Yes, indeed you need a Magento connector to help sync that data with your backend inventory and POS systems. We actually provide a solution that would help you achieve this.
Using our nChannel connector for Magento you can quickly and easily integrate and connect Magento to a variety of POS, ERP and accounting systems. Once downloaded, our Magento connector starts copying your customer, item, sales and supplier data to the nchannel platform.
Let me know if you have any questions.