•Extensibility request The printer responds tothe extensibilityrequest in theaffirmative, when
therequest is 00 H or 04 H,which means:
00 H Request nibblemode of reverse channel transfer.
04 H Request device ID innibble mode of reversechannel transfer.
•Device ID Refer to thefollowing descriptions:
ESC/P [00 H][31 H] .......... MFG: EPSON,CMD: ESC/P9-84,MDL: FX-2170, CLS: PRINTER
IBM 2381 Plus [00 H][32 H] .......... MGF: EPSON,CMD: PRPII9-01, MDL: FX-2170, CLS:PRINTER
1.3.2.3 Interface Selection
The printerhas 2interfaces: theparallel interface andType Boptional interface. These interfaces areselected
manually indefault settingmode or selected automatically.
Manual selection
One of 2 interfacescan beselected in default settingmode.
Automatic selection
Automatic interface is enabled in default setting mode. In automatic interface mode, the printer is initialized
to the idle state, where it scans which interface is to be activated. The interface that receives data first is
selected. When the host stops data transfer, and the printer is in standby for a number of seconds specified in
default setting mode, the printer returns to the idle state. As long as the host sends data or the printer interface
is busy, theselected interface remains active.
Interface state and interface selection
When the parallel interface is not selected, that interface goes into a busy state. When the Type B serial
interface card is installed and it is not selected, the interface sends an XOFF code and sets the DTR signal to
MARK. When the optional interface is not selected, the printer sends disable commands to the optional
interface. When the printer is initialized or returned to the idle state, the parallel interface goes into the ready
state, the serial interface sends an XON code and sets the DTR signal to SPACE, and the printer sends an
enable command to the optional interface. Remember that interrupt signals, such as the INIT signal on the
parallel interface,are noteffective unless that interfaceis selected.
1.3.2.4 Prevention Hosts fromData Transfer Time-out
Generally, hosts abandon data transfer to peripherals when the peripheral is in the busy state for dozens of
seconds continuously. To prevent hosts from this kind of time-out, the printer receives data very slowly,
several bytes per minute, even if the printer is in the busy state. Thisslowdown is started when the rest of the
input buffer becomes several hundreds of bytes. Finally, when the input buffer is full, the printer is in busy
continuously.
Product Description FX-2170 Service Manual
1-24 Rev.A