external lock signal

例句：

1. 1. The device has anexternal locking mechanism that prevents unauthorized access.
   该设备具有外部锁定机制，防止未经授权的访问。
2. 2. Thesecurity system uses an external locking signalto ensure the door is closed and secure.
   安全系统使用外部锁定信号来确保门已关闭并安全。
3. 3. Themanufacturer provides a manual forsetting up the external lockingsignal.
   制造商提供了一本手册，用于设置外部锁定信号。