Printronix ANSI Printer - Manual (Page 65)

Clearing The EVFU Memory
65
NOTE: The ESC code cannot be used simultaneously as the EVFU VT code
and the Special Function Control Code (SFCC). If ESC is used as the
SFCC, the EVFU must be used with the PI line enabled and set high.
Refer to the appropriate LinePrinter Plus, PGL, and VGL
Programmer’s Reference Manual for more information on the SFCC.
Clearing The EVFU Memory
The following actions will reset (clear) the EVFU memory:
1. Sending only the start load code.
2. Sending a start load code followed immediately by an end load code.
3. A second start load code is received, resulting in reinitialization of the
EVFU. (This allows the host data to be restarted.)
When the EVFU memory is cleared, the forms length returns to the previously
set value and the current print position becomes the top-of-form (TOF).
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 enabled and set high;
2. Data bit 5 must be 1 (set); and
3. The EVFU must be the selected Vertical Format Unit.
The Slew Relative configuration and the status of data bits 1-4 determine the
number of lines slewed as described in Table 21. (Note that the state of data
bit 5 is the difference between line slewing and using the interface lines as
EVFU channel codes.) As long as the EVFU is selected, this type of vertical
paper motion will occur regardless of whether the EVFU memory is loaded or
not.
If the Double High for One Line attribute is active, n + 1 lines will be slewed
rather than n lines.
1F 31 US 0 0 0 1 1 1 1 1 End Load
(X = Undefined, 0, or 1) (1 = High) (0 = Low)
Table 20. P-Series EVFU Codes - PI Line Disabled or Not Used
ASCII Data Bits
Channel
Hex Dec. Code 8 7 6 5 4 3 2 1