Cabletron Systems 1800 E&M Signa l ing Types

C-14 SmartSwi tch 18 00 4.0 U ser Gui de, Rev 01
Figure C-8 E&M Con necti o ns
E&M Signa l ing Types
The Smar tSwit c h 1800 su pport s five E& M signa ling st andard s (Type s I throug h V)
for PBX tie line inter face s. These c onvent ions, as def ined by AT& T s pecifi cations , are
descri be d below .
With each signaling type, the PBX supplies one signal, known as the "M" signal (for
Mouth), and accepts one signal, known as the "E" signal (for Ear ). Conver sely, the tie
line equipment (e.g. , the SmartS witch 1 800) accepts the "M" signal f rom the PB X and
provides the "E" signal to the PBX. The "M" signal accep ted by the tie line eq uipment
at one end of a tie ci rcuit become s the "E " signal o utp ut by th e remote ti e lin e inter face.
The five E&M signaling types are illustrated in the following figure.
E&M PBX T O PBX C ON N ECTI ON
E&M CO NN ECTION T HRO UG H SDM- FP
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