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553-3023-211 Standard 1.00 June 2001
NT8D15 E&M Trunk Card
Incoming calls
The far-end initiates calls as follows:
•
The ground is placed on the E lead in E&M signaling.
•
Dial pulses are subsequently applied from the far-end as ground open on
the E lead.
•
If the far-end is equipped for sending, the system may be operated in any
mode (immediate start, delay dial, or wink start), as assigned on a start
arrangement basis. See Table 17.
— In immediate start mode, there is no start signal from the called
office. The seizure signal (off hook supervisory state) from the far-
end should be at least 150 ms. At the end of the seizure signal, the
far-end may start pulsing after the standard delay (normally 70 ms
minimum).
— In delay dial mode, a 256–384 ms off hook/on hook signal is
returned to the far-end immediately after receipt of the seizure
signal. When the far-end detects the on hook signal (start signal), the
far-end may start pulsing after the standard delay (normally 70 ms
minimum).
— In wink start mode, within a 128–256 ms period after receipt of the
seizure signal from the far-end, the called office transmits a 250 ms,
wink start, off hook/on hook signal to the calling office.
Table 17
Operation mode
Operation mode
Immediate start
Delay dial
Wink start
Start arrangement
IMM
DDL
WNK