1. PREPARATION STEPS

You are presented with a series of dialogs to define the steps in the “script”.

Step 1

State how many frames are to be generated during this step. By default this number is same as in the N*BURST command. The waveforms are generated as defined on the computer screen.

Step 2

In this dialog you have to state how the waveforms in each channels should be rolled (see ROLL WAVEFORM… command) before entering each consecutive step. The rolling is defined in terms of the number of pulses:

  • Negative numbers mean roll left;
  • Positive numbers mean roll right;
  • Zero means unchanged.

The number of pulses is relative to the previous state. Values in the fields corresponding to channels that are not present in the hardware have no effect.

The rolling refers to channels, not waveforms. Same waveform can be assigned to all channels, but each channel is then treated individually in the script.

In each row you have also to state how many frames are to be generated in the step.

Step 3

The script can be generated once or a 32-bit number of times. Please note the total number of steps in the script shown in this dialog equals one initial step plus the number of rows in the second dialog.

2. USING SCRIPT

Each time you press the RUN button (or ctrl-R) all waveforms will be reloaded and the execution of the script will start. It can be terminated by STOP button (ctrl-H).

The Script is a software-based extension to the normal mode of the waveform generator operation and has several important limitations. The two memory banks are no longer updated to hold the same data at all times. Alternatingly one memory bank is used for waveform generation, while the other memory bank is used to perform the waveform rolling in a background in order to prepare the generator for the next step in the script. In this way there is no delay between the steps.

Limitation: it is not possible to update waveform parameters, nor to move the trigger point, during execution of the script. Generally – issuing a command that causes a memory swap in the generator results in incorrect calculation of the waveform roll.
The frequency can be altered by using an external generator.