Printronix P3000 Series manual Clearing the Dvfu Memory, Dvfu Channel Instruction

Table 5–5. DVFU Channel Instruction

	ASCII						Data Bits					Channel
Hex	Dec	Code	PI	8	7	6	5	4	3	2	1
00	0	NUL	1	X	X	X	0	0	0	0	0	1
01	1	SOH	1	X	X	X	0	0	0	0	1	2
02	2	STX	1	X	X	X	0	0	0	1	0	3
03	3	ETX	1	X	X	X	0	0	0	1	1	4
04	4	EOT	1	X	X	X	0	0	1	0	0	5
05	5	ENQ	1	X	X	X	0	0	1	0	1	6
06	6	ACK	1	X	X	X	0	0	1	1	0	7
07	7	BEL	1	X	X	X	0	0	1	1	1	8
08	8	BS	1	X	X	X 0 1 0 0 0						9
09	9	HT	1	X	X	X 0 1 0 0 1						10
0A	10	LF	1	X	X	X 0 1 0 1 0						11
0B	11	VT	1	X	X	X 0 1 0 1 1						12
X = Undefined, 0 or 1						1 = High						0 = Low

Clearing the DVFU Memory

Following one of these actions resets (clears) the DVFU memory.

•Sending only the start load and end load codes (no channel assignment data).

•Sending an odd number of DVFU characters (channel assignment data). (The printer de- tects the characters after it receives the end load code.) Remember, two data bytes are re- quired per line.

•Sending a second start load code, which reinitializes the DVFU. (This restarts the host data)

•Sending the first byte (after the start load) that does not specify top–of–form.

The DVFU data is ignored if the DVFU has not been selected from the control panel. Deselecting the DVFU returns the forms length to the previously set value and the current print position becomes the top–of–form.

Relative Line Slewing

Another method of moving paper using the PI line results in vertical slews of a specified number of lines within the form relative to the current print line (rather than slewing to a specific line). For this to occur, three criteria must be met:

1.The PI line must be set high;

2.Data bit 5 must be 1 (set); and

3.The DVFU must be the selected Vertical Format Unit.

Vertical Format Units 5–9