Plotter Tab


This virtual HP-IL device emulates a HP7470A plotter.

HP-IL configuration:

Accessory ID0x60
Default Address5
Device IDHP7470A

This virtual HP-IL device emulates a HP7470A plotter. All HP-GL commands of the HP7470A plotter (HP-IL version) are supported. In addition the HP-GL commands AA, AR and CI are supported which were only available on the RS232C version of the HP7470A.

Note:The plotter tab requires the program emu7470 which is part of version 1.7.7 or later of the LIFUTILS. The default configuration of pyILPER does not contain a plotter tab. You have to add this device in the Virtual HP-IL device configuration.

The paper size settings in the pyILPER configuration controls the papsersize setting of the plotter as well as the page size of the PDF output.

Device controls

The plotter tab has the following controls:

  • Pens button: allows to assign pen configurations to pen 1 and pen 2.
  • Enter button: register a digitized coordinate.
  • P1/P2 button: display or alter the scaling points of the plotter.
  • Clear button: clears the plotter view and initializes plotter. If the GUI is in digitizing mode, the digitizing mode is cancelled.
  • PDF button: Create a PDF file from the current plotter view.
  • Status button: Monitor the status byte and error information of the plotter
  • Device enabled checkbox: If checked, the virtual HP7470A is available and can be used as HP-IL device. The HP-IL loop must always be reconfigured after activation or deactivation.
  • Log Plotter checkbox: Activates logging the HP-GL commands and the status and response of the device to the file Devicename.log in the pyILPER working directory. Output is always appended to that file. A time stamp in the file marks the start and the end of each logging. The log file is closed automatically on program termination.

A yellow error led indicates a HPGL-Error. Use the status button to obtain information about the error code and additional diagnostics. If the error led is red then the external plotter emulator program emu7470 could not be started or had crashed.

Tab configuration menu

  • Log buffering: enable or disable buffering of the log file. If log buffering is off the log file output is flushed to disk after an end of line was encountered. This enables watching the log file output but may decrease the execution speed of pyILPER considerably.
  • Log level: the extent of logging can be configured here.


Digitizing is initiated by a HP-GL DI command. This puts the GUI into digitizing mode. A cross-hair cursor appears and you can digitize coordinates. The Enter button registers the coordinates of the last clicked location. They are now available for the HP-GL OD command.

The Clear button cancels digitizing mode. No coordinate is registered.

In digitizing mode the coordinates of the clicked locations are shown at the right side of the tab. In addition numeric values of the coordinates can be entered as well.

Display or alter locations of scaling points

The location of both scaling points are displayed and the GUI enters digitizing mode (see above). You may digitize now a new position for P1. Register the location of P1 with the ENTER button and digitize the location of P2. After registration of P2 the digitizing mode is finished and the new positions of the scaling points are applied. The digitizing mode can be cancelled with the Clear button at any time.


The plotter emulator should provide reasonable results for proper HP-GL commands. A compatible behavior in error conditions needs improvements.