Off-line

In telecommunication, the term off-line has the following meanings:

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, and usually has its main power source disconnected or turned off.

Source: from Federal Standard 1037C and from MIL-STD-188