Nortel Networks 553-3001-211 manual Idle state, CO/FX Wats

Page 630 of 894 NT8D15 E&M Trunk card

Figure 145

Signaling orientation for tandem connection between E&M and CO trunks

	Near end PBX
	(senderized)
Far end PBX		CO
Outgoing
Tie trunk		PBX-CO trunk
Incoming
E&M	CO/FX/
	WATS	553-6262

Idle state

For E&M signaling, in the idle state the M lead is ground and the E lead is an open circuit.

Outgoing calls are processed as follows:

•The M lead changes from ground to battery.

—If answer supervision is provided by the far end, there is a change from open to ground on the E lead (ground detection).

553-3001-211 Standard 2.00 September 2004