The Yokogawa YNT511D Optical BUS Repeater Rack is a device used in industrial automation systems to extend the reach of a communication network.

• Function: Extends the distance over which data can be transmitted on an optical fiber network. This is important in industrial settings where equipment might be spread out over a large area.
• Optical BUS: Refers to the fact that it uses fiber optic cables for communication. Fiber optic cables are less susceptible to electromagnetic interference compared to traditional copper cables, making them suitable for industrial environments.
• Repeater Rack: Indicates it houses multiple repeaters. A repeater receives a weakened signal, amplifies it, and retransmits it, effectively extending the range of the signal.