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281, 282, and 284 Waveform Generators use Direct Digital Synthesis
techniques as well as variable clock sampling technology to provide a fully
featured programmable function and arbitrary waveform capability. The 281,
282 and 284 are 40 MS/s arbitrary waveforom generators with one, two, and
four channels, respectively.
Waveform Manager Plus Software
provides all the features needed for creation, manipulation and management
of arbitrary waveforms within a single Windows-based program.
Single or multiple channels:
The 28x series comprises a
single channel model (281), two channel (282) and 4 channel (284). Each
channel can be operated fully independently, or multiple channels can be
linked using simple or complex relationships.
Waveforms
Standard waveforms include:
sine, square, triangle, dc, positive ramp, negative ramp, sine(x)/x, pulse,
pulse train, cosine, haversine and havercosine. Output frequency range is
0.1 mHz to 16 MHz for sine and square and up to 100 kHz for triangle, ramps
and sine(x)/x. Rise time for pulse is < 25 ns with a period range of 100 ns
to 100 s. Output amplitude range can be adjusted from 2.5 mV to 10 V pk-pk
into 50 Ω.
Versatile pulse generator
capabilities:
Each channel can generate not just pulses but
complex pulse trains. A pattern of up to 10 pulses can be quickly defined
with each pulse having its own amplitude, width and delay. The whole pulse
train pattern can then be replayed at a user defined repetition rate. Where
variable rise time pulses are required, the full arbitrary function can be
used.
Arbitrary capability unmatched
at this price:
The 280 series are highly sophisticated 12-bit
arbitrary generators capable of recreating virtually any waveform. True
variable clock architecture is used with clock speeds between 0.1Hz and 40
MHz. This architecture avoids the clock jitter associated with DDS arbitrary
generators and permits waveform linking, looping and sequencing. Waveforms
may be defined with up to 4096 vertical points and from 4 to 65,536
horizontal points. Arbitrary waveforms may be replayed at a specified
waveform frequency, period or sample rate. Up to 100 user-defined waveforms
can be stored within the instrument’s 256K of nonvolatile memory.
Linked-sequence operation:
Up to sixteen arbitrary
waveforms may be linked in a sequence. Each waveform can have a loop count
of up to 32,768 and the whole sequence can be run continuously or repeated
more than a million times. For multi-channel models, waveforms on different
channels can be ‘daisy chained’ and looped. By summing the channel outputs,
up to 64 segments can be used to create highly complex waveforms.
Multi-channel phase locking:
Any number of channels can
be phase locked with offsets defined to a resolution of 0.1 degree (or 360
degrees/waveform points for arbitrary waveforms). For applications requiring
more than four channels, multiple generators can be phase locked. The 280
series also has the facility for phase locking to another generator.
Multi-channel Summing:
Waveform Summing sums the waveform from any
channel into the next channel. Alternatively any number of channels can be
summed with an external signal. This permits complex modulations to be
created such as noise superimposition.
Inter-channel triggering and
modulation:
Because any channel can be
triggered by the previous or next channel, waveforms on different channels
can be ‘daisy chained’ and looped. By summing the channel outputs, up to 64
segments can be used (32 segments for 282). A channel can be used to AM
modulate or SCM modulate another channel.
Wide frequency sweep range:
All waveforms can be swept
over their full frequency range at a rate variable between 30 milliseconds
and 15 minutes. Sweep can be linear or logarithmic, single or continuous.
Single sweeps can be triggered from the front panel, the trigger input, or
the digital interfaces. Multiple channels can be swept simultaneously.
Amplitude modulation:
Amplitude Modulation and Suppressed Carrier
Modulation are available for all waveforms. Any channel can be used to
modulate another channel. Alternatively all channels can be modulated
simultaneously via the modulation input.
Built-in trigger generator:
All waveforms are available
as a triggered burst whereby each trigger edge will produce one burst of the
carrier. Start and stop phase is fully variable. Both Triggered and Gated
modes can be operated from the internal trigger generator, from an adjacent
channel, an external source or a key press or remote command. The trigger
generator signal is available as a separate output if required.
Tone switching:
The 280 series can provide triggered switching
between up to 16 frequencies of standard or arbitrary waveforms. Tone
switching modes can be gated, triggered or FSK using any trigger source. By
summing two channels together it is possible to generate precise DTMF test
signals.
Windows based waveform editing:
Each generator is supplied complete with
sophisticated Windows based software for the creation, editing and
management of waveforms. This powerful software can be used to create
arbitrary waveforms from scratch using drawing tools, equations or both
together. Real-world waveforms imported from DSOs or other sources can be
modified and combined with other waveforms using editing functions. A
library of ‘standard’ waveforms is included which can be used as ‘elements’
when creating or modifying waveforms. A powerful Equation Editor provides an
array of mathematical functions including logarithmic and geometric
operands. Waveform creation and editing can make use of drawing tools in
combination with equations, insertion and manipulation. Multiple waveforms
can be further combined using mathematical operators to create new
waveforms.
Import from DSOs and other
instruments:
The Windows software
incorporates direct support for uploading waveforms from Tektronix digital
oscilloscopes. A driver for LabWindows CVI from National Instruments is
available which enables imports from other equipment to be achieved within
the LabWindows environment.
Fully programmable:
via RS-232 or GPIB The 280
series incorporates both an RS-232 interface and a GPIB (IEEE-488) interface
as standard. These can be used for loading arbitrary waveforms and for
remote control of all instrument functions.
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