Sharp FO-90 Service Manual page 38

FO-90RA
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 photo coupler which is integrated in series in
the primary side TEL circuit well proven in the existing unit.
VOLUME SETTING
VOL A
OUTPUT VALUE (GP02)
X 0 1K 0
X 1 10K 1
X 2 39K 0
X 3 100K 1
X 4 200K 0
X 5 300K 1
X 6 470K 0
X 7 750K 1
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
(The circuit is located
in the TEL/LIU PWB.)
SP MUTE
(The circuit is located
in the TEL/LIU PWB.)
TEL MUTE
DPON
(The circuit is located H: Line connect / Make
in the TEL/LIU PWB.)
DPMUTE
(The circuit is located H: Muting
in the TEL/LIU PWB.)
TXMUTE
(The circuit is located H: Muting
in the control PWB.)
VOL B VOL C ON-HOOK ICM/OGM ICM/OGM
(GP03) (GP04) Receiving MONITOR
0 0 —
0 0 HIGH
1 0 MID 1
1 0 MID 2
0 1 MID 3
0 1 —
1 1 LOW
1 1 —
5 – 10
Description
Line connecting relay
H: Line make
L: Line break
Speaker tone mute control signal
H: Muting (Power down mode)
L: Muting cancel (Normal operation)
Handset reception mute control signal
H: Muting
L: Muting cancel
Connecting DC circuit and DP generating
L: Line disconnect / Break
Adjust the resistance during make ratio
L: Muting cancel
Tx route mute circuit
L: Muting cancel
PLAY RINGER
— HIGH HIGH
HIGH MIDDLE1 —
MID 1 MIDDLE2 —
MID 2 MIDDLE3 —
MID 3 LOW MIDDLE
— — —
LOW — —
— — LOW
BUZZER DTMF/DP
— —
— —
— —
— —
— —
— FIXED
FIXED —
— —