(A chain of convenience stores hopes to manage and operate doors more effectively, so it needs to monitor cashier transactions, maintain in-store property to prevent theft, and develop a set of education and training programs that are effective for new employees. In view of the loss of cash and items in the store, it is necessary to introduce a POS device that contacts the DVR to monitor the cashier status in the store. At the same time, due to the high turnover rate of cashier personnel, the store hopes to achieve the purpose of practice by letting new employees watch DVD videos... This article is published by kvm forum: kvm/collection!)