Abbreviation for optical fiber, conductive.
Note: OFC is the designation given by the National Fire Protection Association (NFPA) to interior fiber-optic cables which contain at least one electrically conductive, non-current-carrying component, such as a metallic strength member or vapor barrier, and which are not certified for use in plenum or riser applications. [After FAA]

Abbreviation for optical fiber, conductive, plenum.
Note: OFCP is the designation given by the National Fire Protection Association (NFPA) to interior fiber-optic cables which contain at least one electrically conductive, non-current-carrying component such as a metallic strength member or vapor barrier, and which are certified for use in plenum applications. [After FAA]

Abbreviation for optical fiber, conductive, riser.
Note: OFCR is the designation given by the National Fire Protection Association (NFPA) to interior fiber-optic cables which contain at least one electrically conductive, non-current-carrying component such as a metallic strength member or vapor barrier, and which are certified for use in riser applications. [After FAA]

1. In computer technology, the state or condition of a device or equipment that is not under the direct control of another device.
2. In computer technology, the status of a device that is disconnected from service.

An optical system in which the optical axis of the aperture is not coincident with the mechanical center of the aperture.
Note: The principal applications of off-axis optical systems are to avoid obstruction of the primary aperture by secondary optical elements, instrument packages, or sensors, and to provide ready access to instrument packages or sensors at the focus. The engineering… (Read More →)

1. In telephony, the condition that exists when an operational telephone instrument or other user instrument is in use, i.e., during dialing or communicating.
Note: Off-hook originally referred to the condition that prevailed when the separate earpiece, i.e., receiver, was removed from its switchhook, which extended from a vertical post that also supported the microphone, and which connected the instrument… (Read More →)

Synonym hotline.

In telephony, of a circuit, a signal indicating seizure, request for service, or a busy condition.

1. Pertaining to the operation of a functional unit when not under the direct control of the system with which it is associated.
Note 1: Off-line units are not available for immediate use on demand by the system.
Note 2: Off-line units may be independently operated.
2. Pertaining to equipment that is disconnected from a system, is not in operation,… (Read More →)

A particular form of authentication information binding an entity to a cryptographic key, certified by a trusted authority, which may be used for authentication without directly interacting with the authority [10181-2].