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 final 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.

nSelectIn/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.

GND

Twisted pair return signal.

CG

Connected to the printer chassis. This signal and GND are connected.

+5V

Pull up to + 5 V with 1 kΩ .

A-10Technical Specifications