GLOSSARY

Enterprise Integration and Communications Systems

- T -

TAGS
Technical Assistance Groups. (See IEEE 802).

Task
A recognized action or set of actions comprising a specific part of the operations of a functional entity in fulfilling the established manufacturing policy of the company. It is the lowest level of functional decomposition of an enterprise that corresponds to the function of a single person or machine at a point in time. A task corresponds to an information transformation in the usual definition of a CIM system.

TC
Technical Committee.

Time-Phased Decomposition
Involves reducing the complexity of a system by decomposing the solution into a number of hierarchically arranged modules. Each level of the hierarchy represents: A. A shift in the time domain (lower-level layers are closer to real-time). B. A corresponding narrowing of the "scope-of-control" in lower levels. C. Each level provides planning (control) input to lower layers and accepts process status from lower layers. E.G.:

Token Bus
An access procedure where the right to transmit is passed from device to device via a logical ring on a physical bus. (See IEEE 802.4). This standard saw little practical implementation.

Token Ring
An access procedure where the right to transmit is passed from device to device via a physical ring. (See IEEE 802.5). This was widely used by IBM for many years, since it offered more reliable timing of message delivery. However, it has largely been supplanted by the more popular Ethernet standard.

Token Passing
A LAN-access technique in which participating stations circulate a special bit pattern (the token) that grants network access to each station in sequence; it is often used in ring topology networks, which have a single cable or dual cables strung from station to station in the shape of a ring. Bus topologies utilize a single strand of cable to which stations are attached. Tokens are special bit patterns or packets that circulate from node to node when there is no network traffic. Possession of the token gives a node exclusive outgoing access to the network, thus avoiding conflict with other nodes that wish to transmit.

TOP
Technical and Office Protocol. A development of the CSMA/CD (Carrier Sense Multiple Access with Collision Detection) protocol (also IEEE 802.3) under the auspices of Boeing Computer Services for office and laboratory automation use. This has been combined with MAP and further development will be under the auspices of the MAP/TOP Users Group.

Topology
The surface structure or arrangement of parts of any object.

TQC (Total Quality Control)
A theory of quality whereby the maker of the part has the responsibility for the quality of that part.

Traceability Identification
An identifier used with a part number to denote each unit (a lot has a quantity of several units) in a family of similar items. It provides for affectivity identification of design changes. [SAMA].

TTP
Telephone Twisted Pair. Also known as UTP - Unshielded Twisted Pair. A network medium that uses existing (4 conductor unshielded twisted pair) telephone wiring. TTP can be used for standard IEEE 802.3 Ethernet up to a speed of 10 Mbps, however 8 conductor "Category 5" Unshielded Twisted Pair (UTP) wiring is necessary to support 100 Mbps Ethernet.