M2317Telephone Page277 of 544
Option11C and 11C Mini TechnicalReference Guide
Line engineering
The maximum permissible loop length is 1067 m (3500 ft.) of 22 or 24 AWG
or 760 m (2500 ft.) of 26 AWG standard twisted wire with no bridge taps or
load coils. The 1067 m (3500 ft.) loop length requires the use of a Digital Line
Card (DLC).
Powering requirements
The M2317 Telephone uses loop power for all circuits requiring +10V. In
order to satisfy the power requirements for those circuits on a maximum loop
60 mA of 13.5 V DC must be available at the telephone. The line card must
have compatible voltage and source resistance to meet these requirements.
The Logic circuits of the M2317 Telephone require + 5 V DC which must be
supplied from an external, regulated DC supply which connects through a
jack in the back of the telephone. If the telephone is equipped with a data
option, the required 5 V DC is provided by the external data option power
supply. The external power supply must meet the following specifications:
Input: 95 - 129 V AC, 60 Hz
Output: +5 V DC, + or - 5%, 300 mA
10 mV maximum RMS ripple
Cord: 2.5 m (8 ft.) of 20 AWG wire mating to a
Switchcraft 722A connector
Case: Wall mounted, CSA and UL approved.
Operational with in 0° C (32°F) and 50°C
(122°F) temperature limits
Impedance: Greater than 10 M¾ to ground
The external power supply, in all cases where no asynchronous data option is
installed, is connected to the mating connector mounted in the rear of the
M2317 Telephone, covering the area where the RS-232-C interface connector
would be located.
If the Asynchronous Data Option is installed, an external, multi-output data
power supply NPS50220-03L5 is required. This power supply satisfies all
powering requirements for the telephone and the data option.