7.6

Table Of Contents

Emulation

The emulation defines how your document receives and processes its input data. It is basically a method with which Plan-

etPress Design will read the data and display it on screen. The way data selections are made and data pages are created

depends on the emulation, so it is always set at the beginning of your document creation, as you select your data file(s).

While you can have multiple sample data files in your document, all of them have to use the same emulation, since

data selections and data pages rely on the emulation to work properly.

Various emulation specific options can be set for most emulations, with the exception of the line printer and database emu-

lations. All emulations, except the database and XML emulations, also let you perform operations on the data to stabilize it,

such as add and remove characters or lines.

The sample data file you associate with the document, the emulation you select and the PPD you associate with the document

define how your document handles its input data, and consequently determine the accuracy of the output the document

produces with the data stream it receives at runtime. If you alter any of these settings, you should verify the change does not

compromise the output accuracy of the output.

This section explains what an emulation is, the different types of emulations available in PlanetPress Design, and how to fine-

tune the emulation to your input data.

Text-Based Emulation Properties

Text-Based emulations display your data in plain text in the data selector and the Data Pane, one line at a time, up to the limit

you specify in the emulation properties (by default, 66 lines). This is especially useful for legacy systems (such as AS/400

computers)that send data as text meant for older line printers using pre-printed forms. The emulation options are used to

make sure your data is stable.

Stabilizing data is the process of defining the size of the data page and where the first data page occurs in the data stream. A

stable data page is critical to obtain accurate results. When you stabilize your data, you also need to consider the internal struc-

ture of each data page. The internal structure of each data page must also be stable to make the data selections you use in

your document reliable. Ideally, a given piece of data occupies the same position across all data pages, or provides some sta-

ble characteristic that makes it possible to locate it on every data page.

The following properties are available for the text-based emulations (Line Printer, ASCII, Channel Skip and CSV) to help sta-

bilize the data:

l Add/remove characters: Enter the number of characters to add to, or remove from, the head of the data stream,

or use the spin buttons to increment or decrement the value. Positive values add characters while negative values

remove characters. Further note that if you remove characters in a CSV emulation, you should ensure that you do not

inadvertently remove field or text delimiters.

l Add/remove lines: Enter the number of lines to add to, or remove from, the head of the data stream, or use the spin

buttons to increment or decrement the value. Positive values add lines while negative values remove lines.

l Lines per page: Enter the number of lines each data page contains, or use the spin buttons to increment or dec-

rement the value. A higher value means more lines will be displayed on each data page. Note that increasing the value

for this setting increases the amount of RAM used by the application and may exceed the system’s capacity. Since

the Show used cells option also uses up some RAM, consider removing this option (see "Data Selector Display Pref-

erences" (page 79)) to reduce system load.