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3. CIRCUIT DESCRIPTION
3.1 Outline
ThemaincontrolboardcontrolsthereceptionofdatatransferredthroughahostI/Fandprocesses
commandanalysis, bitimagedevelopment,raster bufferread.Italso controlstheengineand the
operator panel. Its block diagram is shown in Fig. 3-1 and 3-2.
(1) Reception control
OKIPAGE12iPrintercanbeequippedwithtwoI/FportsbyaddinganRS232CI/Fornetwork
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 : DTRHI/DTR LO/XONXOFF/RBSTXON
Baud rate : 300/600/1200/2400/4800/9600/19200 (Baud)
Data bit : 7/8 (bits)
Minimum busy time : 200/1000 (ms)
Parity : NONE/ODD/EVEN
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
writestheresultantdataintoapagebufferwithsuchcontroldataasprintpositioncoordinate,
font type, etc. added.
(3) Font Processing
Whenonepageeditingisfinished,adevelopingtaskmakesanenginestartandfetchesdata
from the page buffer synchronizing with a printing operation; then it developes the fetched
datatoabitmapasreferringtodatafromacharactergenerator,andwritestheresultantdata
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.
