Oki OKIFAX4550 Maintenance Manual page 319

IC8
Modem
IC2
IOGA4
Figure A.12 (1/4) Interface between 46F Board and NCU Board
IC2
TXDOPE
RXDOPE
PSMODE
IOGA4
OPRST-N
OPECHK
+5 V
0 V
PCI-N
RIINT
HUP-N
Figure A.12 (2/4) Interface between 46F Board and OPE (operation unit)
41309401TH Rev.4
46F
S
RP
R
CML
DP
SR
MUTE
PBXE
OH2
to OPE
RI
to OPE
46F OPE (04W)
CN4 CN1
TXD
1
RXD
2
3 PSMODE
4
IRST
5
OPECHK
6,7
8,9
13
14
15
NCU
CN10 CN3
S
A4
A1
A2 R
A16
A15
A12
Relay driver circuit
A17
A13
A8
Hook-up signal
detection circuit
A6
Ringing signal
detection circuit
X'tal
IC1
MOS CPU
Internal ROM
+5 V
GND
Eight LEDs
LEDs
Receiving
sensitivity control
KSCAN0
to
KSCAN7
Key switch
matrix
KSENS0
to
KSENS7
DB0
to
DB7
LCD unit
Control signals
319 /