Circuit Description - Oki OKIPAGE 12i Troubleshooting Manual

3.

CIRCUIT DESCRIPTION

3.1 Outline
The main control board controls the reception of data transferred through a host I/F and processes
command analysis, bit image development, raster buffer read. It also controls the engine and the
operator panel. Its block diagram is shown in Fig. 3-1 and 3-2.
(1) Reception control
OKIPAGE 12i Printer can be equipped with two I/F ports by adding an RS232C I/F or network
I/F option board in addition to the Centronics I/F on the main control board.
Either of the two I/F ports which receives data first can be used automatically.
The other I/F port outputs a busy state signal.
The parallel I/F port can specify the following item when set by the control panel:
I-PRIME: Enabled/Disabled
The serial I/F port can specify the following item when set by the control panel:
Flow control
Baud rate
Data bit
Minimum busy time
Parity
An interface task stores all data received from the host into a receive buffer first.
(2) Command analysis processing
The OKIPAGE 12i printers support PCL6 (Hewlett Packard LJ6P compatible).
An edit task fetches data from the receive buffer, analizes commands, and reconstructs the
data in such a way that print data are aligned from up to down and from right to left; then it
writes the resultant data into a page buffer with such control data as print position coordinate,
font type, etc. added.
(3) Font Processing
When one page editing is finished, a developing task makes an engine start and fetches data
from the page buffer synchronizing with a printing operation; then it developes the fetched
data to a bit map as referring to data from a character generator, and writes the resultant data
into the raster buffer (of band buffer structure).
(4) Raster buffer read.
As controlling the engine operation, an engine task sends data from the raster buffer to the
LED head.
: DTRHI/DTR LO/XONXOFF/RBSTXON
: 300/600/1200/2400/4800/9600/19200 (Baud)
: 7/8 (bits)
: 200/1000 (ms)
: NONE/ODD/EVEN
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