Voice Config ura tion Reference I nf ormation C-13
E&M Wiri ng
In a two-wire E&M application, connect red and green wires to the PBX's RT and RR
pair, respectively. The RT and RR pair carry voice or fax analog signals between the
SmartSwitch 1800 and the PBX.
In a four-wire E&M application , conne ct red and green wires to the PB X's RT and RR
pair, and black and yellow wires to the PBX's TR and TT pair, respectively. The RT
and RR pair carry voice or fax analog signals from the SmartSwit ch 1800 to the PBX.
The TR and TT pair carry voice or fax analog signals from the PBX E&M tie trunk to
the SmartSwitch 1800.
Connect the signaling wires as indicated in the following table.
Normally, when PBX-to-PBX E&M tie trunks are installed, the "E" lead of one PBX
is normally crossed over and connected to the "M" lead of the other PBX, and vice
versa. In a multiplexer application the crossover is accomplished digitally, therefore,
when connecting a PBX to the system in E&M mode, the "E" and "M" leads of the
PBX connect to the "E" and "M" leads of the cable from the SmartSwitch straight
throug h, wit ho ut cros s ing.
Table C - 2 E&M Wiri ng
E&M
Signaling Type Connections
I, V Connect Blue wire to the "E", Orange wire to the "M" and Brown wires to the
"SG" (or common ground) PBX leads.
II, IV Connect Blue wire to the "E", Brown w i r e to t he "SG ", Orange wire to the "M"
and Gray wire s to the "S B" PBX leads.
III Connect Blue wire to the "E", Orange wire to the "M" and Gray wir e to the
"SB" PBX leads. Connect Brow n wire t o "SG" or co mmon ground.