系统对所以账户的数据库记录，实现对系统账户的管理，包括账户信息管理和权限设置。操作系统登陆、退出、换班与操作锁定等权限验证保护；断电自动保护最大限度防止意外及恶意非法操作。-System database records, it is the account management system account, including account management and permissions settings. Landing permission to exit shift operation lock to verify protection　automatic power protection to maximize the illegal operation to prevent accidental and malicious operating system.