Oki OKIPOS408II OKIPOS 408II Programmer s Technical Reference - Page 235

Communication Protocol, DTR Space

Page 235 highlights

1-1-3 Communication Protocol 1) General description of operations in the DTR mode This mode abides by the DIP switch settings. (Ex-factory settings) This mode performs communication while handshaking with the DTR signals. In the operations to receive printer data, this mode controls the DTR signals by confirming the BUSY signal. A SPACE indicates that the printer is ready to receive data; conversely, a "mark" indicates that the printer cannot receive data. RXD DATA DTR Printing operation Power ON Buffer Full RXD OFFLINE DTR Printing operation Paper out Paper out signal Power ON DATA Buffer Empty DATA ONLINE Recover to ONLINE If there is no printer error after turning ON the power, the DTR signal line is set to a SPACE. When the host computer confirms that the DTR signal line is a SPACE, it sends the data text to the RXD signal line. The printer sets the DTR signal line to a "Mark" after the empty area of the data buffer reaches a maximum of 256 bytes. When the host computer confirms that the DTR signal line is a Mark, it stops the transmission of data text to the printer buffer, but at this point as well, the printer is still capable of receiving data, up to the amount of empty space in the data buffer. If the host computer ignores the DTR signal and transmits data, all data exceeding the amount of space in the data buffer is simply discarded. The printer sets the DTR signal line to SPACE again when the amount of empty space in the data buffer increased because of the printing and the data in the buffer is a maximum of 256 bytes. As the empty area in the data buffer increases because of printing, the printer sets the DTR signal line to "SPACE." 2) Buffer full/Buffer full cancel in the DTR mode Full Near Full Buffer Empty area 256 bytes Empty area 512 bytes Near Empty Empty DTR "Mark" DTR "Space" _____ STAR Page Mode Command Specifications 1-2

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____________________________________________________________________________________________________________________________________________
STAR Page Mode Command Specifications
1-2
1-1-3
Communication Protocol
1) General description of operations in the DTR mode
This mode abides by the DIP switch settings.
(Ex-factory settings)
This mode performs communication while handshaking with the DTR signals.
In the operations to receive printer
data, this mode controls the DTR signals by confirming the BUSY signal.
A SPACE indicates that the printer is
ready to receive data; conversely, a "mark" indicates that the printer cannot receive data.
If there is no printer error after turning ON the power, the DTR signal line is set to a SPACE. When the host computer
confirms that the DTR signal line is a SPACE, it sends the data text to the RXD signal line. The printer sets the DTR
signal line to a "Mark" after the empty area of the data buffer reaches a maximum of 256 bytes. When the host
computer confirms that the DTR signal line is a Mark, it stops the transmission of data text to the printer buffer, but at
this point as well, the printer is still capable of receiving data, up to the amount of empty space in the data buffer. If
the host computer ignores the DTR signal and transmits data, all data exceeding the amount of space in the data
buffer is simply discarded. The printer sets the DTR signal line to SPACE again when the amount of empty space in
the data buffer increased because of the printing and the data in the buffer is a maximum of 256 bytes. As the empty
area in the data
buffer increases because of printing, the printer sets the DTR signal line to “SPACE.”
2) Buffer full/Buffer full cancel in the DTR mode
Full
Near Full
Near Empty
Empty
Buffer
Empty area 512 bytes
Empty area 256 bytes
DTR "Mark"
DTR "Space"
<When ONLINE>
RXD
DATA
DATA
DATA
DTR
Printing operation
Power ON
Buffer Full
Buffer Empty
<When Paper is Out>
RXD
OFFLINE
ONLINE
DTR
Recover to ONLINE
Printing operation
Paper out
Paper out signal
Power ON