Sharp FO-70 Service Manual page 58

FO-50RA
FO-70RA
5. Externally connected TEL OFF HOOK detection circuit section
•
The circuit current detection is turned on together with OFF HOOK
of main body or OFF HOOK of externally connected TEL. ON of
CML OFF (HS=L) is judged as OFF HOOK of externally connected
TEL.
6. CI detection circuit
•
CI is detected by the photocoupler which is integrated in series in
the primary side TEL circuit well proven in the existing unit.
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.)
SP MUTE Speaker tone mute control signal
H: Muting (Power down mode)
(The circuit is located
L: Muting cancel (Normal operation)
in the TEL/LIU PWB.)
Handset reception mute control signal
TEL MUTE H: Muting
L: Muting cancel
VOLUME SETTING
DTMF Transmission
volume setting (Receiver)
Key buzzer volume setting
Speaker volume setting
Ringer volume setting
DTMF speaker volume setting
5 – 10
Description
LINEOUT A
(HIGH) (LOW)
Fixed
Fixed
Low 1 1
Middle 1 0
High 0 1
Low 1 1
Middle 1 0
High 0 1
Fixed