Driver for the Xerox XPRESS Plotter

The plot utility xpress_plot

xpress_plot is a utility program that communicates with the XPRESS plotter via the scsi interface. It is has utility functions that include:

    Obtaining the status of the XPRESS plotter
    Generating XPRESS test prints
    Sending monochrome and color test plots

The primary job of xpress_plot is to convert RTL files into a data stream required by the XPRESS and to perform the required handshaking needed to control the plotter.

Control Functions

express_plot enables the user to:

  • select a specific paper roll or

  • select a roll automatically based on image width.

  • Set the print quality to any of the 12 different quality modes that the Express supports.

  • Specify a maximum wait time for access to the XPRESS
        (up to 30 minutes in the event that some other process is using the XPRESS.)

    Data Flow

    xpress_plot is able to read RTL files from stdin. This enables it to integrate with the Unix lp process. All messages generated by xpress_plot are output to stderr.

    Device Driver

    To actually connect to the EXPRESS plotter via the SCSI port a device driver must be installed on the plot server than handles the low level communication. As a new GDSPLOT user you will be faced with one of two situations:

      1. The EXPRESS plotter is already in service using other applications. Therefore a device driver is already installed and your task will be to identify it so that the xpress_plot program can use it.

      2. The EXPRESS plotter is not already used with some other application and hence no device driver is installed for it. Your task then will be to install the driver correctly so that express_plot can use it.

    Case 1 - Device Driver Already in Place

    Device drivers are normally located in the directory /dev. You must be able to identify the desired device file; it is probably a link to something in the /devices tree. If you issue the command:

              # ls -l /dev

    one of the lines you see should be an entry that looks like the following:

              lrwxrwxrwx   1 root  other  93 Oct 15 21:28 

          /dev/xpress0 ->   

          /devices/iommu@0,10000000/sbus@0,10001000/espdma@5,8400000/esp@5,8800000/xpress@5,0:character

    The above line has been broken to improve readability. Issuing the command:

              ls -lL /dev/xpress0

    will result in:

              crw-rw-rw-   1 root     sys       82,  0 Nov  1 15:27 /dev/xpress0

    Notice that the file permissions shown allow any user to read and write to the XPRESS plotter driver. If you want to run the xpress_plot program as a normal user, you must make sure that the correct permissions are in place. If not, you might get an error message like:

              error: permission denied

    when attempting to execute xpress_plot. It appears that when kernel drivers are initially installed the default permission is rw-r--r-- and since the driver is owned by root, other users will not be able to access it.

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