OPERATION
A RED LED INDICATOR LIGHTS WHEN AN ALARM
CONDITION EXISTS IN THE CHANNEL. SOME
POSSIBLE ALARM CONDITIONS ARE: TRANSMIT
CLOCK BAD, RECEIVE CLOCK BAD, CHANNEL OUT
OF SYNC AND DIAGNOSTIC TESTS IN PROGRESS.
THE LED ALSO LIGHTS IF THE CARD IS INSTALLED
IN AN UNDEFINED SLOT.
I n S v c e
CELP
VOICE
CHAN
E
M
C h a n
A l m
L E V E L
AMBER LED LIGHTS WHEN THE E-LEAD
OF THE VOICE CHANNEL IS IN A BUSY
STATE. OUTPUT FROM THE VOICE
CHANNEL IS IN THE FORM OF A SOLID
STATE SWITCH. LOW RESISTANCE
EQUALS A BUSY CONDITION (E-LEAD
TO GROUND). E-SIGNAL IS A PRODUCT
OF THE REMOTE CHANNELS M-SIGNAL.
A GREEN LED INDICATOR LIGHTS WHEN THE
CHANNEL IN THE CURRENTLY ACTIVE TDM
CONFIGURATION,INDICATING THAT THE CARD IS
EITHER OPERATING OR PREPARED TO OPERATE
ACCORDING TO THE PARAMETERS ENTERED FOR
THAT CHANNEL IN THE ACTIVE CONFIGURATION.
WHEN OFF, THE CHANNEL IS OUT OF SERVICE.
WHEN OUT OF SERVICE, THE CONTROL LEADS
ARE CONDITIONED.
TEST POINT FOR BRIDGED MEASUREMENT OF
VOICE CHANNEL VF INPUT LEVEL TO THE
TRANSMIT SECTION. TEST POINT ISOLATED
THROUGH 10-KILOHM RESISTOR. INPUT
LEVELS SHOULD BE 0 dBm OR –16.0 dBm. THIS
TEST POINT IS A HIGH IMPEDANCE INPUT AND
IS NOT FOR INJECTION OF TONES.
V F I n
V F O u t
G n d
S I G N A L
AMBER LED LIGHTS WHEN THE M-LEAD
OF THE VOICE CHANNEL IS IN A BUSY
STATE.
TEST POINT FOR BRIDGED MEASUREMENT OF
VOICE CHANNEL VF OUTPUT LEVEL FROM THE
RECEIVE SECTION. TEST POINT ISOLATED
THROUGH 10-KILOHM RESISTOR. OUTPUT
LEVELS SHOULD BE 0 dBm OR +7.0 dBm
ANALOG GROUND POINT FOR VF INPUT
AND VF OUTPUT MEASUREMENT.
NOTE
The E&M and Alarm indicators are still functional
when the card is not in service.
FIGURE 3-1. CELP VOICE CHANNEL MODULE, FRONT PANEL
3-2
