Page 634 of 906 NT8D15 E&M Trunk card553-3001-211 Standard 3.00 August 2005Trunk circuit featuresTrunk unit functionsThe functions provided by each unit on the E&M trunk card include 2-wiresignaling, 4-wire signaling, and paging operation as follows:• 2-wire, E&M Type I signaling (see Figure 144 on page 635) with:— near-end seizure and outpulsing with M lead— ground detection with E lead— voice transmission through tip and ring for transmit and receive• 4-wire, E&M Type I and II signaling (see Figure 145 on page 636),2-way dial repeating with:— echo suppression for Type I signaling— switchable 7 dB and 16 dB pads for carrier interface— voice transmission and reception through two separate paths— Type I signaling through E&M leads— Type II signaling with near-end seizure by SB/M leads and far-enddetection by E/SG lead• 4-wire, DX signaling (see Figure 146 on page 637)• paging trunk operation (see Figure 147 on page 638) with support accessby low-resistance path at the PG/A1 leadsNote: Paging end-to-end signaling is not supported.
