Page 640 of 894 NT8D15 E&M Trunk card
553-3001-211 Standard 2.00 September 2004
Note: * – CO ground start: the trunk is idled and the network taken
down, but the incoming tie trunk is controlled by the originating end.
Electrical specifications
Table 197 lists the electrical characteristics of the trunk interface on the E&M
trunk card.
Table 197
Electrical characteristics of E&M trunk cards
Characteristic 4-wire trunk 2-wire trunk
Signaling range Type I 150 ohms
Type II 300 ohms
loop
Type I 150 ohms
Signaling type Type I, Type II Type I
Far-end battery –42 to –52.5 V dc –42 to –52.5 V dc
Near-end battery –42.75 to –52.5 V dc –42.75 to –52.5 V dc
Ground potential difference +10 V dc +10 V dc
Line leakage between E lead
and ground
Š20K¾ Š20K¾
Effective loss See pad table (Table 204 on
page 650)
See pad table (Table 204 on
page 650)
Terminating impedance 600 ohms 600 ohms
Balance impedance N/A 600 ohms
Table 198
Electrical characteristics of trunk cards (Part 1 of 2)
Characteristic DID Trunk CO trunk
Nominal impedance 600 or 900 ohms, (selected
by software)
600 or 900 ohms, (selected
by software)
Signaling range 2450 ohms 1700 ohms