Ieee 1284.4 Protocol - Epson Stylus Photo 720 Service Manual

EPSON Stylus Photo 720 / EPSON Stylus Photo EX3

1.3.4.3 IEEE 1284.4 protocol

The packet protocol described by IEEE1284.4 standard always a device to carry on
multiple exchanges or conversations which contain data and/or control information
with another device at the same time across a single point-to-point link. The protocol is
not, however, a device control language. It does 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 operate over
IEEE1284.
Auto
o
An initial state is compatible interface and starts IEEE1284.4 communication
when the magic strings (1284.4 synchronous commands) are received.
On
o
An initial state is IEEE 1284.4 communication and data that received it by the time
it is able to take synchronization by magic string (1284.4 synchronous commands)
is discarded.
Off
o
An initial state is compatible interface and never starts IEEE1284.4
communication even if the magic strings (1284.4 synchronous commands) are
received.
For parallel I/F, regardless of the factory default setting, after initial ink charge
operation, the setting of the EEPROM must be 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
17