Printronix P9000 Series - Manual (Page 81)

5-1 Vertical Format Units
CHAPTER 5
VERTICAL FORMAT UNITS
Introduction
The P9012 printer includes four vertical format units: 1) Printronix standard Electronic Vertical
Format Unit (EVFU), 2) Dataproducts Direct Access Vertical Format Unit (DVFU), 3) Direct
Access Vertical Format Unit (NVFU), and 4) Centronics Direct Access Vertical Format Unit
(CVFU). Although not a true" VFU, a vertical tab table is provided for forms control in Serial
Matrix protocol. All VFUs are available only in P-Series protocol and are enabled from the
control panel, and the Serial Matrix vertical tabs feature is always enabled in Serial Matrix proĆ
tocol. This chapter describes:
n General VFU Programming n NVFU
n EVFU n CVFU
n DVFU n Serial Matrix Vertical Formatting
General VFU Programming
A vertical format unit provides an efficient way to slew paper rapidly during repetitive printing
tasks. The type of VFU used is a configuration option selected from the control panel. If not
used, the VFU option should be disabled from the control panel.
The general VFU programming procedure is as follows:
1. Design a form, determining spacing and channel assignments for each line.
2. Send the programming sequence to the host. The sequence depends on the type of VFU
used.
Some VFUs require the PI line normally associated with the Dataproducts parallel interface.
Note that data bit 8 of the standard RS-232 interface can be configured for use as the PI line.
The following information applies when programming and using a Vertical Format Unit:
Elongated Characters - Elongated (double high) characters can be used within VFU proĆ
grams. The VFU automatically counts one line of elongated characters as two normal characĆ
ter lines.
Paper Runaway Protection - If the VFU is selected but not loaded when a VFU command is
sent from the host computer, the printer will move the paper a single line feed. If the VFU is
selected and the memory has been loaded, a channel code sent from the host, which is not a part
of the assigned sequence currently in memory, will move the paper a single line feed.
Line Spacing - The printer can use any line spacing with the VFU. The VFU determines the
forms length according to the program specifications and the currently selected line spacing.