Page318 of 544 M3900telephone series
553-3011-100 Standard14.00 January 2002
Environmental and safety co nsiderations

Temperature and humidity

Line engineering
Meridian Digital telephones use twisted pair wiring on transmission lines
selected by the rules given in Digital Telephone Line Engineering (553-2201-
180). The maximum permissible loop length is 3500 ft. (1067 m), assuming
24 AWG (0.5 mm) standard twisted wire with no bridge taps. A 15.5 dB loss
at 256kHz defines the loop length limit. (Longer lengths are possible,
depending on the wires gauge and insulation.).
Note: Use only the line cord provided with the telephone. Using a cord
designed for another telephone could result in damage to the cord.
HEAD
SET
EXT.ATR* OK OK OK OK OK OK OK N/A XOK X
HD SET OK OK OK OK OK OK OK XN/A OK OK
GPIO
EXT.ATR OK OK OK OK OK OK OK OK OK N/A OK
RCDR OK OK OK OK OK OK OK XOK OK N/ A
Operating state:
Temperature range 0° to 50°C (32° to 104°F)
Relative humidity 5% to 95% (noncondensing). At temperatures
above 34°C (93°F) relative hum idity is limited
to 53 mbar of water vapor pressure.
Storage:
Temperature range 50° to 70°C (58° to 158°F)
Relative humidity 5% to 95% (noncondensing). At temperatures
above 34°C (93°F) relative hum idity is limited
to 53 mbar of water vapor pressure.
Table 9 6
M3900 Series Meridian Digital Telephone accessory compatibility (Part2 of 2)
HW Port SDI
SIDL +
USAR
T
USAR
TUART HEADSET GPIO