Table of Contents
Advertisement
Line Spacing - The printer can use 6 or 8 lpi spacing with the EVFU and DAVFU.
VFU's calculate the forms length by line density selected. The 6 and 8 lpi spacing may be
mixed on the same form, but should be done carefully.
DAVFU
The DAVFU may be selected in the P-Series protocol mode and is generally used when
the Dataproducts interface is selected. A maximum of 12 channels can be assigned to
each physical line of a form for up to 143 lines. The user assigns channel numbers to each
line on the form. Channel codes are then sent by the host computer to the printer result
ing in rapid paper slewing to the next corresponding line. The programming sequence is:
Start Load code, channel assignments, and End Load code.
Start Load Code - 6C, 6D, or 6E Hex
The DAVFU Start Load code of 6E (hex) with the Paper Instruction line (PI) high initi
ates the DAVFU memory load routine. Alternately, the Start Load code 6C (hex) may be
used in place of 6E (hex). In this case, the line spacing will be set to 6 lpi. Similarly, if the
Start Load code 6D (hex) is used, the line spacing will be set to 8 lpi. In the case of code 6E
(hex), the line spacing is not changed.
Channel Assignment
Following the Start Load code, all data bytes received are interpreted as channel assign
ment data until the End Load code is received. The current line corresponds to the first
line in the DAVFU, and the first line is the top of form and must have Channel 1 set, or
the entire load sequence is ignored. The last channel 12 loaded is assigned as Bottom of
Form (BOF) If skip-over perforation is enabled, slewing will occur from BOF to TOF.
A maximum of 12 channels can be assigned to one physical line on the form. Two eight-
bit data bytes (DAVFU characters) are required per line. As shown in Table 5-1, the
least significant 6 bits of the first data byte are used to assign channels 1 through 6; the
least significant 6 bits of the second data byte are used to assign channels 7 through 12. If
a bit is set, the corresponding channel is assigned.
Each line on the form requires two bytes. For lines not requiring a channel identification,
the two bytes should not contain channel assignments.
This procedure can be continued for a maximum of 143 lines (286 DAVFU bytes). The
DAVFU ignores anything more than 286 bytes until the End Load code is received; if 572
bytes are received without an End Load code, the End Load code is forced" and the
load routine is terminated.
End Load Code - 6F Hex
The DAVFU End Load code is 6F (hex) with the PI line high. This terminates the
DAVFU memory load routine, and if enabled via the control panel, the VFU LOADED
indicator lights on the control panel.
5-2
P9012 Vertical Format Units
Advertisement
Table of Contents
