Epson Stylus Pro 7000 Series, Service Manual, Page: 31 / 231

EPSON Stylus Pro 7000 Revision B
Product Description Interfaces 31
1.2.7 Interface Selection
The SP 7000 has one slot for an optional Type-B interface and two built-in
interfaces; the USB and parallel interfaces.
The printer has only two internal BUS lines for the interfaces, so the parallel
and USB interfaces share one line while the other line is exclusive to the
Type-B interface. The USB interface takes priority when both interfaces are
connected meaning the USB interface works but the parallel does not. Make
sure nothing is connected to the USB interface before printing via the parallel
interface.
The parallel or USB interface can operate normally even if an optional Type-B
interface is installed and connected. The interface in use can be selected
automatically or manually.
„
Manual selection
The interface can be manually determined using the Printer Setting
Menu; see SelecType in the user’s guide for details.
The choices are INTERFACE = PARA/USB or INTERFACE = OPTION.
„
Automatic selection
If the interface setting is set to “AUTO” (default), the printer scans the
interfaces for incoming data. The interface that receives data first is
selected.
As long as the host sends data or the printer interface is in the busy state,
the interface selection does not change.
When the host stops transferring data and the printer is in the stand-by
state for a certain period of time, the printer returns to the idle state.
„
Interface status and selection
When the option interface is selected, the parallel/USB interface goes into
the busy state. The LH signal is “L” at this time. “L” means the power is
cut, in other words 1284 does not respond. Therefore, the LH check is
required via the Reverse channel. The USB interface responds NACK and
cannot receive data.
The the option interface is not selected, an off-line bit is set to Main Status
Register (MNSTS). When the printer initializes or returns to the idle state,
the USB interface is out of the NACK condition and resets the off-line bit
of the Main Status Register to option interface.
Be aware that an interrupt signal such as the -INIT signal only takes effect
on the parallel interface when the parallel interface is selected.
When the printer is initialized or returns to an idle state, the parallel
interface enters a ready condition, the serial DTR signal is set to low, and
the off-line bit of the Main Status Register (MNSTS) is reset.
The /INIT signal on the parallel interface is not active while that interface
is in Nibble or ECP Mode, or is not selected.