Oki OKIFAX 5400 Maintenance Manual page 275

SIGNAL FLOW
(5) 300bps Receive Mode
Figure A2.5 shows 300bps receive protocol signal route
In G3 communication, this is the route of the procedual control signals (pre-message, post-
message phases etc.) at 300bps.
The 300bps modulated signals received via the telephone line L1 and L2 of the NCU are sent
from pin R to pin RXA1 of the modem. After demodulation by the modem, the demodulated
digital signals are sent to the CPU via the data bus from the modem.
The data is read and decoded by the CPU and written into the DRAM. The written data is
interpreted according to bit assignment of the binary procedural signals in the ITU recommen-
dations. The successive modes of communication (for example, line density, encoding
scheme, etc.) are determined.
(6) Report Printing
Figure A2.6 shows the report printing signal route
This signal route describes the printing route of character data used to print Activity Report,
Message Confirmation Report, etc.
The report data is read into DRAM in the sequence the contents of data stored in the FLASH
memory in advance under the control of CPU. The contents of data is edited on the DRAM.
The data is read out from the DRAM and sent to CPU. The data is converted into a serial data
by the picture control of CPU and transferred to the LED print head for printing as HDATA0.
(7) Memory Transmission
This signal route describes the memory transmission used in broadcast mode, delayed
broadcast mode, etc,)
The stored encoded data undergoes buffering, passes through CPU, Modem and NCU and
then sent out to the telephone line.
(8) Memory Reception
This signal route describes the memory reception used in no-paper, no-toner reception,
confidential mode, etc.
The encoded data received by the same route of (3) G3 receive mode undergoes the picture
data processing and stored into memory (DRAM) as such. In case of printing, when the data
for one page has been stored in the memory (DRAM), the data is read out from the memory
and sent to CPU. The printed data is converted into a serial data by the printer control of CPU
and transferred to the LED print head for printing as HDATA0.
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