APS EPM203-MRS, Техническое описание

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EPM203-MRS - Technical reference - Rev. G Page 14
Advanced Printing Systems
4.3 Timing for parallel communication
The communication protocol is Centronics compatible, and has the ability to handle the “Compatibility
Mode” (Write from the Host to the Printer), and also the “Byte Mode”, for the host to read internal data
from the printer. The “Byte Mode” is used to receive printer status back from the printer.
4.3.1 Compatibility mode timing (host writes to the printer)
D0-D7 (Host Output)
STB (Host Output)
BUSY (Printer Output)
ACK (Printer Output)
DATA VALID
tSTB
tACK
tBUSY
tVALDATA
Parameter Min. Typ. Max. Comments
Time STB (tSTB) 5 µs - - This time is given by the host
Time BUSY (tBUSY) 25 µs 90 µs 250 µs
This hold time is controlled by GS b
control code
Time tVALDATA 25 µs - -
Time in while the data must be stable.
This time is fixed by the host.
Time ACK (tACK) - 3µs -
IMPORTANT NOTE
:
The data (D0-D7) must be stable for tVALDATA. If not, please contact APS for additional cabling.