Printronix P3000 Series manual Chapter Vertical Format Units, General VFU Programming

CHAPTER 5

VERTICAL FORMAT UNITS

Introduction

The P3000 Series printers includes two vertical format units: Printronix standard Electronic Vertical Format Unit (EVFU) and Dataproducts Direct Access Vertical Format Unit (DVFU). 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 verti- cal tabs feature is always enabled in Serial Matrix protocol. This chapter describes:

•	General VFU Programming	. Page 5–1
•	P–Series EVFU	. Page 5–2
•	DVFU	. Page 5–7
• Serial Matrix Vertical Formatting		Page 5–10

General VFU Programming

A VFU 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, disable the VFU option 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 Paper Instruction (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 VFU:

Elongated Characters – Elongated (double high) characters can be used within VFU programs. The VFU automatically counts one line of elongated characters as two normal character 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 se- quence 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. Line spacing may be mixed on the same form; however, do so with caution to avoid unpredictable results.

VFU Deselected – If any VFU is deselected from the control panel, the VFU data is ignored and the forms length definition returns to the previously set value. The current print position becomes the top– of–form.

Vertical Format Units 5–1