This function is allow user to perform synchronization with POS backend database. Note: If there are any changes made in POS backend, synchronization must be done in order to reflect the changes to POS frontend. System will automatically synchronize every 15 minutes, if user have make some changes done in POS backend, and she/he need it to reflect to POS frontend immediately, user can use this function. 该功能允许用户与 POS 后台数据库同步。 注意：如果 POS 后台有任何更改，必须进行同步才能将更改反映到 POS 前端。 系统将每 15 分钟自动同步一次，如果用户在 POS 后台做了一些更改，需要立即反映到 POS 前端，可以使用此功能。 Free Try +60127479966 ( Mr Yu) https://wa.me/60127479966 Support Hotline: 1700819966 Our Facebook : https://www.facebook.com/uksoftware2u