280 Series Waveform Generators

The 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.