Signal Selection; Ci Detection Circuit; Signal/Dtmf Transmission Level & Receiving Level - Sharp FO-71 Service Manual

5. CI detection circuit

•
CI is detected by the photo coupler which is integrated in series in
the primary side TEL circuit well proven in the existing unit.
6. Signal/DTMF transmission level & receiving level
•
Signal transmission level setting: According to soft switch list.
•
DTMF transmission level setting: According to soft switch list.

4) Signal selection

The following signals are used to control the transmission line of TEL/
FAX signal. For details, refer to the signal selector matrix table.
[Control signals from output port]
Signal Name
CML Line connecting relay and DP generating relay
H: Line make
(The circuit is located
L: Line break
in the TEL/LIU PWB.)
MIC MUTE Handset transmission mute control signal
H: Muting
(The circuit is located
L: Muting cancel
in the TEL/LIU PWB.)
Handset reception mute control signal
TELMUTE H: Muting
L: Muting cancel
DTMFMUTE control signal
Volume
DTMFMUTE
DTMFMUTE
(The circuit is located
in the control PWB.)
Note: The DTMF sending listed above is DTMF signal
VOLUME SETTING
DTMF Transmission
volume setting (Receiver)
Key buzzer volume setting Fixed
Speaker volume setting
Ringer volume setting
DTMF speaker volume
setting
5 – 10
Description
High
Middle Low DTMF sending
L L H
sending in the handset OFF-HOOK mode.
LINEOUT A RCVOL DTME
(HIGH) (LOW)
Fixed 1
Low 1 1
Middle 1 0
High 0 1
Low 1 1
Middle 1 0
High 0 1
Low 1 1
Middle 1 0
High 0 1
FO-71RA
FO-51RA
H
MUTE
1