FC — round type with threaded coupling; commonly used on optical transceivers and similar equipment. ST — bayonet-lock round type; commonly used on termination boxes. SC — bayonet-lock square type; commonly used on fiber media converters. PC — micro-spherical polished (physical contact). APC — angled at 8 degrees with micro-spherical polishing. Fiber optic patch cord connector guide: The connector on a fiber optic patch cord is a key consideration when purchasing one. Understanding what the various fiber optic patch cord connectors mean helps users find the product they need more quickly.

① FC-type fiber optic patch cord: reinforced externally with a metal sleeve and fastened with a screw thread. Typically used on the ODF side (most common on patch panels).

② SC-type fiber optic patch cord: the connector for linking GBIC optical modules. Its housing is rectangular and it is fastened with a push-pull latch mechanism, requiring no rotation. (Most common on routers and switches.)

③ ST-type fiber optic patch cord: commonly used on optical distribution frames. Its housing is round and it is fastened with a screw thread. (For 10Base-F connections, the connector is usually ST type. Commonly used on optical distribution frames.)

④ LC-type fiber optic patch cord: the connector for linking SFP modules. It is made with an easy-to-operate modular jack (RJ) latch mechanism. (Commonly used on routers.)

⑤ MT-RJ-type fiber optic patch cord: an integrated square transmit-and-receive fiber connector, with dual fibers for transmit and receive in a single head. ST and SC connectors are commonly used in general networks. The ST connector, once inserted, is secured by a bayonet mount after a half turn; its drawback is that it breaks easily. The SC connector plugs and unplugs directly, which is very convenient, but its drawback is that it can come loose easily. The FC connector is generally used in telecom networks and is screwed onto the adapter with a nut; its advantages are that it is secure and dust-resistant, while its drawback is slightly longer installation time. The MTRJ-type fiber optic patch cord consists of two high-precision molded plastic connectors and an optical cable. The connector’s external parts are precision plastic components and include a push-pull latching mechanism. It is suitable for indoor applications in telecom and data network systems.

Optical modules: generally all support hot swapping. GBIC uses mostly SC or ST type fiber interfaces; SFP, i.e., small form-factor pluggable GBIC, uses LC type fiber.