There is an option to set quantity by using “set quantity” button on the mpos but in retail sector, every operational effort is not acceptable and it takes time to use all the time the “set quantity” button. When you try to set quantity by using the numpad, enter in the quantity and right after click the "*" button, and then scan the barcode with opos, the product’s quantity is being added as just 1 whatever you enter in to the numpad as quantity. In addition, when I enter in the barcode on the numpad manually, it works. But with opos scan, it doesn't work.

You should be able to set a quantity, scan a barcode and the quantity should stay at the entered quantity and not reset to 1.