You can acquire your own HP-GL/2 .PLT files via the options on the Acquire menu, if your PC has a National Instruments-compatible GPIB interface or a Prologix USB-GPIB adapter. It's important to understand that there are two ways to do this in 7470.EXE. Unlike other plotter emulators, 7470.EXE supports both host-requested and device-initiated plotting operations.

Host-Requested Plots

A few instruments, currently limited to the following models, support "host-requested" plotting in 7470.EXE.

• Tektronix 49xP/275xP-series spectrum analyzers (except 492P and 496P)
• Tektronix 271x-series spectrum analyzers
• HP 8566A/8567A/8568A spectrum analyzers (see notes below)
• HP 8566B/8567B/8568B spectrum analyzers
• HP 8560A/B/E and 8590-series portable spectrum analyzers
• Tektronix 2430A, 2432A, and 2440A digital oscilloscopes
• Tektronix SCD-series transient digitizers (ROM version 1.5 or later)

If you have a National Instruments-compatible GPIB adapter, you'll normally issue host-initiated plot requests by selecting one of the "Request plot from supported device at address n" selections on the Acquire menu. Prologix GPIB adapter users should review the comments in SERIAL.INI carefully to learn how to configure the Toolkit applications for use with the available Prologix adapter versions. Note that earlier Prologix adapters, and those with their DIP switches set to Device mode, can't support host-requested plots at all.

Most instruments that support host-requested plots may be addressed directly on the 7470.EXE command line, just like a .PLT filename:

	7470 3

Host-Requested Plots via Instrument Menu Shortcuts

Beginning with the 1.80 release of 7470.EXE, you can also add strings of the form

	instrument_0         Tektronix 2430A at GPIB address 4\tF2

Important note for HP 8566A/8567A/8568A users

These analyzers can't be automatically identified and addressed by 7470.EXE, and they also don't support HP-GL/2 plotting. Never fear, though... 7470.EXE can still work with them. To acquire screenshots from an HP 8566A, 8567A, or 8568A, you must create an instrument menu shortcut to tell 7470.EXE you're accessing one of these spectrum analyzers.

In order to tell 7470.EXE to access one of these analyzers, the instrument name portion of the 7470.INI menu-shortcut entry must contain the string "8566A", "8567A", or "8568A". When the instrument name contains one of these model identifiers, 7470.EXE will request raw annotation, state, and trace data from the analyzer and generate its own HP-GL/2 .PLT file image based on it. This HP-GL/2 image may then be saved, rendered, and printed just like any other .PLT file. A typical menu shortcut for the -A suffix analyzers looks like this:

	instrument_0         HP 8566A / 8567A / 8568A (via HP-GL/2 emulation) at GPIB address 18\tF8

The normal host- or device-initiated plot menu options will not work with these instruments. If you use an older Prologix controller board, it will need to be upgraded to the version that supports software-selectable GPIB addressing.

The HP-GL/2 synthesis process takes place in less than a second, including the data acquisition itself. It's actually a great way to access the 8566B/8567B/8568B models as well; not only are 7470.EXE's synthesized HP-GL/2 plots much faster to acquire, but certain features such as markers look much better than they do in the B-series analyzers' own plots. Note, however, that a few features including the horizontal display-line cursor will not appear in a synthesized plot, nor will hardware diagnostic/error messages.

Device-Initiated Plots

If your instrument doesn't appear in the list above, that means it isn't directly supported by 7470.EXE, and won't work with the Acquire->Request functions, instrument menu shortcuts, or the command-line GPIB address feature. However, chances are good that you can still obtain plots from it by activating its front-panel "Plot" button while 7470.EXE is in the "Wait for device-initiated plot" mode. This mode may be selected from the Acquire menu, or by pressing the lower-case 'w' key.

GPIB Instrument and Interface Configuration Notes

Host-requested plotting requires 7470.EXE to carry on a two-way GPIB conversation with the instrument, so you'll need to configure your instrument for Talk/Listen mode (as opposed to Talk Only mode) for use with this feature. This typically involves changing a system-level menu option or DIP switch. All National Instruments GPIB adapters support host-requested plotting, but only versions 3.1 and later of the Prologix USB-GPIB adapter can provide the necessary GPIB-controller functionality. (For more information on the Prologix GPIB-USB board, you can email Prologix here.)

Device-initiated plotting usually requires the instrument to be configured for Talk-Only mode. When their front-panel PLOT buttons are pressed, some instruments, such as the HP analyzers, expect the plotter to be addressable at a specific GPIB address, usually 5. With National Instruments GPIB hardware, the emulated plotter address is controlled by 7470.EXE's GPIB menu; with a Prologix adapter in Device mode, the device address is a property of the DIP switch settings. Certain other instruments expect to be the only addressable instrument on the bus when their PLOT buttons are pressed, requiring selection of the "Listen only" option in 7470.EXE's GPIB menu, or address 0 on a Prologix board.

As you can imagine, experimentation is sometimes needed to find the right combination of device and host settings that will allow 7470.EXE to work with a particular instrument. Some notes on specific instruments appear below.

• Tektronix 49xP and 275xP spectrum analyzers
  • Device-initiated plots: Must be set to Talk-Only mode via DIP switch in rear. This may cause problems if other devices are on the GPIB bus. 7470 GPIB setting must be "No assigned plotter address (listen only)." Plot with front-panel PLOT button (typically Blue Shift-PLOT).
  • Host-requested plots (recommended): Both Talk-Only and Listen-Only switches should be off (0). LF-or-EOI switch does not matter for use with 7470.EXE, but should be set to on (1) for use with SSM.EXE and PN.EXE utilities.
  • DIP switches on these instruments are extremely prone to age-related failures. Verbum sat sapienti est.
• Tektronix 2430A / 2432A / 2440A DSOs
  • Device-initiated plots: DSO must be set to "Plotter" device mode. 7470 GPIB setting must be "No assigned plotter address (listen only)."
  • Host-requested plots (recommended): DSO must be set to T/L device mode. 7470 GPIB setting does not matter.
  • 7470.EXE will NOT work with the earlier non-A models, whicih do not support GPIB plotting at all.
• Tektronix SCD-series transient waveform digitizers
  • Device-initiated plots: Issued automatically after triggered acquisition is complete
  • Host-requested plots: Available on ROM versions 1.5 and later; earlier versions must use device-initiated plotting
• HP 8566B, 8567B, and 8568B spectrum analyzers
  • Device-initiated plots: 7470 must be configured via the GPIB menu or Prologix DIP switch (in device mode) to listen at address 5.
  • Press "Lower Left" button on front panel for device-initiated plotting.
  • Host-requested plots are also possible with these analyzers. For faster plotting, though, try the 8566A/8567A/8568A-series menu shortcut technique described above!
  • Other HP 8560- and 8590-series spectrum analyzers are reported as working like HP 8566B. Host-requested plots may work on these; if not, device-initiated plots should be possible.
• HP 8566A, 8567A, and 8568A spectrum analyzers
  • These do not support HP-GL/2 plots at all, either device-initiated or host-requested. See notes above on how to work around this limitation.
• Other instruments known to be compatible with 7470.EXE for device-initiated plotting
  • Tektronix TDS694C and related oscilloscopes
  • Tektronix TDS784D and related oscilloscopes
  • Tektronix SCD series transient digitizers

    Pre-V1.5 instruments do a screen dump immediately after acquisition

  • Advantest R3762AH vector network analyzer
  • Advantest R3361A spectrum analyzer
  • Advantest R4131B spectrum analyzer
  • Advantest R3261C spectrum analyzer
  • LeCroy 9354AM DSO
  • HP 3040A cable analyzer
  • HP 54201A DSO
  • HP 8510B vector network analyzer
  • HP 8752C vector network analyzer
  • HP 8757A scalar network analyzer
  • HP 8753A vector network analyzer
  • HP 3562A dynamic signal analyzer
  • HP 5372A frequency/time interval analyzer
  • HP 8569B spectrum analyzer

    7470 GPIB setting must be "No assigned plotter address (listen only)"

  • HP 4195A network/spectrum analyzer

    7470 GPIB setting must be "No assigned plotter address (listen only)"
    Use Copy->HP_IBDefine->Talk Only, then set Plot_mode and do Copy Start

Also, if you have more than two or three powered-down instruments on the GPIB bus, keep in mind that they'll load the bus, possibly preventing successful communication with the instrument(s) that are turned on. When attempting to use 7470.EXE with a new instrument for the first time, it's best to use a simple direct connection between the instrument and the host PC's GPIB adapter.

I'm always interested in hearing from users of other instruments so they may be added to the list above. Please feel free to contact me at [email protected] with any bug reports or success stories.

Menu Commands and Keyboard Shortcuts

Key               Menu Command                                 Remarks

l                 File->Load HP-GL/2 data                      Retrieves a saved HP-GL/2 file (.PLT, .HPG, .PGL, .HGL) for viewing

s                 File->Save image or HP-GL/2 data             Saves the currently-browsed plot as an HP-GL/2 file.  Also can be 
                                                               used to save the current window contents (which may consist of 
                                                               several overlaid HP-GL/2 files) as a .GIF, .BMP, .TGA, 
                                                               or .PCX image file

p                 File->Print image                            Sends the current window contents to the default Windows printer

Delete            File->Close current plot                     Stop displaying/browsing the currently-visible plot.  This command 
                                                               does not delete the file; it simply removes it from 
                                                               7470.EXE's current display list.

Ctrl-Delete       File->Delete current plot file               Same as File->Close current plot, except that it deletes the 
                                                               HP-GL/2 file being viewed  

Esc               File->Quit

Space or F5       View->Refresh current display                Reloads the currently-visible HP-GL/2 file.  If the file was 
                                                               acquired as a host-requested plot in the current 7470.EXE session,
                                                               it will be re-acquired.

b                 View->Browse sources one at a time           Allows you to use the +/- keys to move through the list of 
                                                               viewable plots, displaying them one at a time

o                 View->Overlay all sources                    Renders the graphical (i.e., non-text) portions of all loaded 
                                                               or acquired HP-GL/2 plots atop each other.  In Overlay mode, 
                                                               the +/- keys are used to determine which plot contributes 
                                                               text labels to the display.

                                                               The three traces in the example image at the top of this page 
                                                               were displayed with the View->Overlay command prior to being saved 
                                                               as a .GIF file.  (Use caution when closing or deleting a file in 
                                                               Overlay mode.  The visible text labels are the only way to tell 
                                                               which file will be closed or deleted!)

+                 View->Next source                            Navigates the list of visible HP-GL/2 plots.  Specific behavior is
-                 View->Previous source                        determined by the choice of Browse/Overlay mode (above).

5                 Display->512 x 384                           Adjusts the size of 7470.EXE's window.  Some crowded plots look much
                  Display->640 x 400                           better at higher resolutions, but 7470.EXE will render an undersampled
6                 Display->640 x 480                           image if you you select a window size that's too large for the current
8                 Display->800 x 600                           Windows desktop.  You can change the default window size in the 7470.INI
0                 Display->1024 x 768                          file (below.)
                   
a                 Display->Aspect correction on                Turn aspect correction on if Smith charts and other polar graphs appear
f                 Display->Aspect correction off               squashed.  Again, you can change the default setting in 7470.INI.

i                 Display->Alternate colors                    Useful for certain instruments such as the HP 8566/8568 analyzers 
                                                               whose graticule and trace colors appear inverted in 7470.EXE.  
                                                               (This option was added prior to the pen_colors array in 7470.INI, 
                                                               which can be a better place to address color-rendering problems.)

w                 Acquire->Wait for device-initiated plot      Enters a mode in which 7470.EXE waits for, and renders, HP-GL/2 
                                                               data that arrives after pressing the front-panel PLOT button on an 
                                                               instrument.  You can press any key to exit this mode and restore 
                                                               normal 7470.EXE operation.

W                 Acquire->Wait for device-initiated plot,     Same as above, except that each incoming plot is sent to the 
                  then print                                   default Windows printer.  If you set the auto_print_mode field in 
                                                               7470.INI to '1', 7470.EXE will enter this mode on startup, acting 
                                                               as an unattended HP-GL/2 print server.

                  Acquire->Request plot from supported         When one of these options is selected, 7470.EXE will attempt to
                  device at GPIB address N(1-30)               identify the instrument at the specified address and initiate a 
                                                               host-requested plotting operation.  This may entail sending 
                                                               commands to the instrument to turn on its graticule display, 
                                                               select HP-GL printing, and perform other setup tasks.  Undefined 
                                                               results may occur if the instrument does not appear in the list
                                                               under "Host-Requested Plots" above.

                  GPIB->No assigned plotter address            During device-initiated plots, some instruments may need to 
                  (listen-only)                                communicate with the (emulated) plotter, expecting to find it at a 
                                                               specific GPIB address.  Others may expect the plotter to be 
                  GPIB->Plotter addressable at N(0-30)         entirely transparent to the GPIB bus.  If you are using a National 
                                                               Instruments GPIB adapter, this menu allows you to specify the 
                                                               plotter's address, or assign it no address at all.  

                                                               When a Prologix GPIB-USB adapter is in use, this functionality 
                                                               is provided by its DIP switch, and the GPIB menu will have no 
                                                               effect.

7470.INI

The directory containing 7470.EXE should also contain a file called 7470.INI, which provides some configuration defaults that you can change if desired.

Most users won't need to edit this file. To configure the GPIB Toolkit for use with various versions of the Prologix GPIB adapter, you'll need to edit SERIAL.INI instead (see below).

Here is an example of a 7470.INI file with comments explaining each line:

;
;Initial X/Y resolution
;

res_x                640
res_y                480

;
;Set to '1' if Smith charts and other polar graphs appear squashed 
;

aspect_correction    0           

;
;Set to '1' to display graphs in an alternate color set. 
;Useful for the HP 8566B analyzer, possibly others 
;
;'0' causes 7470 to use the default pen colors specified below
;

color_scheme         0

;
;Specify a higher value (in milliseconds) if 7470.EXE times  
;out during device-initiated plotting                        
;

async_timeout        3500

;
;Options below are used to determine how the plotter responds to various  
;output queries.  No effect unless a valid GPIB board address is specified.
;Lines in this group may be commented out if necessary to suppress replies 
;to a given query
;

OE_reply             0
OH_reply             0,0,10000,7500
OI_reply             7470A
OP_reply             0,0,10000,7500
OO_reply             0,1,0,0,0,0,0,0
OF_reply             40,40

;
;Set to '0' to suppress replies to OS (Output Status) command
;

process_OS           1

;
;Set to '1' to autodetect pen-storage commands in device-initiated plots, 
;avoiding the need to wait for the async_timeout interval to expire at the
;end of each plot.  Set to '0' if plots appear to be terminated prematurely
;

SP0_detect           1

;
;Sets the default plotter address in the GPIB menu.  Use -1 for
;listen-only mode
;

default_board_addr   5

;
;For diagnostic/optimization purposes
;

async_xfer_size      100
async_GPIB_timeout   11
serial_read_timeout  500
release_sys_control  0
ignore_write_aborts  1

;
;Set to '1' to execute a 'W' (Acquire->Wait for device-initiated plot, then print)
;function automatically when 7470.EXE starts.  Helpful if you want to make an 
;unattended PC act as a dedicated HP-GL/2 print server
;

auto_print_mode      0

;
;Uncomment this line (remove the leading semicolon) to force
;7470.EXE to exit immediately after acquiring a plot and saving it.
;Normally, this line should be left commented out to run 7470 in its
;'interactive' mode.  Note that if any command-line parameters are 
;supplied when launching 7470, the auto_save_filename option is ignored
;

;auto_save_filename   c:\my documents\automatic capture.gif

;
;Optional list of instrument/address pairs for the Acquire menu
;
;Entries should have the form 'instrument_n    xxxx at GPIB address ',
;where n is an arbitrary value or name and xxxx is the name of the
;instrument at the specified address.  Optionally, the entry value may end
;in a '\tFn' substring to assign a keyboard shortcut to the instrument.
;(Don't use F1 or F5 - they are reserved by 7470 for other functions.)
;
;If any entries are present, then the Acquire menu will contain only those 
;entries.  They replace the list of generic "Request plot from supported 
;instrument" options.  As such, this feature is valid ONLY for those instruments
;for which 7470 supports host-requested plots!
;

;instrument_0         Tektronix 2430A at GPIB address 4\tF2
;instrument_1         Tektronix 494AP at GPIB address 3\tF4
;instrument_2         HP 8566B / 8567B / 8568B at GPIB address 18\tF6
;instrument_3         HP 8566A / 8567A / 8568A (via HP-GL/2 emulation) at GPIB address 18\tF8

;
;Pen RGB color array
;

pen_0                255,255,255 `White
pen_1                0,0,0       `Black
pen_2                0,0,255     `Blue
pen_3                0,192,0     `Green
pen_4                128,128,0   `Dark yellow
pen_5                255,0,0     `Red
pen_6                255,0,255   `Magenta
pen_7                0,255,255   `Cyan

GPIB Configuration and SERIAL.INI

The program directory should also contain a file called SERIAL.INI, which specifies the (real or virtual) RS-232 COM port settings for use with a serial GPIB adapter such as Prologix GPIB-USB boards.

To obtain host-requested plots with a Prologix adapter, the board must be configured for GPIB Controller mode, its address switches must match the instrument's GPIB address, and SERIAL.INI should be edited to set the controller_mode field to 1. To obtain device-initiated plots, it's usually a good idea to leave the Prologix board in Device mode with its DIP switches set to GPIB address 5. If you have an older Prologix board with no DIP switches, you will be limited to device-initiated plots. Either way, users of Prologix GPIB-USB and other serial adapters must edit SERIAL.INI to tell the GPIB Toolkit applications what COM port to use. See the comments in SERIAL.INI for more information.

If the COM port specification in SERIAL.INI is commented out with a leading semicolon - or if SERIAL.INI is missing entirely - all KE5FX GPIB Toolkit applications will attempt to use the National Instruments NI488.2 programming interface instead. This is the default configuration for most installations.

Note that some versions of Windows hide .INI file suffixes by default. In Windows 2000 and XP, for instance, SERIAL.INI may appear simply as "SERIAL," with the type "Configuration Settings." To turn off this behavior, go to the Tools->Folder Options->View tab in any Explorer window and deselect the "Hide file extensions for known file types" option.

Release Notes

Release 0.91 of 31-Oct-01

• Some formatting improvements and assorted updates, but still an alpha release!

• Takes multiple files or GPIB addresses to plot, overlay-style
• Runs at 800x600 by default
• Lets you print the current plot on any Windows-compatible printer by hitting 'p' (inkjets are great for this!)
• This release also includes source for my GPIBLIB wrapper for National Instruments NI488 drivers.

• Wildcards can now be used on the command line (e.g., 7470 ..\myfiles\*.plt)
• If wildcards are used, all matching files will be displayed one at a time. Use the + and - keys to navigate the file list. You may also run 7470 by itself to display all .PLT, .HPG, .HGL, and .PGL files in the current directory.
• Hit 's' to save the current plot as a 16-bit .TGA file. Many photo editors, including Microsoft's, will allow you to manipulate these files and convert them to other common formats such as .GIF, .BMP, or .JPG.

• Made some improvements to the GPIBLIB wrapper to support instruments like the HP5345 and HP5370 counters that use terminator characters to delimit transmitted strings.
• Added example "get current frequency" programs for these counters in their respective subdirectories.
• Sending a GPIB device-clear message is now optional behavior for GPIB_startup(), and disabled by default. This change was needed to avoid resetting the HP5370B counter during GPIB handshaking. It doesn't seem to have affected any other instruments.

• Beta release of the new and improved 7470.EXE: near-complete rewrite.
• All commands accessible via Windows menu
• Saves .GIF, .BMP, and .PCX files directly from program
• New "wait for plot" feature should (theoretically) support any instrument in talk-only mode
• Many UI improvements including resolution switching and overlay/browse modes

• Many improvements, including more supported instruments, better HP-GL rendering fidelity, 7470.INI setup options, and more

• Added response options for several plotter output-status queries, necessary to support HP 8752C VNA and many other instruments
• Added auto_save_filename, other options to 7470.INI
• Default suffix for saved files is now .PLT, not .GIF
• Revised handling of UC (User Character) opcodes

• Reduced buffer size used by GPIB_read() from 64K to 4K. This function can no longer be used to acquire a large block of data such as an entire plot.

• 7470.EXE is now installed with the larger KE5FX GPIB Toolkit package
• Improved character-positioning code in renderer
• Added support for host-requested plotting from Tektronix 2710-series spectrum analyzers
• Significant GPIBLIB rework to add support for Prologix GPIB-USB adapter
• Added instrument name/address/function-key feature to 7470.INI
• Added user-configurable RGB pen colors to 7470.INI
• Fixed a bug that could cause blank pages to be printed on a LaserJet
• Added HTML user guide

• Windows desktop no longer used as the working directory when running from a desktop icon
• Renderer now supports device-initiated plots from HP 3562A dynamic signal analyzer
  • HP-GL/2 OF and OO commands supported
  • SC command supports parameter-free form

• HP 8566A/8567A/8568A spectrum analyzers supported (via NI GPIB interfaces only)
  • Host-based HP-GL/2 synthesis used to create .PLT image from raw analyzer data
  • GPIBLIB updated to inhibit EOI assertion at end of host-transmitted strings
• Renderer now supports device-initiated plots from Advantest R3361A spectrum analyzer
  • Selected pen restored to its equivalent physical position after an SC command
  • Parameter-free SC command uses reasonable (nonzero) defaults

• Tektronix SCD-series transient digitizers supported

• HP 5372A time-interval analyzer supported

• Extensive changes made to simplify the code that handles generating and refreshing temporary .PLT files. (Most users will not notice any operational differences.)
• Added support for software-based GPIB address-selection feature in new Prologix adapter firmware
  • Moved controller_mode, device_addressable, and host_addressable fields from 7470.INI to SERIAL.INI. These options now apply to all applications in the GPIB Toolkit, not just 7470.EXE. If you want to keep your existing 7470.INI file when upgrading, you'll need to move these three options to SERIAL.INI yourself.
  • Added reset_to_local field to SERIAL.INI. This affects Prologix adapters only; see SERIAL.INI for more information
  • HP 8568A rev-B spectrum analyzer successfully tested with new software-addressable Prologix adapter

• HP 3588A spectrum analyzer supported
  • Negative ASCII characters rendered as spaces
• Rohde & Schwarz FSA spectrum analyzer supported

• Fix potential bug with device-initiated plots on the HP 8566B/8568B analyzers using Prologix/serial adapters
  • GPIB library ignores device_addressable and reset_to_local fields in SERIAL.INI if controller_mode is 0

• Don't check iberr after ibrd() or ibwrt() unless ibsta has ERR bit set (attempt to improve compatibility with NI GPIB-232CT-A)

• Always reset devices to local control at shutdown time when using NI-compatible GPIB interfaces

Acknowledgements and Additional Notes

My graphics library (WinVFX) doesn't support scalable/rotatable vector fonts. Consequently, text elements in plots will not appear exactly as they do when rendered by a LaserJet or HP-GL/2 plotter.

Thanks to Harrison Hooker, W8YMO for supplying information on the obsolete HP7470A command set.

Thanks to Vladan Temer of Sonoma Instrument Co. for supplying additional 7470A documentation and providing extensive assistance with support for various HP instruments in the 1.60 release.

If you find that 7470.EXE doesn't meet your needs, an excellent commercial alternative is PrintCapture. See the PrintCapture site for more information. Two more-expensive commercial packages from Aphena, which I haven't personally evaluated, are Plottergeist and SoftPlot.