Lets start from an empty screen, like the one you see just after starting the Waveform

Generator program (if you have already started to draw, use FILE->NEW to clean up). Point somewhere in the A pane, press the mouse button and keep it pressed down. You see a vertical line at the click point and the horizontal one between the beginning of the screen and the click-point. As you move the mouse up and down, the line marking the pulse amplitude moves within the maximum levels. There is another horizontal line in the upper part of the window showing the superposition of this pulse with the corresponding pulse in the B pane. Release the mouse button and the first pulse will be drawn:

The width of your newly created pulse corresponds to the X-coordinate of the click-point. You may change it by dragging the pulse-boundary marker on the time axis, as shown in the next figure (PC-Windows only: you may also click with the right mouse button on the pulse amplitude).

The broken vertical lines show the pulse width you are changing. The solid vertical line, which follow the cursor movements denotes the new position of the end of the pulse. You cannot move it more left than the beginning of the pulse, since a negative time would not make sense. The minimum width allowed is 2 units. You can move this vertical line almost as far right as you like - the screen will auto-scroll to make you more space. If you really drag it far you might encounter another limit at 32000 units, which is the maximum pulse width allowed by the generator hardware.

Click now in the B-pane, to the right of the pulse end. You will create a new pulse there. Observe that the red frame surrounding the letter A has now jumped to B. This symbol tells you which of the two waveforms is “active” (it is important if you, for example, want to copy the current selection of pulses - you take them from the active waveform). Try now to draw a screen like this:

The last click created the pulse number 4 in the A-pane. The current selection is shown by an animated pattern (called “marching ants”) on the Mac and a grey box in Windows.

Remember: if you click on the existing pulse, you will change its amplitude. If you click to the right of the last pulse, you will create a new one. You know also that if you drag the pulse- boundary marker you will change the width. Try now to drag such marker with the “option” key pressed. Notice a change in the cursor shape! You are now moving the boundary between two pulses.(see fig. on the next page)

If you are not happy with the new width or amplitude of the pulse - just select “Undo” from the “Edit”-menu (or type cmd-Z). The text in the menu changes and always tells you what you can undo, which usually is the last editing action. (A few commands cannot be undone in such an easy way. The most “dangerous” ones will warn you before proceeding.) Most often you will like to create pulses of equal length. You may fix the desired width of all new pulses by using the menu PULSE->SET NEW PULSE WIDTH… (or type cmd-W). You will see a dialog asking you to type the desired (integer!) value. If you feel that you need a similar help with drawing the amplitudes, use menu VIEW->SET GRID->EQUAL STEPS…(or type cmd-Y). The default values are 20 in both cases. Let’s draw some steps:

Of course, you may prefer just to write the amplitude and length values for each pulse. Use menu PULSE->SET VALUES… or type cmd-A, and the following dialog window will appear:

The default button is drawn with a thicker line and responds to the “Enter” and “Return” keys in all dialogs in the Waveform Generator program. The default button of the dialog above moves you to the right on the time axis. If you are at the last pulse (as in the picture above) it reads “New”, because it will create a new pulse for you. Otherwise it tells “Next” as opposed to the “Previous” button. Use TAB or shift-TAB to jump between the edit-fields. The “Cancel” button, which responds also to the “Escape” key, allows you to leave the dialog without making any change (this is also true for all dialogs in the Waveform Generator program). Click on “Done” button when you are ready. If you wonder what the “control bit” is: there is an output marked “C-BIT” on the front panel of each channel, if you click on the “control bit” check-box here, a logical “one” level will be generated from that output during this pulse.

You do not have to type everything by hand. There is a number of quite powerful editing commands for your assistance. As in nearly all programs there is an “Edit” menu, which has a copy, cut, paste and duplicate functions. Let’s try to use these simple commands now. And remember the rule: you always copy from, or paste into, the active waveform.

Let’s make a simple exercise. Select last 4 pulses in the A-waveform - point with the mouse on the first of them in the superposition pane, press the mouse button and drag to the right. The “marching ants” pattern will show the selection. (There are two other ways to make a selection - read the description of the PULSE menu). Choose EDIT->COPY or press cmd-C. Click on the B-letter (or anywhere to the left from Y-axis of the B-waveform) to select the B-waveform. Pressing a down-arrow key would also select the B-waveform. Choose EDIT->PASTE or press cmd-V. Your screen might now look like this:

OK, that was simple. But there is a snag in it: the copy always contains both the information about amplitudes and about the timing. Since we pasted the selection at the same place, only in the other waveform, there was no problem because there was no difference in timing. If we now paste our 4 pulses over the pulses from1 to 4, the widths of pulses in the copy and waveform differs, and we must decide what to keep. The default setting (as you start the program) is to override without asking both the existing amplitude and the existing timing.(Do not worry: the paste command can be undone). You may choose to override only the amplitude or only the timing or to be asked each time - call PREFERENCES… dialog from the EDIT menu to do this. With the default settings you would get:

Try now the INVERT SELECTION command (from EDIT menu, or press cmd-5/ctrl-F5). It will invert amplitudes of all pulses within the selection. Go back to A-waveform and try INVERT WAVEFORM command (cmd-6/ctrl-F6). If you wish to insert a pulse before the selection, use INSERT PULSE command (cmd-I) or if you need many pulses, call N*INSERT… instead.

The screen might look now like this:

The DUPLICATE command (cmd-D) copies the selected pulses and pastes them just after the selection.

So far, we have been drawing amplitudes and widths in arbitrary units. The scale is, as you can see on the screen, ±100 amplitude unites. Thus, the superposition is in the range of ±200 units. The resolution of the screen within A- and B-pane is ±50 pixels. So, if you drag the amplitude you get only even values. Press option key to access the odd values.

In the picture above 100 units correspond to 10 volts, as you can see in the maximum amplitude control panel. Click on an arrow symbol to increase or decrease this value in 1V steps or 0.1V steps if you press an option key. You can also click on the digital display and type a new value directly (in a dialog which will come up). If you now click on the pop-up menu (the rectangle with a shadow), you may change “units” to “volts” and the superposition waveform will be calculated according to max amplitude values for both waveforms (note the color change).

In the timing control you have more possibilities. You can read the pulse width in units, μs or ms. Not all the choices are available at the same time. They depend on the choice of the time-base clock, which you select using the TIMING menu.

Please notice the small symbol between the up and down arrows above the time-display. Normally it resembles a waveform. If you click on it, it changes to a symbol presenting a width of one pulse.

This symbol tells you what will change when you click on one of the arrows or the digital display. In the case as above, when one-pulse width symbol is shown, you will change the width of the selected pulse only (or the first pulse of the selection, like the pulse #5 in this example) and you will not alter other pulses. Let’s change it to 40 μs:

In the other case, when the waveform symbol is shown, you will scale the entire timing.

Let’s try it. Click on the mode symbol or use the menu TIMING->SCALE TIMING. The symbol changes. Click on the digital display. The dialog comes up (Mac only, in Windows you may edit the displayed text directly). The message in the dialog explains what you are about to do. Type 20 and press Enter key (or click on OK button if you like). We are changed the width of the pulse number five from 40 μs to 20 μs and at the same time we changed the widths of all other pulse by multiplying them by one half (20/40=0.5). The result you can see on the next figure.

If you think that the picture is too dense now, use a “Zoom” function from the “View” menu. You can zoom in or out in the ratio of 2 each time, but there is no limit on the zoom level. You might prefer to use the keyboard shortcuts: command + to zoom in, command - to zoom out and command 0 (zero) to return to the 1:1 scale.

And after zoom-in twice:

Please notice, that the display has scrolled to make the selected pulse number 5 well visible. Before proceeding to the next chapter, scroll it back to the first pulse by using the scroll bar or the menu GOTO->START or by pressing command-left cursor.