Meridian America 21 Benutzerhandbuch
Characteristics
5
Functional
The Analog Message Waiting Line Card contains a microprocessor that
provides the following functions:
provides the following functions:
card self-identification
self-test
control card operation
status report to the controller
diagnostics for maintenance purposes
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The Analog Message Waiting Line Card also provides the following:
balanced terminating impedance
analog-to-digital and digital-to-analog conversion of transmission and
reception signals for 16 audio phone lines
reception signals for 16 audio phone lines
transmission and reception of SSD signalling messages over a
signalling channel in A10 format
signalling channel in A10 format
detection of on-hook/off-hook status and switchhook flash
connection of 20 Hz ringing signal and automatic disconnection when
the station goes
synchronization for connecting and disconnecting the ringing signal to
zero crossing of ringing voltage
of SSD messages and PCM signals for diagnostic purposes
indication of board status with faceplate-mounted LED
Analog message waiting line card description
553-3001-l 63