Sharp FO-475TH Service Manual page 52

[Signals for status recognition according to input signals]
Signal Name
H: The handset is in the on-hook state.
RHS
L: The handset is in the off-hook state.
CI Incoming call (CI) detection signal
H: The handset or external telephone is in the
on-hook state.
HS
L: The handset or external telephone is in the
off-hook state.
[Other signals]
Signal Name
TEL IN Receiving signal from line or modem
TEL OUT Transfer signal to line
SPOUT Speaker output signal
Transmission (DTMF) analog signal output
TXOUT
from modem
Reception (DTMF, others) analog signal input
RXIN
into modem
(Example: TEL speaking)
TEL LINE
HS DETECTOR
EXT
HANDSET
HOOK SW
TX/RX SIGNAL
OGM/ICM/MEMO/PLAYBACK SIGNAL
OGM/MEMO/RECORD SIGNAL
Function
Function
TEL/LIU PWB
H
L
CI DETECTOR
TELIN
TELOUT
SP AMP
SPEAKER
NO Signal Name (CNLIU)
1 TELOUT
2 TELIN
3 TELMUTE
4 CI
5
HS
6 RHS
CONTROL PWB
HS
CML
GAIN-C
TXOUT
0
RXIN
1
1
0
VOL A
VOL B
VOL C
4051
TEL MUTE
CI
RHS
+5V
+24
DG
Fig. 6
5 – 10
NO Signal Name (CNLIU)
7
8 TXOUT
9
10
11
12
TXCONT
SIGTX
1
MODEM
4053 (R96V24)
0
1
0
SIGRX
1 0
BZCONT
0
1
TXCONT
RXCONT
MONITOR
BZCONT
FC200
RCVOL
SP MUTE
TEL MUTE
CI
UX-258TH
FO-475TH
RXIN
CML
+24VA
+5V
DG
GAIN-C
CML
HS