Grabs screenshot from a HP4395A (probally a 4396A will work also) Network/Spectrum/Impedance Analyzer through GPIB interface and the NI-488 drivers.
The binaries are here: HP4395A Screen Grabber binaries. Just download the HP4395A_Screen_Grabber_EXE.zip and unpack. Keep the exe and dll's together in a folder.
Then download the National Instruments drivers from here: NI-488. Install them with the default settings.
After the drivers are installed, start the main executable HP4395A_Screen_Grabber.exe.
Well, it makes a screenshot of the connected instrument by simply pressing the "Capture" button. The image is downloaded from the instrument via GPIB bus and than shown in the UI (See screenshot above). After download, the image is put on the Clipboard, so you can past it easily into your documentation. There is also an option to save the image as TIF,JPG,BMP or PNG.
With the combobox above the Capture button you can set the color mode of the image:
- Color on White background
- Color on Black background
- Black and White
But you can also change the color's of some items with the Color table. Just click on the color cell of the item you want to change and a color chooser will popup. Note that these color categories of the items are dictated by the instrument and I just have given them a name. This is not something that can be changes.
The lower pane is a log window where the program outputs it messages on what it is doing.
The code is loosly based on this codeproject project: Instrument Snapshot: How to Acquire and Render Screen-shots from Older Test Equipment I first tried this project, but I clouldn't get it to work. So i decided to make my own tool.
The screen grabbing works by utilizing the Save Graphics option of the instrument it self. It first saves the Graphics to a temp file on the memory Storage Device, then opens it for read and reads the data back.
This is roughlly the algorithm with GPIB commands that is used:
- PURG "TEMP1234_T"; *WAI // delete the old tempfile
- PRIC;PRICVARI // Set the color mode
- STODMEMO // Set the storage device to memory
- SAVDTIF "TEMP1234"; *WAI" // save Graphics to temp file
- ROPEN "TEMP1234_T"; *WAI" // open the temp file for read
- READ? // Read the data. Called sequential until no more data avalible