WinGPIB – Using the USER Tab

1. Introduction

The USER tab lets you build your own instrument control panel inside WinGPIB, without writing any code. The panel is described by a plain-text configuration file that defines the layout (buttons, readouts, charts, switches and so on) and what each control does. When you load the file, the controls appear on the USER tab immediately and are ready to talk to your instrument.

Typically you use one configuration file per instrument, although a single file can control both Dev1 and Dev2 at once. Because it is just a text file, you can edit it in any text editor, or in the editor built into WinGPIB, and a layout can be tweaked and re-loaded in seconds. Beyond simple buttons and displays the USER tab also supports calculated values, live statistics, charts, automatic actions (triggers) and Lua scripting, all with full GPIB/SCPI communication.

The USER tab requires WinGPIB V4.088 or later. A number of ready-made example configurations and the full PDF guide (WinGPIB_User_Tab_INSTRUCTIONS.pdf) are included in the \WinGPIBdata\Devices folder.

2. Basic Operation

Along the top of the USER tab are seven buttons. The order I recommend is:

Loading a file

1. Connect your instrument(s) on the DEVICES tab as usual.
2. On the USER tab press Load Config. and choose a config file, for example one of the supplied demos.
3. The panel is built. Press Run to start communicating.

Editing a file

Press Edit Config. to open the editor. It has:

• Syntax highlighting for block headers, parameters and comments.
• Line numbers, and a clickable Blocks list down the side to jump around large files.
• Auto-indent and smart Enter behaviour.
• Right-click tools such as duplicate line, cut/copy/paste and Save.
• Ctrl+S to save, Ctrl+F to find (with F3 / Shift+F3 to step through matches).
• A Save & Refresh button, which saves the file and reloads it onto the USER tab in one step – the quickest way to try a change.

When a file loads, WinGPIB checks it for common mistakes (for example missing semicolons) and tells you if something needs fixing.

Config file basics

• Each control starts with a keyword (BUTTON, SLIDER, RADIO, …) followed by a semicolon.
• Settings are written as key=value; pairs, one per line, indented by 3 spaces. A line that starts with whitespace is treated as a continuation of the control above it, so the indent matters.
• Parameters can be in any order, and optional ones can be left out.
• x and y set a control's position (and w / h its size) in pixels inside the User panel.
• Lines beginning with ; are comments. Comments at the end of a line use a double semicolon ;;. Blank lines are ignored.
• GpibEngineDev1=native; / GpibEngineDev2=native; select WinGPIB's standard engine, which keeps all its built-in device handling (terminators, device-specific cleaning and so on). standalone sends commands exactly as written with no extra processing. If omitted, native is used.

A very small example – a read button, a big display and an auto-refresh checkbox for a DMM on Dev1:

DATASOURCE;
   name=Q_ReadDMM;
   device=dev1;
   command=READ?;
   result=YourDMM;

BIGTEXT;
   name=YourDMM;
   x=20;
   y=35;
   f=32;
   w=400;
   h=50;

BUTTON;
   caption=READ;
   action=QUERY;
   device=dev1;
   command=READ?;
   result=YourDMM;
   x=20;
   y=100;
   w=120;
   h=30;

CHECKBOX;
   name=YourDMM;
   caption=Auto 0.5s:;
   func=FuncAuto;
   param=0.5;
   x=160;
   y=105;

The key idea is the result name (YourDMM above). Anything that produces a reading (a DATASOURCE or a QUERY button) writes to a named result, and any display control that uses the same name – BIGTEXT, CHART, STATSPANEL, HISTORYGRID, LED – updates automatically.

3. Commands & Controls

Setup and structure

Controls that send commands

Controls that show results

Controls that change behaviour

Button actions

Set with action= in a BUTTON entry.

A button with no action, just a result= name, is used with INVISIBILITY to show and hide controls.

Trigger actions

Used in a TRIGGER’s then= (or do=). Chain several with the | character.

Conditions can use stats:Panel.mean / std / min / max / pkpk / count / ppm, num:TextBoxName, bignum:BigTextName, any result name or an LED name, with the comparisons > < >= <= == !=. A trigger fires when its condition changes from false to true; need= sets how many consecutive checks must pass first.

Matching the panel to the instrument – determine=

RADIO, DROPDOWN, SLIDER, SPINNER, TOGGLE, TOGGLEDUAL and MULTIBUTTON can read the instrument’s current setting when the config is loaded, so the controls start out showing what the instrument is really set to. The form is determine=query|expected|resptext (text match) or determine=query|expected (numeric match). No commands that change the instrument are sent while doing this.

Lua scripting

For anything more elaborate, you can run Lua scripts, either typed into a TEXTAREA on the USER tab or stored in the config file between LUASCRIPTBEGIN;name=MyScript and LUASCRIPTEND and run with a RUNLUA button. The devices are called "dev1" and "dev2" in scripts. Lua scripts need the native engine.

There is also a built-in set of maths and metrology helpers for calibration and linearity work:

Example: five readings from a Lua script

LUASCRIPTBEGIN;name=FiveReads
for i = 1, 5 do
   local r = query("dev1", ":READ?")
   settext("BigTextLua", r)
   logto("LuaLog", "Reading " .. i .. " = " .. r)
   doui()
   sleep(1000)
end
LUASCRIPTEND

BUTTON;
   caption=Run Lua;
   action=RUNLUA;
   command=FiveReads;
   x=20;
   y=170;
   w=180;
   h=30;

4. Where to Go Next

The best way to learn is to load one of the demo configurations from the \WinGPIBdata\Devices folder, press Edit Config., change a few values and use Save & Refresh to see the result. The full reference, with every parameter and many more examples, is in the User Guide PDF (the User Guide button).

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