AT-MR420TR and AT-MR820TR Installation Guide
41
SQE TEST—Commonly referred to as Heartbeat, is a special 802.3 signal sent
by the MAU to the DTE to test the collision detection function. Some DTE want
SQE and others do not. Repeaters do not want the SQE Test.
STRAIGHT-THROUGH—A type of wiring connection where the pins of one
connector connect to the same pins of another connector. For example, pin 1 of
one connector connects to pin 1 of another connector.
THICK ETHERNET—See 10Base5
THIN ETHERNET—See 10Base2
TRUNK CABLE—The coaxial cable used to distribute signals over long
distances throughout a cable system.
UNSHIELDED TWISTED PAIR (UTP)—A cable used in 10Base-T wiring
that consists of at least two twisted pairs of 22 to 26 AWG wire. The pairs
should have at least 3 twists per foot and have an impedance of 100
Ω
. Level 3,
Level 4 and Level 5 UTP cables fit these criteria.
MRx20TR(STP/UTP)_BookA Page 41 Thursday, April 3, 1997 5:24 PM
