Carrier Access SNMP manual Typical Applications, Physical Description

4-Wire E&M/TO Configuration

ropolitan area networks. Each of the twelve E&M channels can be individually configurted to support Signaling Types I, II, IV or V, using up to 4 signaling and transmission pairs per channel (E/M, SG/ SB, T/R, and T1/R1). This card can be configured to function as Channel Equipment (normal multi- plexer mode) or as Switching Equipment for back-to-back Tandem applications sometimes referred to as Reverse E&M or Pulse Link Repeater (PLR).

11.2.2 Physical Description

Like the FXS and FXO/DPT voice cards, the 4-wire E&M/TO is a 7.8” by 13.16” daughter card that slides into the back of the Access Bank II - SNMP (AB2 - SNMP) along rails that guide a 64-pin DIN connector to mate with a matched connector on the internal ABI Controller. The E&M/TO card receives T1 signaling, control logic, and -48 Vdc power through this connector from the Controller card. Because the RJ-21X Amphenol Telco connector on the ABI front control panel fails to pro- vide enough wiring leads, it is bypassed through a 96-pin E&M signaling line connector attached on the opposite end of the card. The E&M signaling lines (E, SG, M, SB, T, R, T1 and R1) are connected to this high-density 96-pin DIN connector. A bank of 12 channel status LEDs are located next to the E&M signaling line connector on the ABI back plate. Each channel has jumpers that allow the chan- nel to be configured for E&M Types I, II, IV and V signaling. Each channel also has a 10-position DIP switch that allows the receive and transmit attenuation to be individually set from -22 dB to +10 dB. There is also a 4-position DIP switch located next to the processor for setting regular or clear channel E&M signaling types and selecting busy or idle during carrier failure.

11.3 Typical Applications

The major applications for the 4-wire E&M/TO voice card are E&M Tie Lines operating in either Normal or Tandem mode. This interface also supports two-way Direct Inward Dial (DID) applica- tions. See Figure 11-1and Figure 11-2below for pictorial representations of these typical applica- tions.

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