Oki OKIFAX 1050, Service Manual

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In G3 communication, this is the route of the procedural control signals (pre-message, post-message
phases etc.) at 300bps.
The protocol send data is read into DRAM (for OKIFAX 1050)/P-SRAM (for OKIFAX 2350/2450) in the
sequence the contents of varrious data stored in the FLASH memory area in advance under the control of
CPU. The contents of the frame has been edited on the DRAM/P-SRAM by CPU and sent to MODEM via
CPU. HDLC (high level data link control) frame of the data is structured by the modem and converted to
serial data in synchrony with the modems DCLK (data clock). After modulation, the protocol signal is
output from S of the modem and sent to the telephone line L1 and L2 via the transformer T1 of NCU.
3.6.05 300bps Receive Mode
Figure 3.7.3 (For OKIFAX 1050)/Figure 3.8.3 (For OKIFAX 2350/2450) show 300bps receive protocol
signal route.
In G3 communication, this is the route of the procedural 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 and sent from pin R
to Pin RXIN 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/P-SRAM. The written data is interpreted according to bit assigment of the binary procedural signals
in the ITU recommendations. The successive modes of communication (for example, line
density,encoding scheme, etc.) are determind.
3.6.06 Report Printing
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 (for OKIFAX 1050)/P-SRAM (for OKIFAX 2350/2450) 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/P-SRAM. The data is read out from the DRAM/P-SRAM and sent to IOGA.
The data is converted into a serial data by the picture control of IOGA and transferred to the LED print
head for printing as HDATA.
3.6.07 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.
3.6.08 Memory Reception
This signal route describes the memory reception used in no-paper mode, 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 for OKIFAX 1050/P-SRAM for OKIFAX 2350/2450) as such.
In case of printing, When the data for one page has been stored in the memory (DRAM/P-SRAM), the
data is read out from the memory and sent to IOGA. The printed data is converted into a serial data by the
printer control of IOGA and transferred to the LED print head for printing as HDATA.