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PERATOR
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ANUAL
WRXi-OM-E Rev B
201
Int
Cint (A) calculates the integer value next below A, which can be any acceptable VBS number.
Int (-7.4) = -8.
Log
Log (A) calculates the natural logarithm (to base e), of any acceptable VBS number greater than
zero. A negative number or zero will create an error.
To calculate Log
10
(A), use Log
10
(A) = Log(A) / Log(10)
Mod
A Mod (B) calculates the modulus of A, which is the remainder after A has been divided by B.
34 Mod 8 = 2. 34 Mod 55 = 0. -34 Mod 13 = -8. 21 Mod -8 = 5.
Randomize
Calculates a new seed for the pseudo-random number generator.
Randomize Timer uses the real-time clock for this purpose.
Sin
Sin (A) calculates the sine of any integer or real number, giving an output that is never greater
than +1 or less than -1.
Sqr
Sqr (A) calculates the square root of any integer or a real number that is not negative. If A is
negative, an error will occur.
Timer
Time since the previous midnight in whole seconds.
Hints and Tips for VBScripting
Set the trigger to Single or Stopped if you need to do a lot of editing: it is faster.
Before starting a script, remove any existing scripts that you do not need. This is because errors in an existing
script will give you error messages, even if your current script is perfect. And an existing good script may develop
a fault if you change the setup. For example, you might change the vertical scale or the memory length and get an
overflow if you did not guard against it in the script.
When starting a script, make sure that you have chosen the right kind: function or parameter. You can get some
very frustrating problems if you are in the wrong mode. You can cut and paste the VBS statements if you discover
this error.
If your calculation requires a long memory, development might be quicker if you test the principles on a shorter
trace at first.
Note that the pseudo-random number generator is reset at the start of a script. If you want a different set of
pseudo-randoms every time, put Randomize Timer in the program, to be run once, before any pseudo-randoms
are generated. You can use this instruction to re-seed the generator at any time during execution.
Do not put the final statement in a loop, hoping that you can see a progressive result as some parameter
changes. No output will be seen on the screen of the instrument until the script has been completely run and
quitted, so only the final result will appear. If the loop runs many times, you will think that the oscilloscope has
hung up.
If you want a For loop, end it with "Next" and not "Next X".
If you make a script that takes a long time to run, go back to the default setup before quitting or powering down, or
you will have a long wait next time you power up.
Always use a recursive calculation when this will speed things up.
Keep everything outside a loop that does not have to be inside, to speed things up.
Make your scripts clear, not only by indenting and commenting, but by structuring neatly as well.
Sometimes it might be easier to develop your script in Excel VBA (remembering that VBA is not identical to VBS),
so that you can display intermediate results. If you do this, note that you can read from a cell or write to it using
statements like these:
A = Worksheets("Sheet1").Cells(Row, Column).Value
Worksheets("Sheet1").Cells(Row, Column).Value = B
