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 Softwareprovides all the features needed for creation, manipulation andmanagement of arbitrary waveforms within a single Windows-basedprogram.
Single or multiplechannels:
The 28x series comprises a singlechannel model (281), two channel (282) and 4 channel (284). Eachchannel can be operated fully independently, or multiple channelscan 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. Outputfrequency range is 0.1 mHz to 16 MHz for sine and square and up to100 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 amplituderange can be adjusted from 2.5 mV to 10 V pk-pk into 50 Ω.
Versatile pulse generatorcapabilities:
Each channel can generate not justpulses but complex pulse trains. A pattern of up to 10 pulses canbe quickly defined with each pulse having its own amplitude, widthand delay. The whole pulse train pattern can then be replayed at auser defined repetition rate. Where variable rise time pulses arerequired, the full arbitrary function can be used.
Arbitrary capability unmatched at thisprice:
The 280 series are highly sophisticated12-bit arbitrary generators capable of recreating virtually anywaveform. True variable clock architecture is used with clockspeeds between 0.1Hz and 40 MHz. This architecture avoids the clockjitter associated with DDS arbitrary generators and permitswaveform linking, looping and sequencing. Waveforms may be definedwith up to 4096 vertical points and from 4 to 65,536 horizontalpoints. Arbitrary waveforms may be replayed at a specified waveformfrequency, period or sample rate. Up to 100 user-defined waveformscan be stored within the instrument’s 256K of nonvolatilememory.
Linked-sequence operation:
Up to sixteen arbitrary waveforms may belinked in a sequence. Each waveform can have a loop count of up to32,768 and the whole sequence can be run continuously or repeatedmore than a million times. For multi-channel models, waveforms ondifferent channels can be ‘daisy chained’ and looped. By summingthe channel outputs, up to 64 segments can be used to create highlycomplex waveforms.
Multi-channel phaselocking:
Any number of channels can be phaselocked with offsets defined to a resolution of 0.1 degree (or 360degrees/waveform points for arbitrary waveforms). For applicationsrequiring more than four channels, multiple generators can be phaselocked. The 280 series also has the facility for phase locking toanother generator.
Multi-channel Summing:
Waveform Summing sums the waveform fromany channel into the next channel. Alternatively any number ofchannels can be summed with an external signal. This permitscomplex modulations to be created such as noisesuperimposition.
Inter-channel triggering andmodulation:
Because any channel can be triggered bythe previous or next channel, waveforms on different channels canbe ‘daisy chained’ and looped. By summing the channel outputs, upto 64 segments can be used (32 segments for 282). A channel can beused to AM modulate or SCM modulate another channel.
Wide frequency sweep range:
All waveforms can be swept over theirfull frequency range at a rate variable between 30 milliseconds and15 minutes. Sweep can be linear or logarithmic, single orcontinuous. Single sweeps can be triggered from the front panel,the trigger input, or the digital interfaces. Multiple channels canbe swept simultaneously.
Amplitude modulation:
Amplitude Modulation and SuppressedCarrier Modulation are available for all waveforms. Any channel canbe used to modulate another channel. Alternatively all channels canbe modulated simultaneously via the modulation input.
Built-in trigger generator:
All waveforms are available as atriggered burst whereby each trigger edge will produce one burst ofthe carrier. Start and stop phase is fully variable. Both Triggeredand Gated modes can be operated from the internal triggergenerator, from an adjacent channel, an external source or a keypress or remote command. The trigger generator signal is availableas a separate output if required.
Tone switching:
The 280 series can provide triggeredswitching between up to 16 frequencies of standard or arbitrarywaveforms. Tone switching modes can be gated, triggered or FSKusing any trigger source. By summing two channels together it ispossible to generate precise DTMF test signals.
Windows based waveformediting:
Each generator is supplied complete withsophisticated Windows based software for the creation, editing andmanagement of waveforms. This powerful software can be used tocreate arbitrary waveforms from scratch using drawing tools,equations or both together. Real-world waveforms imported from DSOsor other sources can be modified and combined with other waveformsusing editing functions. A library of ‘standard’ waveforms isincluded which can be used as ‘elements’ when creating or modifyingwaveforms. A powerful Equation Editor provides an array ofmathematical functions including logarithmic and geometricoperands. Waveform creation and editing can make use of drawingtools in combination with equations, insertion and manipulation.Multiple waveforms can be further combined using mathematicaloperators to create new waveforms.
Import from DSOs and otherinstruments:
The Windows software incorporates directsupport for uploading waveforms from Tektronix digitaloscilloscopes. A driver for LabWindows CVI from NationalInstruments is available which enables imports from other equipmentto be achieved within the LabWindows environment.
Fully programmable:
via RS-232 or GPIB The 280 seriesincorporates both an RS-232 interface and a GPIB (IEEE-488)interface as standard. These can be used for loading arbitrarywaveforms and for remote control of all instrumentfunctions.
Specifications apply at 18-28 ºC after 30 minuteswarm-up, at maximum output into 50 Ω.
| Arbitrary Waveforms |
| Waveforms | | Maximum waveform size is 65,536 points;minimum waveform size is 4 points. Up to 100 user defined waveformsmay be stored in the 256 K point nonvolatile RAM. Waveforms can bedefined by front panel editing controls or by downloading ofwaveform data via RS-232 or GPIB. |
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| Waveform memory | |
| Vertical resolution | |
| Sample clock | |
| Resolution | |
| Accuracy | |
| Sequencing | | Up to 16 waveforms may be linked. Eachwaveform can have a loop count of up to 32,768. A sequence ofwaveforms can be looped up to 1,048,575 times or runcontinuously. |
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| Output filter | | Selectable between 16 MHz Elliptic, 10 MHzElliptic, 10 MHz Bessel or none |
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Standard Waveforms
| All Waveforms |
| Accuracy | |
| Temp. stability | |
| Output level | | 2.5 mV to 10 Vpp into 50 Ω |
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| Sine, Cosine, Haversine,Havercosine |
| Range | |
| Resolution | |
| Harmonic distortion | | < 0.1 % THD to 100 kHz; | | < –65 dBc to 20 kHz, | | < –50 dBc to 300 kHz, | | < –35 dBc to 10 MHz | | < –30 dBc to 16 MHz |
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| Nonharmonic spurii | | < –65 dBc to 1 MHz, | | < –65 dBc + 6 dB/octave 1 MHz to 16MHz |
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| Square |
| Range | |
| Resolution | |
| Accuracy | |
| Rise/fall times | |
| Pulse and Pulse Train |
| Rise/fall times | |
| Period range | |
| Period resolution | |
| Accuracy | |
| Delay range | |
| Delay resolution | | 0.002 % of period or 25 ns, whichever isgreater |
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| Width range | |
| Width resolution | | 0.002 % of period or 25 ns, whichever isgreater |
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| Triangle |
| Range | |
| Resolution | |
| Linearity error | |
| Ramps and Sin(x)/x |
| Range | |
| Resolution | |
| Linearity error | |
Note: The pulse width and absolute value of the delay may not exceed the pulse period at any time. Repetition rate is set by the pulse train period. Operating Modes
| Operating Modes |
| Continuous | | Waveform runs continuously |
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| Triggered Burst | | Each active edge of the trigger signalwill produce one burst of the waveform |
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| Carrier waveforms | | All standard and arbitrary |
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| Max. Carrier Frequency | | 40 Msamples/s for ARB and Sequence. 1 MHzor the maximum for the selected waveform. |
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| Number of cycles | |
| Trigger repetition | | 0.005 Hz to 100 kHz internal dc to 1 MHzexternal |
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| Trigger signal source | | Internal from keyboard, previous channel,next channel or trigger generator. External from TRIG IN or remoteinterface. |
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| Trigger start/stop phase | | ± 360 ° settable with 0.1 ° resolution,subject to waveform frequency and type |
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| Gated | | Waveform will run while the Gate signalis true and stop while false | |
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| Carrier waveforms | | All standard and arbitrary |
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| Max. carrier frequency | | 40 Msamples/s for ARB and Sequence. 1 MHzor the maximum for the selected waveform. |
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| Number of cycles | |
| Trigger repetition | | 0.005 Hz to 100 kHz internal dc to 1 MHzexternal |
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| Gate signal source | | Internal from keyboard, previous channel,next channel or trigger generator. External from TRIG IN or remoteinterface. |
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| Gate start/stop phase | | ± 360 ° settable with 0.1 ° resolution,subject to waveform frequency and type |
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| Sweep | | Frequency sweep capability is providedfor both standard and arbitrary waveforms. Arbitrary waveforms areexpanded or condensed to exactly 4096 points and DDS techniques areused to perform the sweep. | |
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| Carrier waveforms | | All standard and arbitrary except pulse,pulse train and sequence |
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| Sweep mode | | Linear or logarithmic, triggered orcontinuous |
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| Sweep direction | | Up, down, up/down or down/up |
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| Sweep range | | From 1 mHz to 16 MHz in one range. Phasecontinuous. Independent setting of the start and stopfrequency. |
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| Sweep time | |
| Marker | |
| Sweep trigger source | | The sweep may be free run or triggeredfrom the following sources: Manually from keyboard. Externally fromTRIG IN input or remote interface. |
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| Sweep hold | | Sweep can be held and restarted by theHOLD key |
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| Multi channel sweep | | Any number of channels may be sweptsimultaneously but the sweep parameters will be the same for allchannels. Amplitude, Offset and Waveform can be set independentlyfor each channel. |
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| Tone Switching | | Capability provided for both standardand arbitrary waveforms. Arbitrary waveforms are expanded orcondensed to exactly 4096 points and DDS techniques are used toallow instantaneous frequency switching. | |
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| Carrier waveforms | | All except pulse, pulse train andsequence |
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| Frequency list | | Up to 16 frequencies from 1 mHz to 10MHz |
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| Trigger repetition rate | | 0.005 Hz to 100 kHz internal. DC to 1 MHzexternal. Usable repetition rate and waveform frequency depend onthe tone switching mode. |
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| Source | | Internal from keyboard, previous channel,next channel or trigger generator. External from TRIG IN or remoteinterface. |
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| Tone switching modes | |
| Gated | | The tone is output while the triggersignal is true and stopped, at the end of the current waveformcycle, while the trigger signal is false. The next tone is outputwhen the trigger signal is true again. |
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| Triggered | | The tone is output when the trigger signalgoes true and the next tone is output, at the end of the currentwaveform cycle, when the trigger signal goes true again. |
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| FSK | | The tone is output when the trigger signalgoes true and the next tone is output, immediately, when thetrigger signal goes true again. Using 2 channels with their outputssummed together it is possible to generate DTMF testsignals. |
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| Trigger Generator | | Internal source 0.005 Hz to 100 kHzsquare wave adjustable in 10 us steps. 3-digit resolution.Available for external use from any SYNCOUT socket. | |
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Outputs
| Main Outputs – One for eachchannel |
| Output impedance | |
| Amplitude | | 5 mV to 20 Vpp open circuit (2.5 mV to 10Vpp into 50 Ω). Amplitude can be specified open circuit (hi Z) orinto an assumed load of 50 Ω or 600 Ω Vpkpk, Vrms or dBm. |
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| Amplitude accuracy | | 2 % ± 1 mV at 1 kHz into 50 Ω |
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| Amplitude flatness | | ± 0.2 dB to 200 kHz; ± 1 dB to 10 MHz; ±2.5 dB to 16 MHz |
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| DC offset range | | ± 10 V from 50 Ω. Offset plus signal peaklimited to ± 10 V |
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| DC offset accuracy | | Typically 3 % ± 10 mV,unattenuated |
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| Resolution | | 3 digits or 1 mV for both amplitude and dcoffset |
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| Sync Out – One for each channel | | Multifunction output user definable orautomatically selected to be any of the following: | |
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| Waveform sync (all waveforms) | | A square wave with 50 % duty cycle at themain waveform frequency, or a pulse coincident with the first fewpoints of an arbitrary waveform |
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| Position markers | | Any point(s) on the waveform may haveassociated marker bit(s) set high or low |
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| Burst done | | Produces a pulse coincident with the lastcycle of a burst. |
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| Sequence sync | | Produces a pulse coincident with the endof a waveform sequence. |
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| Trigger | | Selects the current trigger signal. Usefulfor synchronizing burst or gated signals. |
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| Sweep sync | | Outputs a pulse at the start of sweep tosynchronize an oscilloscope or recorder. |
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| Phase lock out | | Used to phase lock two generators.Produces a positive edge at the 0 ° phase point. |
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| Output signal level | | TTL/CMOS logic levels from typically 50Ω. |
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| Cursor/marker out | | Adjustable output pulse for use as amarker in sweep mode or as a cursor in arbitrary waveform editingmode. Can be used to modulate the Z axis of an oscilloscope or bedisplayed on a second ‘scope channel. | | Output Signal Level: Adjustable fromnominally 2 V to 14 V, normal or inverted; adjustable width as acursor. |
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| Output impedance | |
Inputs
| Trig In |
| Frequency range | |
| Signal range | | Threshold nominally TTL level; maximuminput ± 10 V |
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| Min. pulse width | | 50 ns, for Trigger/Gate; 50 us for Sweepmode |
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| Polarity | | Selectable as high/rising edge orlow/falling edge |
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| Input impedance | |
| Modulation In |
| Frequency range | |
| VCA signal range | | Approximately 1 V pkpk for 100 % levelchange at maximum output |
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| SCM signal range | | Approximately ± 1 V pk for maximumoutput |
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| Input impedance | |
| Sum In |
| Frequency range | |
| Signal range | | Approximately 2 V pk-pk input for 20 Vpk-pk output |
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| Input impedance | |
| Hold |
| Hold | | Holds an arbitrary waveform at its currentposition. A TTL low level or switch closure causes the waveform tostop at the current position and wait until a TTL high level orswitch opening which allows the waveform to continue. The frontpanel MAN HOLD key or remote command may also be used to controlthe Hold function. While held the front panel MAN TRIG key orremote command may be used to return the waveform to the start. TheHold input may be enabled independently for each channel. |
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| Input impedance | |
| Ref Clock In/Out |
| Set to input | | Input for an external 10 MHz referenceclock. TTL/CMOS threshold level. |
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| Set to output | | Buffered version of the internal 10 MHzclock. Output levels nominally 1 V and 4 V from 50 Ω |
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| Set to phase lock | | Used together with SYNC OUT on a masterand TRIG IN on a slave to synchronise (phase lock) two separategenerators. |
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Inter-Channel Operation
| Inter-Channel Operation |
| Inter-Channel Modulation | | The waveform from any channel may beused to Amplitude Modulate (AM) or Suppressed Carrier Modulate(SCM) the next channel. Alternatively any number of channels may beModulated (AM or SCM) with the signal at the MODULATION inputsocket. | |
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| Carrier frequency | | Entire range for selected waveform |
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| Carrier waveforms | | All standard and arbitrarywaveforms |
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| Modulation types: AM | | Double sideband with carrier. SCM: Doublesideband suppressed carrier |
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| Modulation source | | Internal from the previous channel.External from Modulation input socket. The external modulationsignal may be applied to any number of channelssimultaneously. |
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| Frequency range | |
| Internal AM depth | |
| Internal AM resolution | |
| Carrier suppression (SCM) | |
| External modulation signalrange | | VCA: Approximately 1 V pk-pk for 100 %level change at maximum output |
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| SCM | | Approximately ± 1 V pk for max.output |
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| Inter-Channel Analogue Summing | | Waveform Summing sums the waveform fromany channel into the next channel. Alternatively any number ofchannels may be summed with the signal at the SUM input socket. | |
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| Carrier frequency | | Entire range for selected waveform |
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| Carrier waveforms | | All standard and arbitrarywaveforms |
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| Sum source | | Internal from the previous channel.External from SUM IN socket. |
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| Frequency range | |
| Ext. signal range | | Approx. 5 V pk-pk input for 20 V pk-pkoutput |
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| Inter-Channel Phase Locking | | Two or more channels may be phase lockedtogether. Each locked channel may be assigned a phase anglerelative to the other locked channels. Arbitrary waveforms andwaveform sequences may be phase locked but certain constraintsapply to waveform lengths and clock frequency ratios. | | | With one channel assigned as the Masterand other channels as Slaves a frequency change on the master willbe repeated on each slave thus allowing multiphase waveforms at thesame frequency to be easily generated. DDS waveforms are those with7 digits of frequency setting resolution, while Non-DDS waveformshave 4 digits. | |
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| Phase resolution Non-DDSwaveforms | | DDS waveforms: 0.1 degree or 360degrees/number of points whichever is the greater |
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| Phase error | | < ± 10 ns all waveforms | | The signals from the REF IN/OUT socket andthe SYNC OUT socket can be used to phase lock two instruments wheremore than 4 channels are required. |
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| Inter-Channel Triggering | | Any channel can be triggered by theprevious or next channel. The previous/next connections can be usedto ‘daisy chain’ a trigger signal from a ‘start’ channel, through anumber of channels in the ‘chain’ to an ‘end’ channel. Each channelreceives the trigger out signal from the previous (or next)channel, and drives its selected trigger out to the next (orprevious) channel. | | | The ‘end’ channel trigger out can be setup to drive the ‘start’ channel, closing the loop. In this way,complex and versatile interchannel trigger schemes may be set up.Each channel can have its trigger out and its output waveform setup independently. Trigger out may be selected from Waveform End,Position Markers, Sequence Sync or Burst Done. | | | Using the scheme above it is possible tocreate a sequence of up to 64 waveform segments, each channelproducing up to 16 segments and all channels being summed toproduce the complete waveform at the output of channel 4. | |
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| Interfaces |
| RS-232 | | Variable Baud rate, 9600 Baudmaximum |
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| IEEE-488 | | Conforms with IEEE488.1 andIEEE488.2 |
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| Software included | | Windows™-based software for waveformcreation, editing and management is supplied. Instrument driversLabView and LabWindows CVI drivers are either supplied with theinstrument or are available via your local Flukeoffice |
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| General Specifications |
| Display | | 20 character x 4 row alphanumericLCD |
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| Data entry | | Keyboard selection of mode, waveform etc.;value entry direct by numeric keys or by rotary control |
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| Stored settings | | Up to 9 complete instrument setups may bestored and recalled from battery-backed memory. | | Up to 100 arbitrary waveforms can also bestored independent of the instrument settings. |
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| Size | | 130 mm (3 U) height; 335 mm long; width350 mm (282/284), 212 mm (281) |
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| Weight | | 7.2 kg. (16 lb) (282/284); 4.1 kg (9 lb)(281) |
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| Power | | 230 V, 115 V or 100 V nominal 50/60 Hz,adjustable internally; operating range ± 14 % of nominal;100 VAmax. for 4 channels, 75 VA max. for 2 channel, 40 VA max. for 1channel. Installation Category II. |
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| Operating range | | +5 °C to 40 °C, 20-80 % RH |
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| Storage range | |
| Environmental | | Indoor use at altitudes to 2000 m,Pollution Degree 2 |
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| Options | |
| Safety | |
| EMC | |