[Signals for status recognition according to input signals]
Signal Name
Function
RHS
H: The handset is in the on-hook state.
L: The handset is in the off-hook state.
CI
Incoming call (CI) detection signal
HS
H: The handset or external telephone is in
the on-hook state.
L: The handset or external telephone is in the
off-hook state.
P.E
H: No recording paper.
L: Recording paper exists.
[Other signals]
Signal Name
Function
TEL IN
Receiving signal from line or modem
TEL OUT
Transfer signal to line
SPOUT
Speaker output signal
TXOUT
Transmission (DTMF) analog signal output
from modem
RXIN
Reception (DTMF, others) analog signal
input into modem
NO
Signal Name (CNLIUA)
NO
Signal Name (CNLIUB)
1
PC-RLY
1
TELIN
2
+24V
2
TELOUT
3
DG
3
TXOUT
4
+5V
4
RXIN
5
CML
5
TEL MUTE
6
CI
6
P. E
7
HS
7
VREF
8
RHS
8
SP MUTE
9
SPOUT
(Example: Fax signal send)
10. Sensor circuit
For the recording paper sensor (P.E), when there is recording
paper, the photo transistor in the light receiving side is ON and the
detection level is LOW. When there is no recording paper, the
photo transistor in the light receiving side is OFF and the detection
level is HIGH.
11. Cl detection circuit
The CI detection circuit detects the CI signals of 15.3 Hz to 68 Hz.
A CI signal, which is provided to the photo-coupler PC3 through
the C1 (0.82 uF), R2 (22 K), and ZD3 when the ring signal is
inputted from the telephone line, is filtered by the R8 and C12,
and then transmitted to the control PWB through the Q3.
12. Power supply and bias circuits
The voltages of +24V and +5V are supplied from the control PWB
unit.
Fig. 7
OGM/MEMO RECORD SIGNAL
TX/RX SIGNAL
OGM/ICM/MEMO PLAYBACK SIGNAL
LINE
SIG TX
H
L
EXT.
CML
RXIN
TXCONT
TXOUT
CI
DETECTOR
SEL C
GAIN-C
SEL A
SIG RX
TELIN
TELOUT
MPX B
MPX C
SPOUT
+5V
+24VA
DG
VREF
P. E
SPMUTE
TXCONT
MPX B
MPX C
SP MUTE
TEL MUTE
CI
RHS
SEL A
CML
HOOK SW
LIU PWB
CONTROL PWB
1
0
1
0
1
0
MODEM
(R144V24)
VOL A
VOL B
VOL C
X0
X1
X2
X7
1
0
0
1
1
RXCONT
MONITOR
XFC-MVP
SEL C
GAIN-C
SEL A
CML
Handset
Speaker
FO-1850TH
5 – 11
Summary of Contents for FO-1850
Page 65: ...M E M O FO 1850TH 5 13 ...
Page 73: ...Control PWB parts layout Top side 6 8 FO 1850TH ...
Page 74: ...Control PWB parts layout Bottom side 6 9 FO 1850TH ...
Page 76: ...TEL LIU PWB parts layout 6 11 FO 1850TH ...
Page 78: ...6 13 Power supply PWB parts layout FO 1850TH ...
Page 81: ...Operation panel PWB parts layout 6 16 FO 1850TH ...
Page 83: ...Joint PWB parts layout 6 18 FO 1850TH ...
Page 96: ...M E M O FO 1850TH 8 9 ...