Technote 10116 - Why Can't I Plot Correctly From KEYCREATOR

Version/Module: KEYCREATOR

Platform: Windows 2000/XT

Date: 7/6/2004   revision 1

Summary

Plotting in the Windows environment is a topic that causes confusion for new and experienced KEYCREATOR users alike.  The subject is especially difficult for users moving from a DOS plotting environment to Windows.  This is compounded by confusion over different driver types and their setup.  The most common complaint is that the plotter does not produce line widths like the DOS versions of KEYCREATOR did.  This technote helps address these issues.

Definitions

First, a few terms that will be used need to be defined:

Palette: not quite the kind an artist uses, but a collection of elements used to display or plot geometry.  Modern plotters use palettes of virtual pens to plot different line characteristics.

Raster: printing by means of scanning or moving a print head across a printing medium in successive passes.  Raster is also the process used in electrostatic or laser printing by scanning the image to be printed onto a charged photosensitive drum.

Vector: plotting by moving a pen and the paper in a movement defined by start and end points of the geometry to be plotted. 

Plotter Types

The types of devices used to produce printed output from programs such as KEYCREATOR fall into two classes: true vector based plotters such as the CalComp DesignMate or the HP Draftmaster, or raster-based designs such as the HP DesignJet or the Encad NovaJet. 

Vector-based designs use a movable carriage, or pen holder, and one or more pens.  The combination of a pen and back and forth paper movement across a platen is used to draw the plot on the paper.  In these types, the physical characteristics of the pen, such as color and tip width, determine the line that will be drawn.  These plotters often have a carousel to hold other pens. 

Raster-based designs are not plotters in the classic sense.  They are really printers that use electrostatic or inkjet technologies to produce the printed image much like conventional laser or inkjet printers.  These types do not have physical pens.  Instead, they produce patterns of dots, or pixels, on the paper to form the plot.  Thus, they can be used as printers or plotters, depending on the driver selection.  Since they do not have actual pens to produce line widths, they rely on a user- or software-defined internal palette of virtual pens.  How this palette is set up depends on the plotter.  Early HP DesignJet models such as the 450 use a setup sheet generated by the plotter.  The user defines settings and line width by making selections on the setup sheet and feeding the sheet back into the plotter to be read into the hardware memory.  Other plotters such as the HP DesignJet 750 use control panel menu selections to define hardware settings such as the pen palette.  Consult the plotter manual for the method of setup for your plotter.

Driver Types

For the KEYCREATOR user, the raster-based plotters cause the most confusion.  Pen plotters use a vector driver based on a plotter language such as HP-GL, HP-GL/2, or a manufacturer variant of one of these languages such as American/Western Graphtec GPGL or Houston Instruments DMPL.  Raster-based plotters can use either a vector plotter driver based on HP-GL/2 or a raster printer driver.  The driver choice determines how the plotter and KEYCREATOR will be set up.  However, the user often has trouble determining which type of driver is being used for the plotter.  Part of the confusion can stem from the manufacturer labeling of drivers.  For example, a user can download a generic HP-GL/2 plotter driver from the HP Web site.  However, the same Web site identifies the printer drivers for the DesignJet series of plotters as HP-GL/2 drivers.  Although based on the HP-GL/2 language, they are used as printer drivers in Windows.  The issue is further complicated by the fact that more than one driver can be used with a plotter in Windows.  Windows also allows users to easily change the name of installed drivers in the Printers applet in Control Panel.  Unless drivers are clearly identified, they can easily be confused. 

What Kind of Driver Am I Using?

Fortunately for the KEYCREATOR user, driver identification is not difficult.  To identify the driver type, load KEYCREATOR and open a part file.  Click on File > Print/Plot… to open the printing dialogs.  Select a driver for the plotter in the first box and click OK.  In the second box, look in the lower right corner.  There are two fields labeled “Print Mode” and “Plot Mode”.  One of these fields will be grayed out and one will be active.  If Plot Mode is active and Print Mode is grayed out, a vector plotter driver is being used.  If Print Mode is active and Plot Mode is grayed out, a raster or printer driver is being used. 

Raster Plotting

Now that we can identify the plotter driver types, we can look at how they are used with KEYCREATOR.  The settings that influence the appearance of prints and plots are found under the Tools > Options > Print/Plot tab>Modify Configuration.  We will look at raster printing first.  Under the Print/Plot tab, several areas control this type of printing:

·         Entity Color map of the KEYCREATOR entity color palette.  These are the on-screen colors that the KEYCREATOR geometry is created in.

·         Width scale settings that control the printed line thickness for each entity color.

·         Color selection that determines the final printed color for each entity color.

·         Color Mode selection boxes that control the default print mode for the selected printer.  The choices are screen color and black, set by pen number and set by color number.

In KEYCREATOR, geometry can be created with eight different line weights as well as different colors.  However, high-resolution printers may not produce a print that correctly represents the displayed line weight used in the part file.  The Line Width selections are used to allow thicker lines to be printed for each entity color, pen number or no scale.  The line thickness can be controlled for any one entity color or all colors.  The range of adjustment is from zero to two.  Most users find that 0.25 to 0.35 will produce satisfactory prints.  The essential point here is that the line thickness on paper is being controlled by the Print/Plot line thickness setting when used with a raster-type driver.

Vector Drivers

The following section discusses plotting with vector drivers.  The setup of these drivers is important to successful plotting with KEYCREATOR.  Technote 10100 discusses the setup of HP-GL/2 drivers.  The rest of this technote will assume that such a driver has been installed and set up.

If plotting is done with a vector-type driver, line thickness on paper is controlled by other factors.  In this situation, the definition of pens in the plotter and the plotter driver now controls the appearance of the printed output.  The Line Thickness settings under Tools > Options > Print\Plot>Modify Configuration>Width scale tab have no effect with vector drivers.  The Print/Plot tab has three settings for controlling plotting:

·         Entity color

·         Pen Number

·         Plot Pen Map

The KEYCREATOR Plot Pen Map should agree with the pen map color selection that has been set up in the plotter driver.  A maximum of eight pens can be defined in the KEYCREATOR pen map.  A Plot Pen Number is assigned to each entity color in the Entity Color list.  Normally, the KEYCREATOR defaults should be used

We'll look at plotting by pen number first. 

Plotting by Pen Number

Either during or after the part file creation, KEYCREATOR allows the user to assign a pen number attribute to the file entities.  When the file is plotted, this pen number attribute is converted to the corresponding color from the KEYCREATOR Pen Color Map.  This color is sent to the plotter driver for conversion to a pen number.  The resulting pen number is sent to the plotter to tell it which pen from the palette or carousel to use to draw each entity in the file.  This means that the appearance of geometry in the part file has no bearing on the printed output.  Pen number attributes are independent of geometry color or line weight.  These attributes are coming from the plotter pens.  KEYCREATOR is only indicating which pen to use. 

Plotting by Entity Color

Plotting by entity color is a different process.  In this plot mode, entity color attributes are used to determine the pen number that will be used to plot the geometry.  When a part file is plotted in this mode, the color of the geometry from the screen color or by color number in the Tools > Options Print/Plot>Modify Configuration>Color tab is translated to the assigned pen number in the Plot Pen Number selection list.  The Plot Pen Number is converted to the corresponding color from the Pen Map.  This color information is sent to the driver.  The color map in the driver converts the color sent by KEYCREATOR to a pen number that is sent to the plotter.  The line thickness and color attributes of the plot are still determined by the pens in a plotter pen carousel or an internal palette.  However, entity color was used to select the plotter pen, not an entity pen attribute.  This means that part file geometry can be color-coded for the plotted line thickness without regard for entity attributes.

For either of these plot modes to work correctly, both KEYCREATOR and the driver must be set up properly.  This means that the KEYCREATOR and driver pen maps have to be set to the same colors, and the geometry entity colors/ or color numbers must be assigned to the proper pens under the Tools > Options > Print/Plot>Modify Configuration>Color tab.  If any of these three settings are incorrect, the plotting results will be unpredictable.  With so many variables, troubleshooting the source of the problem can be time consuming. 

Software Palettes

Some newer raster plotters can be set to use a software palette instead of an internally user-defined palette.  This means that the software determines the pen characteristics, not the internal plotter palette.  In this case, the software is the driver.  Some plotter drivers have settings for color and pen width, which are sent to the plotter.  To utilize this, the plotter must have a software palette setting in the hardware configuration.  Some plotters, such as later model HP DesignJets, support this feature.  The plotter hardware manual will have support information on this feature.  If the plotter can use it, this palette configuration can have advantages as well as disadvantages.  Some of the advantages are:

·         On-the-fly pen customization without changing confusing hardware menus.

·         Changes can be made at the workstation without having to access a remote plotter.

·         Each user in a large multi-seat environment is able to set pen color and width to their

requirements without interfering with workflow. 

Some of the disadvantages are:

·         The plotter hardware must support software palettes.  Not all plotters may support this.

·         Additional settings can cause confusion for inexperienced users.

·         Letting users in a large multi-seat environment set their own pen settings may compromise company standards.

·         Replacing or reinstalling the driver will necessitate replacing the pen width settings.  This is dependent upon recording the settings and being able to find them when needed.

*Generally, software palettes are not recommended with plotter drivers for most users in KEYCREATOR.  However, they can be a valuable tool for the users that understand how KEYCREATOR, the driver, and the plotter work together.  The decision to use software palettes should be evaluated on a case-by-case basis.  If third-party plotter drivers such as Winline are being used, it may require that software palettes be used in the plotter.  It is recommended to check with the driver vendor for plotter specific settings before loading the driver.

Recommendations

·         When installing drivers, clearly name them to identify the driver type. 

·         When setting up drivers, use the KEYCREATOR defaults in the Tools > Options > Print/Plot>Modify Configuration tabs as a starting point.  Make changes to the driver or the plotter before changing KEYCREATOR settings.

·         Use Plot by Entity Pen Number and hardware pen settings as a first choice for plotting line widths. 

·         Use software plotter palettes only if the advantages outweigh the disadvantages.

·         Document all settings once KEYCREATOR, the driver, and the plotter are setup.  Run a configuration or set up sheet from the plotter and keep it with the documentation.