Eee1284.4 Protocol - Epson STYLUS COLOR 580 Service Manual

EPSON Stylus COLOR 580

1.3.2 EEE1284.4 Protocol

The packet protocol described by IEEE1284. 4 standard allows a device to carry on
multiple exchanges or conversations which contain data and /or control command with
another device at the same time across a single point-to-point link. The protocol is not,
however. a device control language. It dose provide basic transport-level flow control
and multiplexing services. The multiplexed logical channels are independent of each
other and blocking of one has no effect on the others. The protocol operates over
IEEE1284.4.
Three function modes of IEEE1284.4 protocol, "On", "Off" and "Auto" are available ,
and the setting is defined based on the data stored in the value in EEPROM address
25<H>.
o
On
Communication in IEEE1284.4 packet mode is started by receiving a magic string
(1284.4 synchronous commands). Until a magic string is received, other
commands are discarded.
o
Off
Communication is carried out in the conventional mode. A magnetic string
(1284.4 synchronous commands) is discarded.
o
Auto
Communication is carried out in the conventional mode until a magic string
(1284.4 synchronous commands) is received. By receiving a magic string,
communication in IEEE1284.4 packet mode is started.
The factory setting for IEEE1284.4 mode is "ON". But, after complete the initial ink
charge operation, the setting of the EEPROM is set to "AUTO". The change in this
setting will be effective when the power is back on after the initial ink charge
operation.
Product Description Interface Specification
Revision A
22