Reliability - Northern Telecom M5212 ACD General Description, Installation And Maintenance

2-2 Specifications
One feature button is permanently assigned to toggle the handset mute on or
off. The mute handset LCD indicator will indicate the following states:
Table 2-2xxx
Mute handset LCD indicators
On/Off Hook - Mute On/Off
Handset on-hook
Handset off-hook - mute off
Handset off-hook - mute on
During operations with a headset connected, the default state for handset
operations is mute on. Pressing the MUTE button one time during a call
places the handset into mute off mode. Once the handset is in the mute off
mode, it will not return to a muted mode until the MUTE button is pressed
again, the handset is placed on-hook, or the REALEASE (Rls) key is
pressed.
Volume control
The VOLUME CONTROL rocker key controls independent volume levels
for the headset, handset, ringer, and speaker. A visual bar indication is
shown on the main display whenever the VOLUME CONTROL key is used.
Headset volume is controlled only during an active call with the handset
on-hook. Once it has been set, the headset volume setting will be
maintained unless auxiliary power is lost to the M5212, the headset is
disconnected, or the volume setting is changed.
Handset volume is controlled during an active call with the handset
off-hook. Once it has been set, the handset volume setting will be
maintained unless power is lost to the M5212, the handset is placed
on-hook, or the volume setting is changed.
Speaker volumes may be adjusted during on-hook dialing and listen on hold.
In addition, the ringer volume can be adjusted while the handset and headset
are seated. Changes to the ringer and speaker volume settings are
maintained as long as auxiliary power is not lost.

Reliability

MTBF (mean time between failure) predictions were made using the
Product Integrity MTBF component database.
297-2041-900 Standard 02.01 October 1991
LCD State
LCD Off
LCD Off
LCD winking