nFault/nDataAvail/nPeriphRequest
Compatibility mode: Low signal indicates that an error occurred.
negotiation phase: This signal is set high in order to authorize 1284
compatibility. In nibble mode, after the host sets HostBusy (nA u t oFd )
high, this signal is set low in order to indicate that the transmissio n dat a is
ready.
reverse data transfer phase: This signal is set low in order t o ind icate to a
nibble mode host that the transmission data is ready. Afterwards, this
signal serves as nibble data bit 0 and then 4.
reverse idle phase: Indicates whether or not the data is valid.
ECP mode: This signal is set low to request communications with the host.
Valid in both forward and reverse direction.
nSelectln/IEEE1284active
Compatibility mode: Always low.
negotiation phase: This signal is set high at the same time that HostBusy is
low in order to request 1284 mode.
reverse data transfer phase: This signal is set high to indica te that the bu s
direction is from the printer to the host. This signal is set low to termi nate
1284 mode, setting the bus direction from the host to the printer.
reverse idle phase: Same as reverse data transfer phase.
ECP mode: Always high. This signal is set low to terminate ECP mode
and return to compatibility mode.
GND
Twisted pair return signal.
CG
Connected to the printer chassis. This signal and GND are connected.
+5V
Pull up to +5V with 1 kΩ
LKtwk Rev.C
A5 size Appendix A
97/12/26 pass 0
A-10 Technical Specifications