E&M Concrete Interface
The concrete E&M interface is an RJ-48 adapter that connects to PBX block lines,
which are classified as either two-wire or four-wire.
Two or four affairs are acclimated for signaling, and the actual two pairs of affairs serve as
the audio path. This refers to whether the audio aisle is abounding bifold on one brace of wires
(two-wire) or on two pairs of affairs (four-wire).
Note Two-wire and four-wire accredit to the articulation wires. A affiliation ability be alleged a
four-wire E&M ambit although it absolutely has six to eight concrete wires.