Nortel Networks M3110 - Manual (Page 466)

Page 466 of 504 Appendix E: M3110, M3310, and M3820 telephones
553-3001-367 Standard 3.00 August 2005
Meridian digital telephones used with a headset
You can use an electret headset in the headset port of the digital telephones
(M3310 and M3820 only). Alternatively, choose an amplified headset that
draws power from a battery or AC transformer; power is not provided by the
telephone. The amplifier must draw less than 400 micro amps from the
telephone jack.
The headset should be designed to work with a telephone jack with these
characteristics:
Transmit interface: +5 V through 10K DC bias resistance with maximum
current of 500 micro amps. The differential input impedance is 10K ohms.
Connects to pins 2 and 5 of the headset jack.
Receive interface: single ended output with output impedance of 180 ohms.
Connects to pins 3 and 4 of the headset jack.
Physical description
Meridian digital telephones support many general features as illustrated in
Table 76.
Table 76
Meridian digital telephone general features (Part 1 of 2)
Feature M3820 M3310 M3110
Handsfree, On-Hook Dialing, and Group Listening yes yes yes
Dedicated Release and Hold keys yes yes yes
Message Waiting and Speaker/Mute Indicators yes yes yes
Headset Socket yes yes no
2 x 24 character display yes yes no
Feature keys including: 20 10 10
• Store/program key yes yes no
• system programmable keys 13 7 8