Arbitrary - Metrix GX1010 Notice De Fonctionnement

The staircase edit menu is shown above. Up to 16 steps can be defined (numbered 00 to
15) with a length and level specified either in absolute terms or as a percentage of full
scale height and cycle length. When the value is set to ABSolute in the VALS field the
LENGTH field will accept numbers in the range 0000 to 1024 (the cycle sample length) and
the LEVEL field will accept values in the range -512 to +511, i.e. 10-bit resolution peak-
peak; -512 and +511 correspond to -10V and +10V peaks respectively with the amplitude
on the Main menu set to maximum but note that the actual peak-peak voltage will be
determined by the actual amplitude setting. When the value is set to %MAX in the VALS
field both the length and level fields will accept numbers in the range 0 to 100% in 1%
steps.
To edit the staircase, or create a new one, proceed as follows. Move the cursor to the
STEP field and use the keyboard or rotary control to select the first step to be changed;
note that the level of the selected step is dithered during editing to provide a visual check
that the correct step is being changed. Move the cursor to the LENGTH field and use the
keyboard or rotary control to enter the new length for that step in the appropriate units;
press CONFIRM to enter the value. If the AUTO field has been left set at YES (the default
value) the cursor will automatically move to the LEVEL field; enter a value in the
appropriate units and press CONFIRM again. The cursor will move back to the LENGTH
field and the STEP field will be incremented by 1 ready for the next entry. If AUTO has
been set to NO, the stepping between LENGTH and LEVEL and the incrementing of the
STEP must be done manually.
The staircase waveform is made up from steps 00, 01, 02 ... etc., in numeric order, up to
the step whose length brings the total to 1024 or more samples; all these steps, including
any in the sequence that have zero length, will be flagged as ACTIVE beside their step
number in the display because changing the LENGTH or LEVEL of any of them will affect
the waveform. Those steps beyond the last active step will be flagged INACTIVE, even if
they have a non-zero length, because changing them will not affect the waveform. If the
length of the last active step takes the total number of samples above 1024 then the
surplus samples are ignored (but the full length is displayed); if the last active sample has
insufficient samples to bring the total to 1024 then the end of the waveform is filled in with
the necessary number of samples at LEVEL=000.
Waveform editing forces the symmetry to 50% to simplify entry; when edit mode is ended
the waveform symmetry will return to that specified on the Main menu.

4.7.2. Arbitrary

Up to 5 user-defined arbitrary waveforms can be down-loaded via the RS232 or GPIB
interfaces and stored, together with a 16-character name in non-volatile RAM; these
waveforms occupy stores 01 to 05 inclusive. Stores 06 onwards contain a number of
frequently used arbitrary waveforms stored in ROM; these may be changed or added to
from time to time in response to user requirements.
Each arbitrary waveform is stored as 1024 points each with a value in the range -512 to
+511, i.e. 10-bit vertical resolution; -512 and +511 correspond to -10V and +10V peaks
respectively with amplitude on the Main menu set to maximum. However, the actual
waveform 'played back' from the generator can have its amplitude, offset and symmetry
adjusted as if it was a basic sine, square, etc., waveform.
The currently recalled arbitrary waveform is selected by pressing the ARB key; the lamp
beside the ARB key lights to show that arbitrary mode is selected. The ARB edit menu is
used to change the currently recalled arbitrary waveform, to store new waveforms in non-
volatile RAM and to name them. The arbitrary edit menu is accessed by pressing the blue
30 - II
VALS=ABS AUTO=YES
STEP=00 ACTIVE
LENGTH=0256
LEVEL=+511
GX1010