Because RFL™ and Hubbell® have a policy of continuous product improvement, we reserve the right to change designs and specifications without notice.
FUNCTIONAL DESCRIPTION
Figure 5 is a simplified block diagram of the RFL VF-15C module. The module consists of two
independent audio circuits which share digital interface and control logic circuitry. Each of the audio
circuits contains a Data Access Arrangement (DAA) hybrid circuit which serves as the interface to the
telephone line. The hybrid contains circuitry for combining the transmit and receive audio, controlling
loop current, and ring voltage detection. The hybrid also provides the required isolation of the external
signals.
The audio signals (both transmit and receive) are processed by a volume control circuit to adjust
levels. The analog-to-digital (A/D) and digital-to-analog (D/A) conversions and companding are
performed by CODECs.
The interface to the multiplexer backplane is performed by bus drivers and receivers. All of the
controlling logic functions are contained in the logic array. This custom device reads the local
switches, controls the LEDs and audio circuits, and interfaces to the bus and common logic module.
LOGIC
ARRAY
BUS DRIVERS
AND RECEIVERS
PCM
CODEC
DIP SWITCH
SW1
DATA
ACCESS
ARRANGEMENT
VOLUME
CONTROL
TIP RING TIP RING
TX AND RX
TEST POINTS
TO/FROM
IMUX 2000
DATA BUS
CH1 RING
CH1 BUSY
CH2 RING
CH2 BUSY
SERVICE
PCM
CODEC
VOLUME
CONTROL
DATA
ACCESS
ARRANGEMENT
DIP SWITCH
SW3
DIP SWITCH
SW9
DIP SWITCH
SW2
DIP SWITCH
SW4
DIP SWITCH
SW10
TX AND RX
TEST POINTS
TX AND RX
TEST POINTS
TX AND RX
TEST POINTS
CHANNEL 1
CHANNEL 2
Figure 5. Functional block diagram, RFL VF-15C module.
RFL VF-15C RFL Electronics Inc.
August 7, 2012 16 (973)
334-3100
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