Tabor Electronics Ltd. - OED

3-19-1-2. Manual Trigger
The [TRIGGER] button simulates an external signal.
When the generator is set to trigger on an external
source, each time the [TRIGGER] button is pressed a
single output waveform is generated. The [TRIGGER]
button has no effect in continuous mode of operation
or when the instrument is set to internal trigger mode.
3-19-2. Gated Mode
Model 8024 is set to operate in gated mode when the
GATED light above the [MODE] button is lit. The
output remains at 0 V dc level as long as the TRIG
IN connector on the rear panel remains disconnected.
A TTL level signal can be used to stimulate the TRIG
input. The generator is sensitive to the rising edge only.
So, the first positive going transition at the TRIG IN
connector enables the generator output. The second
positive going transition disables the generator output.
At the end of the output cycle, the output goes back
to 0 V dc level.
3-19-2-1. Manual Gate
The [TRIGGER] button simulates an external gating
signal. When the generator is set to gated mode, output
waveforms are generated as long the the [TRIGGER]
button is pressed.
3-19-3. Burst Mode
Model 8024 is set to operate in burst mode when the
BURST light above the [MODE] button is lit. The output
remains at 0 V dc level as long as the TRIG IN
connector on the rear panel is not connected. A TTL
level signal can be used to stimulate the TRIG input.
The generator is sensitive to the rising edge only. So,
every time that a positive transition occurs at the trigger
input, the model 8024 generates one burst of output
waveforms at the output connector. At the end of the
burst output cycle, the output goes back to 0 V dc
level. The number of complete output waveforms which
will be generated can be programmed from 1 to 32767.
The counted burst mode of operation operates
equally on standard waveform and arbitrary waveform.
This mode can not work in conjunction with sequenced
waveforms. To eliminate confusion, the model 8024
does not allow you to go into burst mode if you selected
SEQ waveforms. Likewise, it will also not allow you
to go into burst mode if you are already generating
sequenced waveforms.
When you first select the burst mode, the display
shows the following reading:
BURST 00001
SOURCE EXT
This reading indicates that the generator is ready
to accept external signals at the TRIG IN connector
to stimulate its output. In this mode, the model 8024
responds to a rear panel signal, to a front panel [TRIG-
GER] button press, and to GPIB trigger commands.
The last two options will be discussed later in this
manual.
3-19-3-1. Internal Burst
When an external source is not available, the operator
has an option to use the built-in trigger generator. The
internal trigger generator is a free running generator,
asynchronous to the main output generator. The period
of the internal trigger generator can be programmed
from 20 μs to 999 s. When the internal trigger source
is selected the TRIG IN connector is disconnected, so
external signals do not effect the generator. To place
the model 8024 in internal trigger mode and to program
an internal trigger period rotate the dial in the above
shown menu. The menu will change as follows:
BURST 00001
SOURCE INT
Press the cursor control down button one to move
one menu layer and adjust the internal burst period as
explained in paragraph 3-19-1-1.
3-20. Using The Offset
Operating Instructions
The function generator employs three level windows;
allowing amplitude and offset to be independently selected
within these levels. When setting up the offset
parameter, one must keep in mind that the offset is
attenuated with the signal. The user has no control
over the selected internal amplitude range. This may
cause some confusion since, not knowing this fact, one
may produce an offset error at an amplitude-offset combination
that seems to be reasonable. It is therefore
suggested to first set up the amplitude parameter and
only then set the required offset level. An attempt to
modify the offset parameter beyond the capability of
the instrument will generate an error indication. Offsets
and amplitudes are independently selectable within the
level windows given in Table 1-1.
3-13