Nortel Circuit Card Installation Manual page 634

Page 634 of 906
Trunk circuit features
553-3001-211 Standard 3.00
NT8D15 E&M Trunk card
Trunk unit functions
The functions provided by each unit on the E&M trunk card include 2-wire
signaling, 4-wire signaling, and paging operation as follows:
• 2-wire, E&M Type I signaling (see Figure 144 on
— 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
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-end
detection by E/SG lead
• 4-wire, DX signaling (see Figure 146 on
• paging trunk operation (see Figure 147 on
by low-resistance path at the PG/A1 leads
Note: Paging end-to-end signaling is not supported.
August 2005
page 635) with:
page
page 637)
page 638) with support access
636),