common Android cash register is a serial port, even if it is a USB port, it is not a real serial port.
1.Ticket printer - the external ticket printer is a USB port, and it is sure to lose the order - the built-in ticket printer is actually a USB port, the same problem
2.The kitchen printer uses the network port, the result is that it will lose the single
3.The glue printer uses USB or network port. The result is that the device will not be found or the ticket will be lost.
4.Communication scale: USB interface, the result is that the data will not be read.
5. The small USB interface of the cash box is deceptive. First of all, this interface The cash box is not standard, it is difficult to find, and it is not good. The second kind of interface is mostly 8.5V. It can't be opened often, and it is all small money box.