Oki OKIOFFICE 84 Service Manual page 394

A3.1.7 R51 Circuit Diagram (Page 7/12)
1. Block diagram
The circuit diagram shown on page 8/12 consists of the following connectors:
l
Connector CN10 that provides an interface between R51 board and NCU board.
l
Connector CN3 that provides an interface between R51 board and external electro-mechanical
components (PC1 and PC2).
l
Connector CN4 that provides an interface between R44 board and OPE (O4W) unit.
Figure A3.1.7 shows an interface between R51 board and NCU board.
Figure A3.1.8 shows an interface between R51 board and OPE unit.
Figure A3.1.9 shows the related signals of PC1 and PC2.
2. Function
1) External status supervising interface (PC1/PC2)
External status is detected by the photocouplers (PC1/PC2) in the mechanism and the signal is output to the input
port of CPU via this interface circuit.
l
PC1: Presence of document on hopper.
When sub-power supply is applied to the fax machine, this signal is output to OPE unit which will control the
main-power supply.
l
PC2: Presence of document at scanning position.
3. Others
NCU interface signal
l
CML : Line seizure control signal
l
DP : Dial pulse control signal
l
SR : Control signal for connection between LINE and TEL terminals
l
MUTE : Control signal for pulse dial improvement and bell shunt relay
l
PP : Relay control signal for special service code detection at parallel pickup or remote reception
l
PBXE : Control signal for connecting one of LINE terminal to the PBXE terminal
l
OH2-N : Detection of off-hook of terminal connected to TEL-1 or TEL-2
l
OH1-N : Output upon circuit current detection after fax line seizure
l
RP : Receiving sensitivity determination terminal
l
RI : Ringing detection signal
Service Guide OKIOFFICE 84
Chapter A Board Descriptions
Page: 235