Appendixes

Interfaces

Parallel port status signals when an error occurs

Under the specifications for this bi-directional parallel interface, the parallel port status signals when an error occurs are, as shown below, partially processed differently than with compatible mode used up till now. When both are on in the setting menu, even if a printer error has occurred, the BUSY signal line is not active (“H”).

Error

Change in the status of a signal line

 

 

 

 

Both directions OFF

Both directions ON

 

 

 

 

 

Paper end

Busy

: L ￿ H

Busy

: L ￿ unchanged

 

PError

: L ￿ H

PError

: L ￿ H

 

Select

: H ￿ L

Select

: H ￿ unchanged

 

nFault

: H ￿ L

nFault

: H ￿ L

 

 

 

 

 

Error other than paper end

Busy

: L ￿ H

Busy

: L ￿ unchanged

• Head open

PError

: L ￿ unchanged

PError

: L ￿ unchanged

• Other

Select

: H ￿ L

Select

: H ￿ unchanged

 

nFault

: H ￿ L

nFault

: H ￿ L

 

 

 

Conditions for Busy

• Receive buffer full

• Receive buffer full

 

• Data being read

• Data being read

 

• Error

 

 

 

 

 

 

 

 

Compatible timing specification

[When power is on] (Time it goes off-line)

PowerOn

Reset

BUSY

*ACK

SELECT

[While receiving data]

Data0-7

*Strobe

BUSY

0.5∝s 0.5∝s 0.5∝s

Note: Busy rises when *Strobe signal starts, and data is latched with *Strobe

signal starts.

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