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Board Descriptions
A - 51
OKIOFFICE 44 Serv. Man., P/N 59276801
A3.7
UNC5 (NCU) Circuit Diagram
Note: The relationship between NCU and optional boards (NTIF, TEL, HOOK, etc.) are shown in
A3.11.
1.
Block diagram
•
Figure A3.7.1 shows a block diagram of UNC5 circuit.
2.
General functions of this circuit are as follows:
1)
Generates and detects signals to be exchanged with a telephone exchange or network in
Phases A and E defined by ITU T.30.
•
Loop formation for call origination
•
Line current detection (see note 1) before call origination
•
Dial tone detection (see note 1)
•
Generation of dial pulses (see note 2)
•
Busy tone detection (see note 1)
•
Ringing signal detection
2)
Sends various data and signals from the R44/M17 board to the telephone line after amplifi-
cation.
•
Picture data/Protocol/Tonal signals/PB tone, etc.
3)
Sends the following signals received from the line to the R44/M17 board as data after
amplification.
•
Picture data/Protocol/Tonal signals, etc.
Note 1: This procedure may be omitted depending on the dial parameters.
Note 2: MF (Multi-frequency) tone is generated by the modem and transferred to the
telephone line via the NCU board.
Summary of Contents for OKIOFFICE 44
Page 2: ...All specifications are subject to change without notice Service Manual OKIOFFICE 44 59276801...
Page 135: ...Disassembly 4 6 OKIOFFICE 44 Service Manual P N 59276801 Whole Unit Picture FX048 CP4 1 Fig 01...
Page 329: ...Illustrated Parts List D 6 OKIOFFICE 44 Service Manual P N 59276801 Section 2 Printer Unit...
Page 331: ...Illustrated Parts List D 8 OKIOFFICE 44 Service Manual P N 59276801 Section 3 Operator Panel...
Page 351: ...Illustrated Parts List D 28 OKIOFFICE 44 Service Manual P N 59276801 Section 12 Cables...
Page 357: ...Board Layout E 2 OKIOFFICE 44 Service Manual P N 59276801 MEM eps E 2 MEM PCB...
Page 358: ...Board Layout E 3 OKIOFFICE 44 Service Manual P N 59276801 TEL U eps E 3 TEL U PCB...
Page 359: ...Board Layout E 4 OKIOFFICE 44 Service Manual P N 59276801 Hook eps E 4 Hook PCB...
Page 388: ...OKIOFFICE 44 Service Manual Part Number 59276801 Printed in the USA...