Epson EPL-N1200 Reference Manual page 184

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 (nAutoFd)
high, this signal is set low in order to indicate that the transmission data is
ready.
reverse data transfer phase: This signal is set low in order to indicate 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 indicate that the bus
direction is from the printer to the host. This signal is set low to terminate
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.
HostLogicHigh
NC. (Not used.)
GND
Twisted pair return signal.
CG
Connected to the printer chassis. This signal and GND are connected.
+5V
Pull up to +5V with 1 k
Technical Specifications
A-11