G-View - FAQs

Is there a way to quickly load a group of Gerber files so that they can be viewed in the same window?

First launch the viewer if it is not already running.

Next at your desktop group select all of the files you wish to be simultaneously viewed in the same window. In the Lite mode you are limited to two(2) film layers and 32 in the Pro mode.

Drag this selected group on top of the GView Icon on your desktop and the system will pass this group of files to the Viewing application were the files will be decoded into individual layers and then displayed in the same window.

The file has loaded but I don't see anything?

The most likely cause is that the file you loaded did not contain any valid Aperture definitions. 274X format files contain a Format and Aperture Definition at the head of each file. The older 274D format documents only carry the plotting commands.

If you have one of these older format documents you must enter the aperture data manually before GView will be able to display the file. Once you have manually keyed in the aperture list you can save that list for use with other older format Gerber files which use the same aperture list specification.

What are the limits of G-View in Lite-Mode?

The Gerber viewer will load Gerber plot files up to approximately 60KBytes in size. This will allow you to view most modest designs. Gerber layers which incorporate Nomenclature or Silk information tend to be the largest and usually encounter the load limit. The Lite mode is also limited to two film layers. If you need to view more layers simultaneously or larger designs you will have to upgrade to the Pro-Mode.

When I try to load a file I get "Un-supported.." errors. What are these and what do I do about them?

G-View supports the basic core command set of the Gerber plotting language. There are a number of other commands that are used for image tiling options. These are normally only used by the photofabicators and thus are not normally found in most CAD outputs. Should you encounter these Gerber commands simply deleting them from the file will usually allow you to load and view the file.

If you are unable to resolve the issue, you can send the file to tech support and we will try to resolve it for you.

What types of files are normally loaded into G-View?

Gerber Plot language format files. These are actually ASCII text based file which use the Gerber Command structure. These files will usually have ".grb" ,".gbr" or ".txt" extensions. While these filename extensions are the most typical they are not the only ones in use. A few CAD design systems use ".pho" for photo layer. If you encounter a file using a ".pho" extension you can change the extension to the normal extension and then it will load into G-View if it is a proper Gerber plot file.

How do I edit a Gerber document?

Gerber documents are ASCII text documents. You can use a simple text editor to edit the files. Should you use an editor such as MS Word, be sure to save the file as text only when you are done.

What is M02 ?

This is the stop reading command found usually at the end of every Gerber Plot file. There should only be one of these and only at the end. If you are splicing Gerber Files together be sure to remove any of the extra M02 commands!

Is a Format Statement always necessary?

To insure proper reproduction in 274X Gerber a Format Statement properly defined is essential. G-View will make a guess by using default values to decode Gerber Documents. If the resulting image does not look correct then you can try different values in the setup panel and re-import the file.

I have a Gerber file but it doesn't appear to have the normal 274x header. How do I view this file?

This may be a 274D format file where the aperture data was separate. If you have the aperture information you can manually key that information into the Aperture Panel in GView. If you don't have any information then the only option is to guess at what the definitions might have been and then view the file. Experiment by changing the shape and values until the image looks correct.

Once the image looks correct save the Aperture table so that you do not have to key it in manually in the future when you wish to view the file again.

What is the "IR" command?

"IR" Gerber command specifies image rotation. GView will only plot at the drawings original rotation and thus disregards the IR command.

I converted some gerber files into PCB-ST documents. They Closely match the Gerbers but they do not seem to be 100% complete. Why is this?

In converting from Gerber to PCB-ST one can not expect 100% error free migration. This is because different design systems use different approaches for producing the Gerber. If you view a problem file in a number of different viewers you will see numerous differences.

Converting standard photo plot images usually pose few problems. However Ground planes can be troublesome depending upon how they were created in the Gerber structure. GView does a reasonable job in getting most of it migrated. The rest has to be manually corrected. This is regrettable but to be expected.