POSIFLEX Business Machines PP3000 manual Data Structure in Serial Interface, DTR Mode

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DATA STRUCTURE IN SERIAL INTERFACE

DTR Mode

This mode is accessed when the DIP switch 1-5 is ON. Signals are controlled using the DTR line as BUSY flag. If a printer errors do not occur after the power is turned on, the DTR signal line changes to “SPACE”. When the host computer confirms that the DTR signal line is set to “SPACE”, the host computer sends the data text via the RXD signal line to the printer. Also, the printer will set the DTR signal line to “MARK” when the empty space in the data buffer is below 256 bytes. After the host computer detects that the DTR signal line is at “MARK”, transmission of the data text is stopped. In this instance, data can still be received up until the data buffer becomes completely full. When the empty space in the data buffer is increased following printing (when the data in the data buffer is reduced to 256 bytes or less), the printer sets the DTR signal line to “SPACE”.

CHAP. 4

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Status

Bit position	Definition	Level
b0	Vertical parity error	1:error
b1	Framing error	1:error
b2	Mechanical error	1:error
b3	Paper empty	1:empty
b4	Constantly set at “0”	0
b5	Buffer empty	1:empty
b6	Buffer overflow	1:overflow
b7	Cash drawer open detection	switch is set to ON
	switch high level

Paper out

When the “paper out” detector senses the end of the paper, the printer stops printing after printing a maximum of two lines or on feeding the paper. Immediately after a “paper out” condition is detected, the printer sets to “OFF LINE” and the DTR changes to “MARK”. To reset the printer after a “paper

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