Thurlby Thandar Instruments TG4001 User Manual

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TG4001

40MHz DDS Function/Arbi trary Generator

INSTRUCTION MANUAL

Table of Contents

Introduction 3 Specification 4 Safety 9 EMC 11 Installation 12 Connections 14

Front Panel Connections 14 Rear Panel Connections 15

General 17

Initial Operation 17 Principles of Editing 18 Principles of Operation 19

Function Generator Operation 21

Setting Generator Paramet er s 21 Warnings and Error Messages 23 SYNC Output 24

Sweep Operation 26

General 26 Setting Sweep Parameters 26

Triggered Burst and Gate 30

General 30 Triggered Burst 31 Gated Mode 32

Sync Out in Triggered Burst and Gated Mode 33 Tone Mode 34 Arbitrary Waveform Generat ion 36

Introduction 36

Selecting and Outputting Arbitrary Waveforms 36

Frequency and Amplitude Control with Arbitrary W aveforms 37

Sync Out Settings with Arbitrary Waveforms 37

Output Filter Setting 37 Pulse and Pulse-trains 39

Pulse Set-up 39

Pulse-train Setup 40 Modulation 43

Sum 44 Synchronising Two Generators 45 System Operations from the Ut ility Menu 47 Calibration 49

Equipment Required 49 Calibration Procedure 49 Calibration Routine 50 Remote Calibration 51

Remote Operation 52

Power on Settings 59

Remote Commands 60

Frequency and Period 61 Amplitude and DC Offset 61 Waveform Selection 61 Arbitrary Waveform Define 62 Arbitrary Waveform Inter rogation 62 Mode Commands 62 Input/Output control 63 Modulation Commands 63 Synchronising Commands 63 Status Commands 63

Miscellaneous Commands 64 Remote Command Summary 65 Maintenance 68 Appendix 1. Warning and Error Messages 69 Appendix 2. SYNC OUT Aut om atic Settings 71 Appendix 3. Factory System Defaults 72 Appendix 4. Waveform Manager Plus Arbitrary Waveform Creation and Management Software 73

Introduction

This synthesised programmable func t ion generator has the following features:

• Sinewaves up to 40MHz, squarewaves up to 50MHz

• 11 standard waveforms available plus pulse and arbitrary

• User defined pulses and pulse trains with 10ns resolution

• Arbitrary waveforms up to 100MHz sampling frequency

• Up to 4 arbitrary waveforms of 4 to 64k points with 12 bit vertical resolution

• Triggering, summing and modulation of all output waveforms

• RS232 and USB and optional GPIB interfaces

The instrument uses a combination of direct digital synthesis and variable clock techniques to provide high performance and extensive facilities in a compact instrum ent. It can generate a wide variety of waveforms between 0·1mHz and 50MHz with high resolution and accuracy.

Arbitrary waveforms may be played back with 12 bit vertical resolution and from 4 to 65536 horizontal points.

All waveforms can be swept over their full frequency range at a rate variable between 1 millisecond 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. A sweep marker is provided.

Amplitude Modulation is available for all waveforms and is controlled from an external generator via the MODULATIO N input socket.

Signal Summing is available for all waveforms and is controlled from an exter nal generator via the SUM input socket.

All waveforms are available as a Triggered Burst whereby each active edge of the trigg er signal will produce one burst of the carrier. The number of cycles in the burst can be set between 1 and

1048575. The Gated mode turns the output sig nal O n when the g at ing signal is true and Off when it is false. Both Triggered and Gated modes can be operated fr om the internal Trigger Generator (0.005Hz to 100kHz), f rom an external source (dc to 1MHz) or by a key press or remote command.

The signals from the REF IN/ O UT sock et and the SYNC OUT socket can be used to phase lock two instruments. This can be used to generate multi−phase waveforms or locked waveforms of different frequencies.

The generator parameters ar e clear ly displayed on a backlit LCD with 4 rows of 20 charact er s. Soft−keys and sub menus are used to guide the user through even the most complex funct ions.

All parameters can be entered directly from the num eric keypad. Alternatively most parameters can be incremented or decremented using t he r otar y contr ol. This system combines quick and easy numeric data entry with quasi−analogue adjustment when required.

The generator has RS232 and USB interfaces as s tandard which can be used f or r emote control of all of the instrument functions or for the down−loading of ar bit r ary waveforms. As well as operating in conventional RS232 mode the serial interf ace can also be us ed in addres sable mode whereby up to 32 instruments can be linked to a single PC serial port.

There is also a GPIB option.

Range:

0·1mHz to 40MHz

Resolution:

0·1mHz or 10 digits

Accuracy:

10 ppm for 1 year

Temperatur e Stability:

Typically <1 ppm/ºC.

Output Level:

2.5mV to 10Vp−p into 50Ω

Harmonic Distortion:

<0.15% THD to 100kHz; <–60dBc to 20kHz

<–50dBc to 1MHz,

<−40dBc to 10MHz

<−30dBc to 40MHz

Non−harmonic Spurii:

<–60dBc to 1MHz, <–60dBc + 6dB/octave 1MHz to 40MHz

Range:

1mHz to 50MHz

Resolution:

1mHz (8 digits)

Accuracy:

10 ppm for 1 year

Output Level:

2.5mV to 10Vp−p into 50Ω

Rise and Fall Times:

<8ns

Range:

0.1mHz to 500kHz

Resolution:

0.1mHz or 10 digits

Accuracy:

10 ppm for 1 year

Output Level:

2.5mV to 10Vp−p into 50Ω

Linearity Error:

<0.1% to 30 kHz

Range:

0.1mHz to 500kHz

Resolution:

0.1mHz (10 digits)

Accuracy:

10 ppm for 1 year

Output Level:

2.5mV to 10Vp−p into 50Ω

Linearity Error:

<0.1% to 30 kHz

Specifications apply at 18−28ºC after 30 minutes warm−up, at maximum output into 50Ω.

WAVEFORMS Standard Waveforms

Sine, square, triangle, DC, positive ramp, negative ramp, sin(x)/x, pulse, pulse train, cosine, haversine, havercosine and 4 user defined Arbitrary waveforms.

Sine, Cosine, Haversine, Havercosine

Specification

Square

Triangle

Ramps and Sin(x)/x

Output Level:

2.5mV to 10Vp−p into 50Ω

Rise and Fall Times:

<8ns

Period:

Range:

40ns to 100s

Resolution:

8 digit

Accuracy:

10 ppm for 1 year

Resolution:

0·001% of period or 10ns, whichever is greater

Resolution:

0·001% of period or 10ns, whichever is greater

minimum waveform size is 4 points

Vertical Resolution:

12 bits

Sample Clock Range:

100mHz to 100MHz

Resolution:

8 digits

Accuracy:

10 ppm for 1 year

Carrier Waveforms:

All standard and arbitrary

waveform. 100Msamples/s for ARB.

Number of Cycles:

1 to 1,048,575

dc to 1MHz external.

External from TRIG IN or remote interface.

frequency and type.

Pulse and Pulse Train

Delay: Range:

Width: Range:

Note that the pulse width and absolute value of the delay may not exceed the pulse period at any time.

Pulse trains of up to 10 pulses may be specified, each pulse having independently defined width, delay and level. The baseline voltage is separately defined and the sequence repetition rate is set by the pulse train period.

Arbitrary

Up to 4 user defined waveforms may be stored in non-volatile memory. Waveforms can be defined by downloading of waveform data via RS232, GPIB or USB.

Waveform Memory Size:

−99·99s to + 99·99s

10ns to 99·99s

4 waveforms – maximum waveform size is 65536 points,

Output Filter

Selectable between 40MHz Elliptic, 20MHz Bessel or none.

Noise

Digital noise generated by a 35-bit linear feedback register clocked at 100MHz. User’s external filter defines bandwidth and response.

OPERATING MODES Triggered Burst

Each active edge of the trigg er s ig nal will produce one burst of the waveform.

Maximum Carrier Frequency: The smaller of 2.5MHz or the maximum for the selected

Trigger Repetition Rate: 0.005Hz to 100kHz internal

Trigger Signal Source: Internal from keyboard or t r igger generator.

Trigger Start/Stop Phase:

± 360° settable with 0.1° resolution, subject t o waveform

Carrier Waveforms:

All standard and arbitrary.

waveform. 100Msamples/s for ARB.

Trigger Repetition Rate:

0.005Hz to 100kHz internal; dc to 1MHz external.

External from TRIG IN or remote interface.

frequency and type.

Carrier Waveforms:

All standard and arbitrary except pulse and pulse train.

Sweep Mode:

Linear or logarithmic, trig gered or continuous.

Sweep Direction:

Up, down, up/down or down/up.

Independent setting of t he star t and stop frequency.

Sweep Time:

1ms to 999s (3 digit resolution).

Marker:

Variable during sweep.

interface.

Carrier Waveforms:

All waveforms except pulse and pulse train.

Frequency List:

Up to 16 frequencies fr om 1m Hz t o 40MHz.

switching mode.

External from TRIG IN or remote interface.

again.

when the trigger signal goes tr ue again.

again.

Gated

Waveform will run while the Gate signal is true and stop while false.

Maximum Carrier Frequency: The smaller of 2.5MHz or the maximum for the selected

Gate Signal Source: Internal from keyboard or t r igger generator.

Gate Start/Stop Phase:

Sweep

Frequency sweep capability is provided for both standard and arbitrary waveforms. Arbitrary waveforms are expanded or condensed to exactly 4096 points and DDS techniques are used to perform the sweep.

Sweep Range: From 1mHz to 40MHz in one range. Phase continuous.

Sweep Trigger Source: The sweep may be free run or trigg er ed from the following sources:

Tone Switching

Capability provided for both standard and arbitrary waveforms. Arbitrary waveforms are expanded or condensed to exactly 4096 points and DDS techniques are used to allow instantaneous frequency switching.

± 360° settable with 0.1° resolution, subject t o waveform

Manually from keyboard. Externally from TRIG IN input or remot e

Trigger Repetition Rate: 0.005Hz to 100kHz internal; dc to 1MHz external.

Usable repetition rate and waveform freq uency depend on the t one

Source: Internal from keyboard or t r igger generator.

Tone Switching Modes:

FSK: The tone is output when the trigger signal goes true and the

Using 2 instruments with their outputs summed together it is possible to generate DTMF test signals.

Gated: The tone is output while the trigger signal is true and stopped, at the end of the cur r ent waveform c ycle, while the trig ger signal is false. The next tone is output when the trigger signal is true

Triggered: The tone is output when the trig ger signal goes true and the next tone is output, at the end of t he c ur r ent waveform cycle,

next tone is output, immediately, when the trigger signal goes true

Output Impedance:

50Ω

600Ω in Vpk−pk, Vrms or dBm.

Amplitude Accuracy:

2% ±1mV at 1kHz into 50Ω.

Amplitude Flatness:

± 0.2dB to 1MHz; ± 0.4dB to 40MHz

DC Offset Range:

±10V. DC off s et plus signal peak limited to ±10V from 50Ω.

DC Offset Accuracy:

Typically 3% ±10mV, unattenuated.

Resolution:

3 digits or 1mV for both Amplitude and DC Offset.

(all waveforms)

a pulse coincident with the first few points of an arbitr ar y waveform.

Burst Done:

Produces a pulse coincident with the last cycle of a burst.

gated signals.

oscilloscope or recorder. Can additionally output a sweep marker.

phase point.

point.

Frequency Range:

DC − 1MHz.

Signal Range:

Threshold level adjustable ±5V; maximum input ±10V.

Minimum Pulse Width:

50ns, for Trigger and Gate modes; 50us for Sweep mode.

Polarity:

Selectable as high/rising edge or low/falling edge.

Input Impedance:

10kΩ

Frequency Range:

DC – 100kHz.

SCM: Approximately ± 1Vpk for maximum output.

Input Impedance:

Typically 1 kΩ.

Trigger Generator

Internal source 0.005 Hz to 100kHz square wave adjustable in 10us steps. 3 digit resolution. Available for external use from the SYNC OUT socket.

OUTPUTS Main Output

Amplitude:

Sync Out

Multifunction output user definable or automatically selected to be any of the following: Waveform Sync:

Trigger: Selects the current trigger signal. Useful for synchronizing burst or

Sweep Sync: Outputs a trigger signal at t he s tart of sweep to synchronize an

Phase Lock Out: Used to phase lock two generators. Produces a pos it ive edge at t he 0°

Output Signal Level: Logic levels of <0.8V & >3V, except for Sweep Sync. Sweep Sync is a

5mV to 20Vp−p open circuit (2.5mV to 10Vp−p into 50Ω). Amplitude can be specified open circuit (hi Z) or into an assumed load of 50Ω or

A square wave with 50% duty cycle at the main waveform frequency, or

3-level waveform: low at start of sweep, high for the dur at ion of the last frequency step at end of s weep, with a narrow 1V pulse at the mar ker

INPUTS Trig In

Modulation In

Signal Range:

VCA: Approximately 1V pk−pk for 100% level change at m aximum output; maximum input ± 10V.

Frequency Range:

DC − 30 MHz .

±10V.

Input Impedance:

Typically 1kΩ.

level.

1V and 4V from 50Ω.

to synchronise (phase lock) two separate generators .

Maximum Input Voltage:

+5V, –1V.

RS232:

Variable Baud rate, 38400 Baud maximum. 9−pin D−connector.

IEEE−488:

Optional - Conforms with IEEE488.1 and IEEE488.2

USB

1.1

Display:

20 character x 4 row alphanumeric LCD.

numeric keys or by rotary control.

non-volatile memory.

Size:

3U (130mm) height; 212mm ( ½ −rack) width; 335mm long.

Weight:

4.1kg (9lb).

nominal; 60VA max. Installation Category II.

Operating Range:

+5°C to 40°C, 20−80% RH.

Storage Range:

−20°C to + 60°C.

Environmental:

Indoor use at altitudes up to 2000m, Pollution Degr ee 2.

Options:

19 inch rack mounting kit, GPIB remote control interface.

Safety:

Complies with EN61010−1.

EMC:

Complies with EN61326

Sum In

Signal Range:

Ref Clock In/Out

Set to Input: Input for an external 10MHz reference clock. TTL/ CMOS threshold

Set to Output: Buffered version of the internal 10MHz clock. Output levels nominally

Set to Phase Lock: Used together with SYNC OUT on a master and TRIG IN on a slave

INTERFACES

Full remote control facilities are available through the RS232, USB or G PI B interfaces.

GENERAL

Approximately 2 Vpk−pk input for 20Vpk −pk output; maximum input

Data Entry: Keyboard selection of mode, waveform etc.; value entry direct by

Stored Settings:

Power: 220-240V nominal 50/60Hz; 110-120V or 100V nominal 50/60/400Hz;

Up to 9 complete instrument set−ups may be stored and r ec alled from

nominal voltage adjustable internally; operating range ±10% of

incorrect operation may damage the instr um ent.

Safety

This generator is a Safet y Class I instr um ent according to IEC classification and has been designed to meet the requirem ents of EN61010−1 (Safety Requirements for Elect r ical Eq uipm ent for Measurement, Control and Laborator y Use). It is an Installation Category II instrument intended for operation from a normal single phase supply.

This instrument has been tested in accordanc e with EN61010−1 and has been supplied in a safe condition. This instruction manual contains some information and warnings which have to be followed by the user to ensure safe operation and to r etain the inst rument in a safe condition.

This instrument has been designed f or indoor use in a Pollution Degree 2 environment in the temperature range 5°C to 40°C, 20% − 80% RH (non−condensing). It may occasionally be subjected to temperatures between +5° and −10°C without degradation of its safety. Do not operate while condensation is present.

Use of this instrument in a manner not spec ified by these instructions may impair the safety protection provided. Do not operate the instrum ent outside its rat ed supply voltages or environmental range.

WARNING! THIS INSTRUMENT MUST BE EARTHED

Any interruption of the mains earth conduct or inside or outside t he inst r um ent will make the instrument dangerous. Int entional interruption is prohibited. The protective action must not be negated by the use of an extension cord without a protective conductor.

When the instrument is connected to its supply, terminals may be live and opening the covers or removal of parts (except those to which access can be gained by hand) is likely to expose live parts. The apparatus shall be disconnected from all voltage sources before it is opened for any adjustment, replacement, m aint enance or repair.

Any adjustment, maintenance and repair of the opened instrument under voltage shall be avoided as far as possible and, if inevitable, shall be carried out only by a skilled person who is aware of the hazard involved.

If the instrument is clearly def ec t ive, has been subject to mechanical damage, excessive moisture or chemical corrosion the safety protection may be impaired and the apparatus should be withdrawn from use and returned for checking and repair.

Make sure that only fuses with the required rated current and of the specified type are used f or replacement. The use of makeshift fuses and the short−circuiting of fuse holders is prohibited.

This instrument uses a Lithium button c ell for non−volatile memory battery back−up; t ypic al life is 5 years. In the event of replacement becom ing nec essary, replace only with a cell of the cor r ect type, i.e. 3V Li/Mn0 in accordance with local regulations; do not cut open, incinerate, expose to t em per atures above 60°C or attempt to recharge.

Do not wet the instrument when cleaning it and in particular use only a soft dry cloth to clean the LCD window. The following symbols are used on t he inst r um ent and in this manual:−

20mm button cell type 2032. Exhausted cells must be disposed of car efully

Caution −refer to t he acc om panying documentation,

terminal connected to chassis ground.

mains supply OFF. mains supply ON.

alternating current.

Performance levels achieved are detailed in the user manual.

EC Declaration of Conf ormity

We Thurlby Thandar Instruments Ltd Glebe Road Huntingdon Cambridgeshire PE29 7DR England

declare that the

TG4001 40MHz DDS Function/Arbitrary Generator

meets the intent of the EMC Directive 2004/108/EC and the Low Voltage Directive 2006/95/EC. Compliance was demonstrated by conformance to the following specifications which have been listed in the Official Journal of the European Comm unit ies.

EMC

Emissions: a) EN61326-1 (2006) Radiated, Class A

b) EN61326-1 (2006) Conducted, Class B c) EN61326-1 (2006) Har m onics, referring to EN61000-3-2 (2006)

Immunity: EN61326-1 (2006) Immunity Table 1, referring to:

a) EN61000-4-2 (2009) Electrostatic Discharge b) EN61000-4-3 (2006) Electromagnetic Field c) EN61000-4-11 (2004) Voltage Interrupt d) EN61000-4-4 (2004) Fast Transient e) EN61000-4-5 (2006) Surge f) EN61000-4-6 (2009) Conduct ed RF

Safety EN61010-1 Installation Category II, Pollution Degree 2.

CHRIS W ILDING TECHNICAL DIRECTOR

2 January 2013

This instrument has been designed to meet the requirements of the EMC Directive 2004/108/EC. Compliance was demonstrated by meeting the test limits of t he following standards:

Emissions

EN61326-1 (2006) EMC product standard for Electrical Equipment for Measurement, Control and Laboratory Use. Test limits used were:

a) Radiated: Class A b) Conducted: Class B c) Harm onics: EN61000-3-2 (2006) Class A; the instrument is Class A by product category.

Immunity

EN61326-1 (2006) EMC product standard for Electrical Equipment for Measurement, Control and Laboratory Use.

Test met hods, limits and performance achieved are shown below (requirement shown in brackets):

a) EN61000-4-2 (2009) Electrostatic Discharge : 4kV air, 4kV contact, Performance A. b) EN61000-4-3 (2006) Electromagnetic Field:

EMC

3V/m, 80% AM at 1kHz, 80MHz – 1GHz: Performance A (A) and 1.4GHz to 2GHz: Performance A (A); 1V/m, 2.0GHz to 2.7GHz: Perf or m anc e A (A).

c) EN61000-4-11 (2004) Voltage Interrupt: ½ cycle and 1 cycle, 0%: Performance A (B);

d) EN61000-4-4 (2004) Fast Transient, 1kV peak (AC line), 0·5kV peak ( signal lines and RS232/GPIB ports), Perform ance A.

e) EN61000-4-5 (2006) Surge, 0·5kV (line t o line), 1kV (line to ground), Perform ance A. f) EN61000-4-6 (2009) Conducted RF, 3V, 80% AM at 1kHz (AC line only; signal

connections <3m, therefor e not tested), Performance A. According to EN61326-1 the definitions of performance criteria are:

Performance criterion A: ‘During test normal performance within the specificat ion limits.’ Performance criterion B: ‘During t est , temporary degradation, or loss of function or

performance which is self-recovering’. Performance criterion C: ‘During t est, temporary degradation, or loss of function or

performance which requires operator int er vention or s ystem r es et occ ur s.’

Cautions

To ensure continued com pliance with the EMC directive observe the following precautions: a) Connect generator to other equipment using only high quality, double-screened cables. b) After opening the case for any reason ens ur e t hat all signal and ground connections are

25 cycles, 70% and 250 cycles, 0%: Performance B (C).

remade correctly and that case screws are correc t ly refitted and tightened.

c) In the event of part replacement becoming necessary, only use components of an identical

type, see the Service Manual.

for 230V operation:

500 mA (T) 250V HRC

for 100V or 115V operation:

1A (T) 250V HRC

Mains Operating Voltage

Check that the instrument oper ating voltage marked on the rear panel is suitable for the local supply. Should it be neces sar y to change the operating voltage, proceed as follows:

1) Disconnect the inst r um ent from all voltage sources.

2) Remove the screws which retain the top cover and lift off the cover.

3) Change the t ransformer connections following the diagr am below.

4) Refit t he cover and t he s ecur e with the sam e s cr ews.

5) To comply with safety standard requirements the operating voltage marked on the rear panel must be changed to clearly show the new voltage setting.

6) Change the fuse to one of the correct r at ing, see below.

Installation

Fuse

for 230V operation connect the live (brown) wire to pin 15 for 115V operation connect the live (brown) wire to pin 14 for 100V operation connect the live (brown) wire to pin 13

7) Refit t he cover and t he s ecur e with the sam e s cr ews.

8) To comply with safety standard requirements the operating voltage marked on the rear panel must be changed to clearly show the new voltage setting.

9) Change the fuse to one of the correct r at ing, see below.

Ensure that the correct mains fuse is fitted for the set oper ating voltage. The correct mains fuse types are:

To replace the fuse, disconnect the mains lead from the inlet soc ket and withdraw the fuse drawer below the socket pins. Change the fuse and replace t he dr awer.

The use of makeshift fuses or the short−circuiting of the fuse holder is prohibited.

Brown

−

Mains Live

Blue

−

Mains Neutral

Green / Yellow

−

Mains Earth

Mains Lead

When a three c or e m ains lead with bare ends is provided it should be connected as follows:−

Mounting

This instrument is suitable both for bench use and rack mounting. It is delivered with feet for bench mounting. The front feet include a tilt mechanism for optimal panel angle.

A rack kit for mounting in a 19” rack is available from the Manufacturers or their overseas agents.

Ventilation

The generator uses a small f an fitted to the rear panel. Tak e car e not to restrict the rear air inlet or the vents at the front (sides and underneath). In rack-mounted situat ions allow adequate space around the instrument and/or use a f an t r ay for forced cooling.

WARNING! THIS INSTRUMENT MUST BE EARTHED

first few points (addresses) of the waveform.

waveform is active at the main output and high at all other tim es.

external, manual and remote all produce a trigger sync.

marker pulse can be set to be output at any of the frequency steps.

coherent.

Front Panel Connec tions

MAIN OUT

This is the 50Ω output from the main generator. It will provide up to 20V peak−to−peak e.m.f. which will yield 10V peak−to−peak into a matched 50Ω load. It can tolerate a short circuit for 60 seconds.

Do not apply an external voltage to this output.

SYNC OUT

This is a TTL/CMOS level output which may be set to any of t he following signals from the

SYNC OUT screen.

Connections

waveform sync

Burst done

Trigger

Sweep sync

Phase lock

SYNC OUT logic levels are nominally 0V and 5V from typically 50Ω. SYNC OUT will withstand a short circuit.

Do not apply an external voltage to this output.

A sync marker phase coincident with the MAIN OUT waveform. For standard waveforms, (sine, cosine, haversines, squar e, triangle, sinx/x and ramp), the sync marker is a squarewave with a 1:1 duty cycle with the rising edge at the 0º phase point and the f alling edge at the 180º phase point. For arbitrary waveforms the sync marker is a positive pulse coincident with the

Provides a signal during Gate or Trigger modes which is low while the

Provides a positive going version of the actual trigg er signal; internal,

Goes low at the start of sweep and high for t he dur at ion of the last frequency step at the end of the sweep. In addition, a half-amplitude

Produces a positive edge coincident with the start of the curr ent waveform; this is used for phase locking instr um ents. This waveform may not appear

TRIG IN

This is the external input for Trigger, Gate, Sweep and Sequence operations. It is also the input used to synchronise the generator (as a slave) to anot her (which is the master).

Do not apply an external voltage exceeding ±10V.

internal clock when the external reference is applied.

output

The internal 10MHz clock is made available at the socket.

phase lock slave and the master is set to phase lock master.

Name

Description

TXD

Transmitted data from instrument

RXD

Received data to instrument

No internal connection

GND

Signal ground

6 − No internal connection

RXD2

Secondary received data

TXD2

Secondary transmitted data

GND

Signal ground

Rear Panel Connections

MODULATION IN

This is the input socket f or exter nal modulat ion.

Do not apply an external voltage exceeding ±10V.

SUM IN

This is the input socket f or exter nal sig nal sum m ing.

Do not apply an external voltage exceeding ±10V.

REF CLOCK IN/OUT

The function of the CLO CK IN/ O UT sock et is set from the ref clock i/o menu on the

UTILITY screen, see System Operations section. input

phase lock

As an output the logic levels are nominally 1V and 4V from typically 50Ω. CLO CK OUT will withstand a short−circuit. As an input the threshold is TTL/CMOS compatible.

Do not apply an external voltage exceeding + 5V or –1V.

MAIN OUT

This plugged panel position is provided for the user to fit a 50Ω BNC as an alternative to the front panel MAIN OUT socket where rear panel connections are required in a rack-mounted system. The front panel MAIN OUT connection must be carefully disconnected fr om the pcb and the pcb then rewired, using high quality 50Ω coax, to the new rear panel connector.

RS232

9−pin D−connector compatible with addressable RS232 use. The pin connections are shown below:

This is the default setting . The sock et bec om es an input for an external 10MHz reference clock. The system automatically switches over from the

When two or more generators are synchronised the slaves are set to

Do not apply external voltages exceeding + 5V or –1V to this signal connection.

Do not apply an external voltage to this output.

−

Pin 2, 3 and 5 may be used as a conventional RS232 interface with XON/XOFF handshak ing . Pins 7, 8 and 9 are additionally used when the instrument is used in addressable RS232 mode. Signal grounds are connected to instrum ent ground. The RS232 address is set from the

No internal Connection

remote menu on the UTILITY screen, see System Operations sec t ion.

GPIB (IEEE−488) OPTIONAL

The GPIB interface is not isolated; the GPIB signal grounds are connected to t he inst rument ground.

The implemented subsets are:

SH1 AH1 T6 TE0 L4 LE0 SR1 RL1 PP1 DC1 DT1 C0 E2

USB

The GPIB address is set fr om t he Operations section.

The USB port is connected to instrument ground. It accepts a standard USB cable. If USB has been selected as the current interf ac e t he Windows plug-and-play function should autom at ically recognise that the instrument has been c onnected.

remote menu on the UTILITY screen, see System

Initial Operation

This section is a general introduction to t he or ganisation of the instrument and is intended to be read before using the gener at or for the first time. Detailed operation is covered in later sections starting with Standard Waveform Operation.

In this manual front panel keys and sockets are s hown in capitals, e.g. OFFSET, SYNC OUT; all soft−key labels, entry fields and messages displayed on the LCD are shown in a different type−font, e.g.

Switching On

The power switch is located at the bottom left of the front panel. At power up the generator displays the installed software revision whilst loading its waveform

RAM; if an error is encountered the message

firmware updated will be displayed, see the Warning s and Er r or Messages sec t ion.

Loading takes a few seconds, after which the status scr een is displayed, showing the g enerator parameters set to their def ault values, with the MAIN OUT output set off. Refer to the System Operations section for how to change t he power up settings to either those at power down or to any one of the stored settings. Recall the stat us s cr een at any time with the STATUS key; a second press returns the display to the previous screen.

General

WAVEFORM FUNCTIONS, sine.

system ram error, battery fault or

Change the basic generator parameters as des cr ibed in the Standard Waveform Oper at ion section and switch the output on with the MAIN OUT key; the ON lamp will light to show that the output is on.

Display Contrast

All parameter settings are displayed on the 20 character x 4 row backlit liquid cr ystal display (LCD). The contrast may vary a little with changes of ambient tem per at ur e or viewing angle but can be optimised for a particular environment by using the front panel contrast control. Insert a small screwdriver or trimmer tool through the adjustment aperture mark ed LCD and rotat e t he control for optimum contrast.

Keyboard

Pressing the front panel keys displays screens which list parameters or choices r elat ive to the key pressed. Selections are then made using the display soft−keys and numeric values are changed using the numeric keys or rotar y contr ol, see t he Pr inciples of Editing section.

The keys are grouped as follows:

• FUNCTION, FREQuency , AMPLitude, OFFSET and MODE keys display screens which permit their respective parameters to be edited either from the numeric keypad or using the rotary control/cursor keys.

• Numeric keys permit direct entry of a value for the parameter currently selected. Values are accepted in four formats: int eger (20), floating point (20· 0), exponential (2 EXP 1) and direct units selection (20Hz). For example, to set a new frequency of 50kHz press FREQ followed by 50000 ENTER or 5 EXP 4 ENTER or 50 kHz. ENTER or an appropriate units key confirms the numeric entry and changes the gener at or s et t ing to the new value. CE (Clear Entry) undoes a numeric entry digit by digit. ESCAPE returns a set ting being edited to its last value.

• MODULATION, SUM, TRIG IN and SYNC O UT call s c reens from which the parameters of those input/outputs can be set, including whether the port is on or off.

• SWEEP similarly calls screens from which all the parameters can be set and the function run.

• The MAIN OUT key simply switches the main output on or off.

• MAN TRIG is used for manual triggering (when TRIG IN is appropriately set) and for

synchronising two or more generators when suitably connected together.

♦ ◊ ◊

◊

• UTILITY gives access to menus for a variety of functions such as remote control interface

set−up, power−up parameters, error message settings and store/rec all waveforms t o/from non−volatile memory.

• Eight soft−keys around the display are used to directly set or s elect paramet ers from the currently displayed menu; their operation is described in more detail in the next section.

• The STATUS key always returns the display to the default start−up screen which gives an overview of the generators status. Pressing STAT US ag ain returns the display to the previous screen.

Further explanations will be found in the detailed descriptions of the generat or’s operation.

Principles of Editing

Each screen called up by pressing a front panel key shows parameter value(s) and/or a list of choices. Parameter values can be edited by using the ROTARY CONTROL in combination with the left and right arrowed CURSOR keys, or by direct num er ic keyboard entry; choices are made using the soft−key associated with the screen it em to be selected. The examples which follow assume factory default set t ings.

A diamond beside a screen item indicates that it is selectable; hollow diamonds identify deselected items and filled diamonds denote selected items. For example, press MODE to get the screen shown below:

MODE:

continuous gated setup…◊ triggered setup…◊

The filled diamond indicates that the selected m ode is continuous. Gated or

Triggered modes are selected by pressing the associated soft−key which will make the

diamond beside that item filled and the diamond beside also illustrates how an ellipsis (three dots following the screen text) indicates that a further screen

follows when that item is selected. In the case of t he MODE screen illustr at ed, pressing the

continuous hollow. This screen

setup... soft−key on the bottom line brings up t he TRIGGER SETUP menu; note that

selecting this item does not change t he Some screen items are marked with a double−headed arr ow (a split diamond) when selected to

indicate that the item’s setting can be changed by fur ther presses of the soft−key, by pressing either cursor key or by using the rotary control. For example, pr es sing FILTER brings up the screen shown below.

FILTER SETUP

mode: auto

type: 40MHz eliptic

continuous/gated/triggered selection.

Repeated presses of the mode soft−k ey will toggle the m ode between its two possible settings

auto and manual. Similarly, when type is selected, repeated presses of the type

of soft−key (or cursor keys or use of the rotary control) will step the selection through all possible

settings of the filter type. In addition to their use in editing items identified by a double−headed arrow as described above,

the CURSOR keys and ROTARY CONTROL operate in two other modes. In screens with lists of items that can be selected ( i. e. it em s marked with a diamond) the cursor

keys and rotary control are used to scroll all items through the display if the list has more than three items; look, for example at the FUNCTION and UTILITY screens.

In screens where a parameter with a numeric value is displayed the cursor keys move the edit cursor (a flashing underline) thr ough the numeric field and the rotary control will increment or decrement the value; the step size is determined by the position of t he edit cursor within the numeric field.

Thus for FREQUENCY set to 1.000000000 MHz rotating the control will change the frequency in 1kHz steps. The display will auto−range up or down as the frequency is changed,

provided that autoranging permits the increm ent size to be maintained; this will in turn determine the lowest or highest setting that can be achieved by turning the control. In the example above, the lowest frequency that can be set by rotating the control is 1 kHz, shown on the display as

1.000000000 kHz.

This is the limit because to show a lower frequency the display would need to autorange below 1kHz to

xxx.xxxxxxx Hz in which the most significant digit repres ents 100Hz, i.e. the

1kHz increment would be lost. If, however, the starting frequency had been set to

1.000000000 MHz, i.e. a 100 Hz increment, the display would have autoranged at 1kHz to

900.0000000 Hz and could then be decremented down to 100.0000000 Hz without

losing the 100 Hz increment. Turning the control quickly will step numeric values in multiple increments.

Principles of Operation

The instrument operates in one of two different modes depending on the waveform selected. DDS mode is used for sine, cosine, haversine, triangle, s inx/x and ramp waveforms . Clock Synthesis mode (shown as vclk in the status menu) is used for sq uar e, pulse, pulse t rain, and arbitrary.

In both modes the waveform data is stored in RAM. As the RAM address is incremented the values are output sequentially to a Digital−to−Analogue Converter (DAC) which reconstructs the waveform as a series of voltages steps which are subsequently filter ed before being passed to the main output connector.

The main difference between DDS and Clock Synthesis modes is the way in which the addresses are generated for the RAM and the length of the waveform data.

Clock Synthesis Mode

In Clock Synthesis mode the addresses are always sequential (an increment of one) and the clock rate is adjusted by the user in the range 100MHz to 0·1Hz. The frequency of the waveform is clock frequency ÷ waveform length, thus allowing short waveforms to be played out at higher repetition rates than long waveforms, e. g. the maximum frequency of an 8 point waveform is 100e6÷8 or 12·5 MHz but a 1000 point waveform has a maximum frequency of 100e6÷1000 100kHz.

Arbitrary waveforms have a user defined length of 4 t o 65536 points. Squarewaves use a fixed length of 2 points and pulse and pulse train have their length defined by the user selected period value.

DDS Mode

In DDS mode (Direct Digital Synthesis) all waveforms are stored in RAM as 4096 points. The frequency of the output waveform is determined by the rate at which the RAM addresses are changed. The address changes are generat ed as follows:

The RAM contains the amplitude values of all the individual points of one cycle (360º) of the waveform; each sequential address change corresponds to a phase increment of the waveform of 360º/4096. Instead of using a counter to generate seq uent ial RAM addresses, a phase accumulator is used to increment the phase.

On each clock cycle the phase increment, which has been loaded into the phase increment register by the CPU, is added to the current result in the phase accumulator; the 12 most significant bits of the phase accum ulator drive the lower 12 RAM address lines, the upper 4 RAM address lines are held low. The output waveform frequency is now determined by the size of the phase increment at each clock. If each increment is the same size then the output frequency is constant; if it changes, t he out put frequency changes as in sweep mode.

The generator uses a 44 bit accumulat or and a 100 MHz clock f r equency; the frequency setting resolution is 0·1 mHz.

Only the 12 most significant bits of the phase accumulator are used to address the RAM. At a waveform frequency of F

CLK/4096 (~24·4kHz), the nat ur al frequency, the RAM address

increments at every clock. At all frequencies below this (i.e. at smaller phase increments) one or more addresses are output f or m or e than one clock period because the phase increment is not big enough to step the address at every clock . Similarly at frequencies above the natural frequency the larger phase incr em ent c auses s om e addr es ses to be skipped, giving the effect of the stored waveform being sampled; differ ent points will be sampled on successive cycles of the waveform.

♦ ◊ ◊

♦

Function Generator Operation

This section deals with the use of the instrument as a function generator, i.e. generating sine, square, triangle, dc, ramp, haversine, cosine, havercosine and sinx/x waveforms. All but squarewave are generated by DDS which gives 10−digit frequency resolution; squarewave is generated by Clock Synthesis which results in 8−digit freq uency resolut ion. Refer to Principles of Operation in the previous section for a f uller explanation of the differences involved.

The

WAVEFORM FUNCTIONS screen lists all the waveforms that the instrument c an pr oduce

including pulse, pulse-train and arbitrary which are described in detail in their appropriate sections.

Much of the following descriptions of amplitude and offset control, as well as of Mode, Sweep, etc., in following sections, apply to arbitrary waveforms as well as standard f unction generator waveforms; for clarity, any differences of operation with arbitrary, pulse and pulse−train are described only in those sections.

Setting Generator Parameters

Waveform Selection

WAVEFORM FUNCTIONS

sine square triangle

Pressing the FUNCTION key gives the WAVEFORM FUNCTIONS screen which lists all the waveforms available; the rotary control or cursor keys can be used to scr oll the full list back and

forward through the display. The currently selected waveform (sine with the factory defaults setting) is indicated by the filled diamond; the select ion is changed by pressing the soft−key beside the required waveform.

Frequency

Pressing the FREQ key gives the SINE FREQUENCY screen. With freq selected as shown above, the frequency can be entered directly f r om the keyboard in integer, floating point

exponential or direct units format, e.g. 12·34 kHz can be entered as 12340, 12340·00, 1·234 exp 4 or 12.34 kHz etc. However, the display will always show the entry in the most appropriate engineering units, in this case 12·34000000 kHz.

With 123·4µs can be entered as ·0001234 or 123·4e−6; again the display will always show the entry in

the most appropriate engineering units. Squarewave, generated by Clock Synthesis has 8−digit r esolut ion for both frequency and period

entry but the editing method is the same as for DDS generated waveforms.

SINE FREQUENCY 10·00000000 kHz

freq period ◊

period selected instead of freq the f r equency can be set in terms of a period, e.g.

Turning the rotary control will increment or decrement the numeric value in steps determined by the position of the edit cursor (flashing underline); the cursor is moved with the left and rig ht arrowed cursor keys.

Note that the upper freq uenc y limits vary for t he different waveform types; refer to the Specifications section for details. Frequency setting for ar bit r ar y, pulse and pulse−train is explained in the relevant sections; all use Clock Synthesis mode.

♦ ◊

Ω

−

Amplitude

Pressing the AMPL key gives the AMPLITUDE screen. The waveform amplitude can be set in terms of peak−to−peak Volts (Vpp), r.m.s. Volts (Vrms) or

dBm (referenced to a 50Ω or 600Ω load). For Vpp and Vrms the level can be set assuming that the output is open−circuit ( is selected termination is always assumed and the

changed to displayed amplitude values for 600Ω termination tak e t his int o acc ount .

With the appr opr iat e form of the amplitude selected (indicated by the filled diamond) the amplitude can be entered directly from the keyboard in integer, floating point, exponential or direct units format, e.g. 250mV can be entered as ·250 or 250 exp −3, etc., However, the display will always show the entry in the most appropriate engineering units, in this case 250mV.

Alternate presses of the ± key will invert the MAIN OUT output; if DC OFFSET is non−zero, the signal is inverted about the same offset. The exception to this is if the amplitude is specified in dBm; since low level signals are specified in −dBm (0dBm = 1mW into 50Ω = 224mVrms) the

sign is interpreted as part of a new amplitude entr y and not as a command to invert the signal.

Note that for DC, sinx/x, pulse, pulse-tr ain and arbit r ar y amplitude can only be displayed and entered in the Vpp form; further limitations on pulse, pulse−train and arbitrary amplitude ar e discussed in the appropriate sections.

AMPLITUDE: +20·0 Vpp

Vpp Vrms ◊

dBm load:hiZ ◊

load:hiZ) or terminated (load:50

or load:600Ω); when dBm

load:hiZ setting is automatically

load:50Ω. Note that the actual generat or out put impedance is always 50Ω; the

DC Offset

Pressing the OFFSET key gives the DC OFFSET screen. The offset can be entered directly from the keyboard in integer, floating point, exponential or direct units format, e.g. 100mV can be entered as ·1 or 100 exp −3, etc. However, the display will always show the entry in the most

appropriate engineering units, in this case 100mV. During a new offset entry the ± key can be used at any time to set the offset negative; alternate presses toggle the sig n between + and −.

Turning the rotary control will increment or decrement the numeric value in steps determined by the position of the edit cursor ( flashing underline); the cursor is moved by the left and right arrowed cursor keys. Because DC offset can have negative values, the rotary contr ol can tak e the value below zero; although the display may autorange to a higher resolution if a step takes the value close to zero, the increment size is maintained correctly as the offset is stepped negative. For example, if the display shows

program = +205· mVdc with the cursor in the most significant dig it , the rotary control will decrement the offset in 100mV

steps as follows: program = +205· mVdc

program = +105· mVdc program = +5·00 mVdc

program = −95·0 mVdc program = −195· mVdc

DC OFFSET: program +0·00 mVdc (actual +0·00 mVdc)

load:hiZ ◊

The actual DC offset at the MAIN OUT socket is att enuat ed by the fixed−step output attenuator when this is in use. Since it is not obvious when the signal is being attenuated the actual offset is shown in brackets as a non−editable field below the programmed value.

For example, if the amplitude is set to 2·5Vpp t he out put is not attenuated by the fixed attenuator and the actual DC offset (in brackets) is t he same as that set. The

DC OFFSET: program +1.50 Vdc (actual +1.50 Vdc)

load: hiZ ◊

If the amplitude is now reduced to 250mVpp which introduces the att enuat or, the actual DC offset changes by the appropriate factor :

DC OFFSET: program +1.50 Vdc (actual +151. mVdc)

load: hiZ ◊

The above display shows that the set DC offset is +1·50V but the actual offset is +151mV. Note that the actual offset value also takes into ac count the true attenuation provided by the fixed attenuator, using the values determined during the calibration procedure. In t he example displayed the output signal is 250mVpp exactly and takes account of the small error in the fixed attenuator; the offset is 151.mV exactly, taking account of the effect of the known attenuation (slightly less than the nominal) on the set offset of 1·50V.

DC OFFSET display shows:

Whenever the set DC offset is modified by a change in output level in this way a warning message that this has happened will be displayed. Similarly, because the DC offset plus signal peak is limited to ± 10V to avoid waveform clipping, a warning messag e will be displayed if this condition is set. This is explained more fully in the Warnings and Error Messages sec t ion.

The output attenuation is controlled intelligent ly to minimise the difference between the programmed and actual offset when the combinat ion of programmed amplitude and offset allows this. Thus when the offset is set to 150mV, for example, the amplitude can be reduced to nominally 50mVpp before the fixed attenuator causes the actual offset to be different from the programmed value.

Warnings and Error Messages

Two classes of message are displayed on the screen when an illegal combination of parameters is attempted.

WARNING messages are shown when the entered setting caus es s om e change which the user might not necessarily expect. Examples are:

1. Chang ing the amplitude from, for example, 2·5 Volts pk−pk to 25mV pk−pk brings in the step attenuator; if a non−zero offset has been set then this will now be attenuated too. The message on the screen but the setting will be accepted; in this case t he ac t ual, at tenuated, offset will be shown in brackets below the set value.

2. With the output level set to 10V pk −pk, increasing the DC offset beyond ± 5V will cause the message

change will be accepted (producing a clipped waveform) and the user may then choose t o change the output level or the offset t o pr oduce a s ig nal which is not clipped.

(clip?) will show in the display beside AMPLITUDE or DC OFFSET while the

clipped condition exists.

DC offset changed by amplitude will be shown temporarily

Offset + Sum + level may cause clipping. The offset

◊ ◊

◊

ERROR messages are shown when an illegal setting is attempted, mos t generally a number outside the range of values permitted. I n t his c ase t he entry is rejected and the parameter setting is left unchanged. Examples are:

1. Entering a frequency of 1MHz for a triangle waveform . The error m es sage:

Frequency out of range for the selected waveform is shown.

2. Entering an amplitude of 25Vpp. The error message:

Maximum output level exceeded is shown.

3. Entering a DC offset of 20V. The error message:

Maximum DC offset value exceeded is shown.

The messages are shown on the display for approximately two seconds. The last two messages can be viewed again by pressing the System Operations section.

Each message has a number and the full list appear s in Appendix 1. The default set−up is f or all warning and err or messages to be displayed and for a beep to sound

with each message. This set−up can be changed on the screen. The

error menu is shown below:

error beep: ON error message: ON

warn message: ON

last error... soft−key on the UTILIT Y screen, see

error... menu on the UTILITY

warn beep: ON

Each feature can be turned ON and OFF with alternat e pr es ses of the associated soft−key; t he factory default is for all features to be ON.

SYNC Output

SYNC OUT is a multifunction CMOS/TTL level output that can be automatically or manually set to be any of the following:

• waveform sync : A square wave with 50% duty cycle at the main waveform frequency, or a pulse coincident with the first few points of an arbitrary waveform. Can be selected for all waveforms.

• burst done : Produces a pulse coincident with the last cycle of the burst.

• trigger : Selects the current trigger signal (internal, external or manual).

Useful for synchronising burst or gated signals.

• sweep sync : Out puts t he s weep trig ger and sweep marker signals.

• phase lock : Used to lock two or more generators. Produces a positive edge at

the 0º phase point.

The setting up of the s ig nals t hemselves is discussed in the relevant sections later in this manual, e.g.

trigger is described in the Triggered Burst/Gate section. Pres sing the SYNC OUT key

calls the

SYNC OUT setup screen.

SYNC OUT:

output: on

mode: auto

src: waveform sync

SYNC OUT is turned on and off by alternate presses of the output soft−key.

The selection of the signal to be out put from the SYNC OUT socket is made using the src (source) soft−key; repeated presses of src cycle the selection through all the choices

waveform sync, burst done, etc.) listed above. Alternatively, with the src selected

( (double−headed arrow) the rotary control or cursor keys can be used to step backwards and

forwards through the choices. The source selection of the SYNC OUT waveform can be made automatic (

user−defined ( SYNC OUT waveform most appropriate for the curr ent main waveform is selected.

For example,

manual) with alternate presses of the mode soft−key. In automatic mode the

waveform sync is automatically selected for all continuous waveforms, but

auto) or

trigger is select ed in trigger or gated waveform modes. The automatic selection will be

mentioned in each of the appropriate main waveform m ode s ections and a full table is given in Appendix 2.

The automatic selection can still be changed manually by the mode has been selected but the selection will immediately revert to the automatic choice as s oon

as any relevant parameter (e.g. main waveform f r equency or amplitude) is adjusted. must be selected by the mode soft−key for a source other than the automatic choice to r em ain set. The

auto selection will generally set the most frequently used signal, e.g. waveform

src soft−key even when auto

Manual

sync for all continuous main waveforms, but manual will need to be used for special

requirements.

◊ ◊

General

Principles of Sweep Operation

All standard and arbitrary waveforms can be swept with the exception of pulse and pulse−train. During Sweep all waveforms are generated in DDS mode because this offers the s ig nificant advantage of phase−continuous sweeps over a very wide frequency range (up to 10 it must be remembered that t he frequency is actually stepped, not truly linearly swept, and thought needs to be given as to what the instrument is actually doing when using extreme combinations of sweep range and time.

For DDS operation during Sweep all waveforms must be 4096 points in length; this is the natur al length for standard waveforms but all arbitr ary waveforms are expanded or condensed in software to 4096 points when Sweep is turned on. This does not affect the original data.

Sweep Operation

). However,

Sweep mode is turned on and off either by the screen accessed by pressing the SWEEP front panel key, or by the sweep soft−key on the

on or off soft−key on the SWEEP SETUP

MODE screen.

When sweep is turned on the sof t ware creates a table of 2000 frequencies between, and including, the specified start and stop values. Because any frequency used in sweep mode must be one of the tabled values, the centre frequency displayed (see Sweep Range) may not be the exact mid−point and markers (see Sweep Marker) may not be exactly at the pr ogrammed frequency. The frequency resolution of the steps will be particularly coarse with wide sweeps.

Connections for Sweep Operation. Sync Out and Trig In

Sweeps are generally used with an oscilloscope or hard−copy device to investigate the frequency response of a circuit. The MAIN OUT is connected to the circuit input and the c irc uit output is connected to an oscilloscope or, for slow sweeps, a recorder.

An oscilloscope or recorder can be trigger ed by connecting its trigger input to the g ener at or’s SYNC OUT; S YNC OUT defaults to

goes low at the start of sweep and high for t he dur ation of the last frequency step at the end of sweep; depending on the sweep time set this should be long enough for an os cilloscope to retrace, for example.

To show a marker on the display instrument the SYNC OUT can be set to additionally output a marker pulse. See Sweep Marker section for s et t ing marker frequency.

For triggered sweeps, a trigg er signal may be provided by any of the possible trigger sources, i.e. internal, external, manual or remot e.

sweep sync when sweep is turned on. sweep sync

The generator does not provide a ramp out put for use with X−Y displays or recorders.

Setting Sweep Parameters

Pressing the SWEEP key (or the sweep setup soft−key on the MODE screen) displays the

SWEEP SETUP screen.

SWEEP SETUP: off

marker… ◊

range… type… ◊ time… spacing… ◊

♦ ◊ ◊

◊ ◊

Menus for setting up the range, time (sweep rate), type (continuous, trigg ered, etc.) spacing (lin/log) and marker position are all access ed from this screen using the appropriate s of t−key. In addition Sweep Mode itself is turned on and off with alternate presses of the

soft−key; sweep can also be turned on by the sweep soft−key on the MODE screen. On all the following menus, pressing the done screen.

Sweep Range

Pressing the range... soft−key calls the SWEEP RANGE screen.

The maximum sweep range for all waveforms is 1mHz to 40MHz, including triangle, r am p and squarewave which have different limits in unswept operation.

Sweep range can be defined by start and stop freq uencies or in t er ms of a centre frequency and span. directly from the keyboard or by using the rotary control; the start frequency must be lower than the stop frequency (but see Sweep Type for selecting sweep direction).

on/off

soft−key returns the display to this SWEEP SETUP

SWEEP RANGE:

start: 100·0 kHz stop: 10·00 MHz centr/span done ◊

Start and Stop soft−keys permit the two end points of the sweep to be set

Pressing the frequency and sweep span about that frequency; pressing the start/stop soft−key on that screen returns the display to the start and s t op frequency form of ent ry.

Note that when the sweep is displayed in terms of centre frequency and span the span will always be the exact difference between start and stop frequencies but t he c ent r e frequency shown will be that of the frequency step nearest t he t r ue c ent r e frequency, see Principles of Sweep Operation section.

Sweep Time

Pressing the time... soft−key calls the SWEEP TIME screen.

The sweep time can be set from 1ms t o 999s with 3−dig it r esolut ion by direct keyboard entry or by using the rotary control.

Sweep Type

Pressing the type soft−key calls the SWEEP TYPE screen.

centr/span soft−key changes the screen t o per mit entry in terms of centr

SWEEP TIME: 0·05 sec

done ◊

SWEEP TYPE:

continuous direction: up sync: on done ◊

This screen is used to set the sweep mode (continuous; t riggered; triggered, hold and reset) and sweep direction.

start frequency to stop frequency.

down

stop frequency to start frequency.

up/down

start frequency to stop frequency and back to start f r equency.

down/up

stop frequency to start frequency and back to stop frequency.

♦ ◊

Successive presses of the direction soft−k ey select one of the following sweep directions:

The total sweep time is always that set on the SWEEP TIME screen, i.e. for up/down and

down/up operation the sweep time in each direction is half the total. Similarly the total number

of steps is the same for all choices, i. e. there will be half the number of steps in each direction for

up/down and down/up operation. In the sweep mode descriptions which follow the

direction is assumed to be In

continuous mode the generator sweeps continuously between the start and stop

frequencies, trig gered repetitively by an internal trigger generator whose f r equency is determined by the sweep time setting. At the stop frequency the generator r esets t o the start frequency and begins a new sweep. If

immediately from the stop f r equency to zero frequency (i.e. it does not dwell at the stop frequency for the full step interval) and then starts the next sweep from the fir st point of the waveform, synchronised to the (internally generated) t rigger signal.

This is useful because the sweep always starts from the same point in the waveform but the waveform discontinuity can be undesirable in some circumstances, e.g. filter evaluation. With

up but all modes can be used with all sweep directions.

sync is set to on (the default) the generator actually steps

sync set to off, the freq uency steps direct ly and phase continuously f r om t he s t op frequency

to the start frequenc y (after dwelling at the Stop frequency for the full step interval) but is not synchronised to the software−generated t r ig ger signal.

triggered mode the generator holds the output at the start frequency until it recognises a

In trigger. When triggered, the frequency sweeps to the stop f r equency, r esets, as follows, and

awaits the next trigger. If waveform) and starts a new sweep at the first point of the waveform when the next tr igger is

recognised. If frequency until the next trigg er initiates a new sweep.

trig’d,hold/reset mode the generator holds the output at the start frequency until it

In recognises a trigger; when triggered, the frequenc y sweeps to the stop frequency and holds. At

the next trigger the output is r es et t o the start frequency where it is held until the next sweep is initiated by a further trigg er. If

above; if new sweep at the first point of the waveform.

For triggered sweeps, a trigg er signal may be provided by any of the possible trigger sources, i.e. internal, external, manual or remot e.

The generator does not provide a ramp out put for use with X−Y displays or recorders.

Sweep Spacing

Pressing the spacing... soft−key on the SWEEP SETUP scr een c alls the SWEEP

SPACING screen.

sync if set to on the frequency resets to zero frequency (i.e. no

sync is set to off the waveform resets to the start f r equency and runs at that

sync is set to off the output operates exactly as described

sync is set to on the frequency actual g oes t o zero at t he s tart and begins each

SWEEP SPACING:

logarithmic

linear

done ◊

With linear selected the sweep changes the frequency at a linear rate; with logarithmic selected the sweep spends an equal time in each frequency decade.

Sweep Marker

A sweep marker pulse is also available from the SYNC OUT socket when sweep sync (the default condition) is selected. The marker pulse is differentiated from the sweep sync pulse by

being approximately half the amplitude of the sync pulse; t his per m its the trigger level of the display oscilloscope to be adjusted for the sweep sync pulse without additionally triggering on the marker pulse.

The marker pulse fr equency is set from the the

marker... soft−key on the SWEEP SETUP screen.

SWEEP MARKER FREQ: progrm: 5·000 MHz actual: 4·977 MHz

done ◊

A new marker frequenc y can be programmed directly from the keyboard or by using t he r otar y control and cursor keys. Note that the marker frequency can only be one of t he values in the sweep frequency table; any value in the sweep range can be entered but the actual value will be the nearest frequency in the table. When sweep is turned on, the actual marker frequency is shown in the non−editable field below the programmed freq uency. For the default sweep setting of 100kHz to 10MHz in 50ms, the actual frequency of a 5MHz marker is 4·998 MHz.

The marker duration is Sweep time/2000, i. e. the dwell time at a single frequency step. To avoid displaying a sweep marker, the marker frequency is simply set to a value outside the

current sweep frequency range.

SWEEP MARKER FREQ menu, called by pressing

♦ ◊ ◊

◊ ◊ ◊

General

Triggered Burst and Gated modes are selected from the MODE screen, called by the MODE key, as alternatives to the default continuous mode.

In Triggered Burst mode a defined number of cycles are generated following each trigger event. This mode is edge trigger ed.

In gated mode the generat or r uns whenever the gat ing signal is true. This mode is level sensitive. Triggered Burst mode can be controlled by either the Int er nal Trigger Generat or, an external

trigger input, by the f r ont panel MAN TRIG key or by remote control. Gated mode can be controlled by the Internal Trigger Generator or on external trig ger input.

In both modes the start phase, i.e. the starting point on the waveform cycle, can be specified.

Internal Trigger Generator

Triggered Burst and Gate

MODE:

continuous gated setup…◊ triggered setup…◊

The period of the Internal Trigger Generat or is set with the period soft−key on the

TRIGGER IN set-up screen called by the TRIG IN key.

source: int force ◊

slope : positive

level: +1·4 V

period: 1·00ms

The Internal Trigger Generator divides down a crystal oscillator to produce a 1:1 square wave with a period from 0·01ms (100kHz) to 200s ( ·005Hz). Generator period entries that cannot be exactly set are accepted and rounded up to the nearest available value, e.g. ·109m s is r ounded to ·11ms.

When Triggered Burst or Gated modes are selected the SYNC OUT source automatically defaults to

triggering or g at ing is specified. In Triggered Burst mode the selected edge of each cycle of the trigger generator is used to

initiate a burst; the interval between bursts is therefore 0·01ms to 200s as set by the generator period.

In Gated mode the output of the main generator is gated on whilst the Internal Trigger Generat or output is true; the duration of the gate is therefore ·005m s t o 100s in step with trigger generator periods of ·01ms to 200s.

trigger which is the output of the internal trigger generator when internal

External Trigger Input

External trigger or gat e signals are applied to the front panel TRIG IN socket which has a variable threshold level set using the

direct keyboard entry or by using the rotary control. I n Triggered Burst mode the input is edge sensitive; the selected edge of each external tr ig ger initiates the specified burst. In Gated mode the input is level sensitive; the output of the main gener at or is on whilst the gate signal is true.

The minimum pulse width that can be used with TRIG IN in Triggered Burst and Gated mode is 50ns and the maximum repetition rate is 1MHz. The maximum signal level that can be applied without damage is ±10V.

level soft-key; the level can be set from –5·0V to +5·0V by

◊ ◊ ◊

♦ ◊

When Triggered Burst or Gated modes are selected the SYNC OUT source automatically defaults to signal when external triggering or gat ing is specified.

trigger which is always a positive−edged version of the external trigger or gate

Triggered Burst

Triggered Burst mode is turned on with the triggered soft−key on the MODE screen. The setup… soft−key on this screen accesses t he which the burst count and start phase are set. The other tr igger parameters are set on the

TRIGGER IN setup screen called by pressing the TRIG IN key.

Trigger Source

The trigger source c an be select ed with the source soft−key on the TRIGGER IN setup screen to be

int, ext or man.

TRIGGER/GATE SETUP screen on

source: int force ◊

slope: positive level: +1·4 V period: 1·00ms

With up as described in the previous section.

With With

be used to initiate a burst.

int selected the internal trigger generator is used to initiate a burst; this g ener ator is set

ext selected the specified edge of t he signal at TRIG IN is used to initiate a burst.

Trigger Edge

The slope soft−key is used to select the edge ( positive or negative ) of the external trigger signal that is used to initiate a burst. The default setting of positive should be used for trigger ing by the Internal Trigger Generator.

Note that the triggered burst on an oscilloscope for example, is always positive−going at the start of the burst.

Burst Count

The number of complete cycles in each burst following the trigger is set fr om the

TRIGGER/GATE SETUP screen called by pressing setup on the MODE screen.

man selected as the source only pressing the MAN TRIG key or a remote command can

trigger signal from SYNC OUT, used for synchronising the display of a

TRIGGER/GATE SETUP:

burst cnt: 0000001

phase: +000·0º

(actual: +000·0º)

The required count can be set by pressing the burst cnt soft−key followed by direct entries from the keyboard or by using the rotary control. The maximum number of waveform cycles that can be counted is 1048575 (2

−1).

Start Phase

The start phase, i.e. the point on the waveform cycle at which the burst starts, can be selected by pressing the rotary control. Since the waveform cycle is always completed at the end of the burst the start phase is also the stop phase.

phase soft−key followed by direct entries from the keyboard or by using the

Waveform

Max Wfm Freq

Phase Control Range & Resolution

± 360°, 0·1°

◊ ◊ ◊

The phase can be set with a precision of 0·1° but the actual resolution is limited with some waveforms and at certain waveform frequencies as detailed below. To indicate when this is the case the actual phase is shown in brackets as a non−editable field below the programm ed value.

To achieve start phase precision all waveforms are run in Clock Synthesis mode, i.e. as if they were arbitrary waveforms, when Triggered Burst is specified; this limits actual frequency resolution to 8 digits for all waveforms although the normally DDS generated waveforms are still entered with 10−digit precision. Sine/cosine/haversine/etc. waveform s are created as if they were arbitrary waveforms with the first point of the waveform exactly at the start phase; each time the phase or frequency is changed t he waveform is r ec alculat ed which can cause a slight lag if these parameters are being changed q uickly with the rotary knob.

The phase resolution of true arbit r ar y waveforms is limited by the waveform length since the maximum resolution is 1 clock; thus waveforms with a length > 3600 points will have a resolution of 0·1° but below this number of points the maximum resolution becomes 360° ÷ number of points.

Square waves, pulse and pulse train have no start phase adjustment; phase is fixed at 0°. A summary of start phase capabilities in Triggered Burst mode is shown in the table below:

Sine, cosine, haversine, havercosine 2·5MHz Square 2·5MHz Triangle 500kHz Ramp 500kHz Sin(x)/x 500kHz Pulse & Pulse Train 10MHz Arbitrary 100MS/s clock

Gated Mode

Gated mode is turned on with the gated soft−key on the MODE screen. The setup... soft−key on this screen accesses the phase is set. The other parameters associated with Gated are set on the setup screen called by pressing the TRIG IN key.

Gate Source

TRIGGER/GATE SETUP screen on which the start

source: int force ◊

slope: positive level: +1·4 V period: 1·00ms

0° only

± 360°, 0·1° ± 360°, 0·1° 0° only ± 360°, 360 ÷ length or 0·1°

TRIGGER IN

The gate signal source can be selected with the source soft−key on the TRIGGER IN setup screen to be int or ext.

With the gate is half the g ener ator period, see Internal Trigger Generator section.

With the signal at TRIG IN until the same level on the opposite edge; t he t hreshold and edge are set

using the

int selected the internal trigger generator is used to gate the waveform; the duration of

ext selected the gate duration is fr om the threshold level set on the specified edge of

level and slope soft-keys respectively.

♦ ◊

Gate Polarity

If slope on the TRIGGER IN setup screen is set to positive the gate will open at the threshold on the rising edge and close on t he t hreshold of the falling edge of an exter nal

gating signal, i.e. the gate signal is true when the TRIG IN signal is high. If the

negative the gate signal is true when the TRIG IN signal is low. The default setting of

positive should be used for gating with the Inter nal Trigger Generator.

Start Phase

Press setup... on the MODE screen to access the TRIGGER/GATE SETUP screen on which the start phase can be set.

The start phase, i.e. the point on the waveform cycle at which the gated waveform starts, can be selected by pressing the using the rotary control. Since the waveform cycle is always completed at the end of t he gated period the start phase is also the stop phase.

slope is set

TRIGGER/GATE SETUP:

BURST CNT: 0000001

PHASE: +000·0°

(actual: +000·0°)

phase soft−key followed by direct entries from t he keyboard or by

The phase can be set with a precision of 0·1° but t he actual resolution is limited with some waveforms and at certain waveform frequencies as detailed below. To indicate when this is the case the actual phase is shown in brackets as a non−editable field below the programm ed value.

To achieve start phase precision all waveforms are run in Clock Synthesis mode, i.e. as if they were arbitrary waveforms, when Gated mode is specified; this limits actual frequency resolution to 8 digits for all waveforms although the nor m ally DDS generated waveforms are still entered with 10−digit precision. Sine/cosine/haversine/etc. waveforms ar e c r eat ed as if they were arbitrary waveforms with the first point of the waveform exactly at the start phase; each time the phase or frequency is changed the waveform is r ec alcul at e which can cause a slight lag if these parameters are being changed quickly with the rotary knob.

Square waves, pulse and pulse trains have no start phase adjustment; phase is fixed at 0°. Refer to the table in the Triggered Burst section for a sum m ary of start phase capabilities.

Sync Out in Triggered Burst and Gated Mode

When Triggered Burst or Gated modes are selected the SYNC OUT source automatically defaults to trigger used whether internal (from the Internal Trigger Generator) or external of either polarity.

trigger; trigger is a positive−edged signal synchronised to t he actual

Alternatively, SYNC OUT can be set t o sync out then provides a signal which is low while the waveform is running and high at all other

times.

burst done on the SYNC OUT setup screen;

◊ ♦ ◊

General

In Tone mode the output is stepped through a user−defined list of up t o 16 frequencies under the control of the signal set by the signal can be the Internal Trigger Generator, an external trigger input, the front panel MAN TRIG key or a remote command.

All standard and arbitrary waveforms can be used in Tone mode with the exception of pulse and pulse−train. During Tone all waveforms are generated in DDS mode for fast phase−continuous switching between frequencies. For DDS operation all waveforms must be 4096 points in lengt h; this is the natural length for s tandard waveform s but all arbit r ar y waveforms ar e expanded or condensed in software to 4096 points when the Tone list is built. This does not affect t he original data.

Because DDS mode is used the frequency range for all waveforms is 1mHz to 10MHz in Tone mode, including triangle, ramp and squarewave which have different limits in continuous operation.

Tone Frequency

Press the tone setup... soft−key on the MODE screen, c alled by pressing the MODE key, to get the

Tone Mode

source soft−key on the TRIGGER IN setup screen. This

TONE setup screen:

Each frequency in the list can be changed by pressing the appropriate soft−key and entering t he new value from the keyboard. The selected frequency can be deleted from the list by pressing the

selecting the keyboard.

The whole list can be scrolled back and forward through t he display using t he r otar y contr ol.

Tone Type

The type soft−key on the TONE setup screen per m its three types of tone switching to be specified.

With specified in the completing the last cycle of the curr ent frequency.

With field goes to the level specified in the continues until the level changes again at which point the current cycle is completed; t he out put

is then gated off until the next occurrenc e of the gating signal at which time the next frequency in the list is gated on. The difference between triggered and gated tone changes is therefore that in triggered mode the sig nal changes phase−continuously from one freq uenc y to t he next at t he waveform zero−crossing point immediately after t he t rigger signal whereas in gated mode there can be an ‘off’ period between successive frequencies whilst the gate signal is not t rue.

TONE type: trig◊

2·000000 kHz #2

3·000000 kHz del◊ end of list #4

del (delete) soft−key. Additional frequencies can be added to the end of the list by

end of list with the appropriate soft−key and entering t he new f r equency from

type set to trig the frequency changes af ter each occurrence of the signal edge

source and slope fields on the TRIGGER IN screen but only after

type set to gate the frequency chang es when the sig nal specified in the source

slope field on the TRIGGER IN screen and

With at each occurrence of the sig nal edg e s pecified in the

type set to fsk the freq uency chang es instantaneously (and phase−continuously)

source and slope fields on the

TRIGGER IN screen without completing the current waveform cycle; this is tr ue FSK

(Frequency Shift Keying) tone switching.

<lowest tone frequency.

TRIGGER:

Maximum tone frequency 50kHz; maximum switching frequency 1MHz.

FSK:

Maximum tone frequency 1MHz; maximum switching frequency 1MHz.

The following diagrams demonstrate the differences between trigger, gate and FSK tone switching for a list of 2 f r equencies switched by a square wave (positive slope specified on TRIGGER IN setup).

The maximum recommended tone f r equencies and trigger/gate switching frequencies for the three modes are as follows:

GATE:

Maximum tone frequency 50kHz; maximum switching frequency

Tone Switching Source

The signal which controls the frequency switching is that set by the source soft−key on the

TRIGGER IN setup screen. The slope field on the same screen sets the ac t ive polarity of

that signal; when set to level of the gating signal is true and the reverse is true for a that can be selected by the external trigger input, the front panel MAN TRIG key or a remote command. A full explanation for

each of these can be found in the Triggered Burst and G at e c hapt er.

positive the rising edge of the trigger signal is active or the high

source soft−key can be the Internal Trigger Generat or, an

DTMF Testing with Two Generators

An important use of Tone mode is DTMF (Dual Tone Multiple Frequency) testing in which 2 instruments are set up with equal length lists of different frequencies and are trig gered from a common external signal. The outputs are summed tog et her us ing the external SUM capability, see the Sum chapter. DTMF testing generally uses sinewaves in the frequency range 600Hz to 1·6kHz.

negative setting. The signal

◊ ◊ ◊

◊ ♦ ◊

Introduction

Arbitrary (Arb) waveforms are generated by sequentially addressing the RAM containing the waveform data with the arbitrary clock. The frequency of the arb waveform is determined both by the arb clock and the total number of data points in the cycle.

In this instrument an arb waveform can have up to 65536 horizontal points. The vertical range is

−2048 to +2047, corresponding to a maximum peak−peak output of 20 Volts. Four waveforms can be specified and they are listed at the bottom of the

The four arbs have names (arb1, arb2,arb3, and arb4) which cannot be changed. As it is not possible to delete these arbs a new instrument has four default arbs installed each 1000 points long. Each arb has its current length specifies on the

shown above. Arb waveforms can be created using the supplied waveform design s of t ware that enables the

user to create waveforms fr om m at hematical expressions, from combinations of ot her waveforms, or freehand on a pc, see Appendix 4. These waveforms may then be downloaded to the instrument via one of the remot e control interfaces.

Arbitrary Waveform Generation

WAVEFORM FUNCTIONS screen.

WAVEFORM FUNCTIONS

pulse-train setup…◊ arb1 1000 points arb2 1000 points

WAVEFORM FUNCTIONS screen as

Arb Waveform Terms

The following terms are used in describing ar b waveform s:

• Horizontal Size. The number of horizontal points is the time component of the waveform. The minimum size is 4 points and the maximum is 65536 points.

• Waveform Address. Each horizontal point on an arb waveform has a unique address. Addresses always start at 0000, thus the end address is always one less than the horizontal size.

• Arb Frequency and Waveform Frequency. The arb frequency is the clock rate of the data RAM address counters and has a range of 0· 1Hz to 100MHz (internal clock) or DC t o 50MHz (external clock) on this instrument. The waveform frequency depends on both the arb frequency and horizontal size. A 1000 point waveform clock ed at an ar b frequency of 100MHz has a waveform frequency of 100e6÷1000 = 100kHz.

• Data Value. Each point in the waveform has an amplitude value in the range −2048 to +2047.

• Arb Waveform Amplitude. When playing arb waveforms the maximum output amplitude will

depend on both the range of data values and the output am plitude setting. A waveform that contains data values ranging from −2048 to +2047 will produce a maximum output which is 100% of the programm ed peak−to−peak amplitude; if the maximum r ange of the data values is only −1024 to +1023, for example, t he m aximum out put will only be 50% of the programmed level.

Selecting and O utputting Arbitrary Waveforms

From the WAVEFORM FUNCTIONS screen the rotary knob or cursor keys can be used to scroll the list forwards through the display. Select the required arb waveform by pressing the

associated soft-key.

WAVEFORM FUNCTIONS

pulse-train setup…◊

arb1 1000 points

arb2 1000 points

♦ ♦

♦

◊

Frequency and Amplitude Control with Arbitrary Waveforms

Frequency and Amplitude control work in essentially the same way as for standard waveforms with the following differences.

Frequency

Pressing the FREQuency key with an arbitrary waveform selected calls the ARB FREQUENCY screen:

ARB FREQUENCY 100·00000 MHz

sample waveform ◊ freq period ◊

Arbitrary mode uses Clock Synthesis generation, see Pr inciples of Operation section, which has a setting resolution of 8 digits.

Frequency can be set in terms of frequency or period as for standard waveforms by pressing t he

freq or period soft−key respectively. Additionally, for arbitrary waveforms, frequency/

period can be set in terms of the sam ple clock frequency, by pressing the or in terms of the waveform frequency, by pressing the between them is

waveform frequency = sample frequency ÷ waveform size.

sample soft−key,

waveform soft−key. The relationship

Frequency/period entries are made direct from the keyboard or by using the rotary control in the usual way.

Amplitude

Pressing the AMPLitude key with an arbitrary waveform selected calls the AMPLITUDE screen.

AMPLITUDE: +20·0 Vpp

Vpp

load:hiZ ◊

This differs from t he AMPLITUDE s cr een for standard waveforms in that amplitude can now only be entered in volts peak−to−peak.

Note that the peak−to−peak am plitude set will only actually be output if the arbitrary waveform has addresses with values which reach −2048 and +2047; if the maximum value range is −1024 to +1023 for example then the maximum peak−to−peak voltage will only be 10Vpp for the instrument set to 20Vpp.

Sync Out Settings with Arbitrary Waveforms

The default setting for Sync Out when arbitrary waveforms are selected is waveform sync; this is a pulse that starts coincident with the first point of the waveform and is a few points wide.

Output Filter Setting

The output filter type is automatically chosen by the software to give the best signal quality for the selected waveform. The choice can, however, be overridden by the user and this is most probably a requirement with arbitrary waveforms.

To change the filter, press the FILTER key to call the FILTER SETUP screen.

FILTER SETUP

mode: auto

type: 40MHz eliptic

The default mode is auto which means that the soft ware selects the m ost appropriate filter. With the setting on automatic selection as soon as any relevant parameter is changed. To override the automatic choice press the

auto the type can be changed manually but the choice will revert to the

mode soft−key to select manual.

The three filter choices, which are either automatically selected or set manually with the soft−key, are as follows:

• 40MHz elliptic: The automatic choice for sine, c osine, haversine, havercosine, sinx/x and triangle. Would be the bett er choice for arb waveforms with an essentially sinusoidal content.

• 20MHz Bessel: The automatic choice for positive and negative ramps, arb and sequence.

• No filter: The automatic choice for squarewave, pulse and pulse−tr ains. May be the

better choice for arb waveform s with an essentially rectangular c ont ent .

type

◊

Pulse and pulse−trains are both selected and set−up from independent menus on the

WAVEFORM FUNCTIONS screen called by pressing the FUNCTION key. Pulse and

pulse−trains have similar timing set−ups and considerations but pulses ar e only unipolar, with a maximum amplitude of 10Vpp, whereas pulse−trains can be bipolar, with a maximum peak−to−peak of 20Vpp.

Pulse Set-up

Pulse waveforms are turned on with the pulse soft−key on the WAVEFORM FUNCTIONS screen; pressing the screens:

The pulse period can be set between 40·00ns and 100s, with 8−digit resolut ion, by direct ent ries from the keyboard or by using the rotary control. Pressing the width screen:

Pulse and Pulse-trains

setup... soft−key beside pulse calls the first of the pulse set−up

Enter pulse period:

100·00000 us 10000pts*10.000000ns

exit next ◊

next soft−key calls the pulse

Enter pulse width: program 50·000000 us actual 50·000000 us

exit next ◊

The width can be entered directly from the keyboard or by using t he rotary control. Any value in the range 10·00ns to 99·99s can be programmed but the

the considerations discussed below; for this reason the

actual value may differ because of

actual pulse width is shown below the

program width.

Pressing the

This is very similar to the pulse width screen and, again, the actual delay is shown below

program delay. The delay value that can be entered must be in the range ± (pulse

the period −1 point); positive values delay the pulse output with respect to waveform sync from

SYNC OUT; negative values cause the pulse to be out put before the waveform sync. Pressing the

done soft−key on this screen returns the display to the WAVEFORM FUNCTIONS screen.

next soft−key calls the pulse delay screen:

Enter pulse delay: progrm +0·0000000 ns actual +0·0000000 ns

exit done ◊

The means by which pulse period is set−up in the hardware requires an understanding because it affects the setting resolution of both pulse width and delay. Pulse is actually a particular form of arbitrary waveform made up of between 4 and 100,000 points; each point has a minimum time of 10·00ns corresponding to the f as t est clock frequency of 100MHz.

◊

♦

◊

At short pulse periods, i.e. only a few points in the waveform, the period set t ing resolution is, however, much better than 10·00ns because the t ime−per−point is adjusted as well as the number of points; since the pulse width and delay are also defined in terms of the same point time, varying the time−per−point aff ec ts t heir resolution. For example, if the period is set to 200ns, the minimum pulse width, when set to 10·00ns, will actually be 10·00ns; 20 points at 10·00ns each exactly define the 200ns period. However, if the period is set to 199·0ns, 20 points at the minimum point time of 10· 00ns will be too long so 19 points are used and the point time is

adjusted to 10.473684ns (199·0 changing the pulse width and delay.

For periods above 1·00ms the maximum number of points in the waveform ( 100,000) becomes the factor determining pulse width and delay resolution. For example, with the period set t o 100ms, the smallest pulse width and delay increment is 1µs (100ms÷100,000). This may appear

to cause significant “error s ” at extr em e s et tings (e.g. setting 10ns in t he above example will still give an actual width of 1µs) but in practical terms a 1 in 100,000 resolut ion ( 0· 001% ) is quite acceptable.

Pulse period can be adjusted irrespective of the pulse width and delay setting (e.g . can be set smaller than the programmed pulse width) because, unlike a c onventional pulse gener ator, pulse width and delay are adjusted proportionally as the period is changed. For example, if, from the default pulse settings of 100µs per iod/ 50µs width, the period is chang ed to 60µs the pulse width

÷19); 10.473684ns is now the increment size used when

actual changes to 30µs even though the program width is still 50µs; to get a 50µ s width

with the period at 60µs the width must be re−entered as 50µs after the period has been changed. Period can also be changed from the

key with Pulse mode selected.

The new setting can be entered either as a period in the way already described or as a fr equency by first pressing the is slightly different from changing period on the this screen the number of points in the waveform is never chang ed (just as with a true arb) which means that the shortest period/ highest frequency that can be set is number of waveform points x10·00ns. To achieve faster frequencies (up t o t he s pecification limit) the period must be changed from the pulse set−up screen; changing the frequency f r om the pulse set-up screen causes the number of points to be reduced as the period is reduced ( for periods <1ms).

Pulse-train Setup

Pulse−trains are turned on with the pulse-train soft-key on the WAVEFORM

FUNCTIONS screen; pressing the setup... soft-key beside pulse-train calls the

first of the set up sc r eens:

PULSE PERIOD screen called by pressing the FREQ

PULSE PERIOD: 100·00000 us

freq period

freq soft−key. However, changing the period/frequency from this sc r een

pulse setup screen. W hen c hanging from

Enter no of pulses in train (1-10): 2

done next ◊

◊

♦ ◊

◊

The number of screens used for the setup depends on the number of pulses in the pulse−train. The first three scr eens define the parameters that apply to the whole pattern (number of pulses , overall pulse−train period and baseline voltage); subsequent screens define the pulse level, width and delay for each pulse in turn (3 screens for pulse 1, then 3 screens for pulse 2, etc.). Pr es sing

next on any screen calls the next setup screen, finally returning t he display to the WAVEFORM FUNCTIONS screen from which pulse−train can be turned on and off; pressing

done returns the display directly to the

screen. The pulse−t r ain is built only after whenever

done is pressed, assuming a change has been made. The f ir st screen, shown

above, sets the number of pulses (1−10) in the patt er n; enter the number of pulses directly from the keyboard or by using the rotary control.

WAVEFORM FUNCTIONS screen from any setup

next is pressed after the last parameter set up or

Pressing

next calls the pulse train period screen:

Pulse train period: 100·00000 us 10000pt*10.000000ns

done next

The period can be set, with 8−digit resolution, from 40·00ns to 100s by direct keyboard entries or by using the rotary control.

Pressing

next calls the baseline voltage screen, the last of the general setup screens:

Enter the baseline voltage: +0·000 V

done next

The baseline is the signal level between the end of one pulse and the start of t he next, i. e. it is the level all pulses start and finish at. The baseline can be set between −5·0V and +5·0V by direct keyboard entries or by using the rotary contr ol. Note that the

actual baseline level at

the output will only be as set in this field if the output amplitude is set t o m aximum (10Vpp into 50Ω) on the AMPLITUDE screen and terminated in 50Ω. If the amplitude was set to 5Vpp int o 50Ω then the actual baseline range would be −2·5V to + 2· 5V for set values of −5·0 to +5·0V, i.e. the amplitude control “scales” the baseline setting. The actual output levels are doubled when the output is unterminated.

Pressing

next on this screen calls the first of 3 s cr eens for the first pulse in the pattern:

Pulse 1 level

+5·000 V

done next

The pulse level can be set on this screen between −5·0V and +5·0V by direct keyboard entr ies or by using the rotary control. As with the baseline level described above the set pulse levels are only output if the amplitude setting is set t o m aximum ( 10Vpp int o 50Ω) on the AMPLITUDE screen and terminated in 50Ω. Adjusting the amplitude “scales” both the peak pulse levels and baseline together, thus keeping the pulse shape in proportion as the amplitude is changed, exactly as for arb waveforms. Actual output levels are doubled when the output is unterminated.

Note that by pressing the Pulse soft−key on this (and subsequent screens) the pulse to be edited can be directly set from the k eyboard or by using t he rotary control; this is useful in directly accessing a particular pulse in a long pulse train instead of having t o s t ep t hrough the whole sequence.

◊ ♦

◊

◊ ♦

◊

♦

Pressing next calls the pulse width screen for the first pulse:

Pulse 1 width

progrm 25·000000 us

actual 25·000000 us

done next

The width can be entered directly from the keyboard or by using the rotary control. Any value in the range 10·00ns to 99·99s can be programmed but the

reason the between

actual pulse width is shown below the program wi dth. The variation

program and actual will only really be noticeable for very short pulse−train

actual value may differ; for this

periods (only a few points in the pulse−train) and very long periods (each of the 50,000 points has a long dwell time) for exactly the same reasons as described in the Pulse Setup sec t ion; refer to that sect ion for a detailed explanation.

Pressing

next calls the pulse delay screen for the first pulse:

Pulse 1 delay

progm +0·0000000 ns

actual +0·0000000 ns

done next

The pulse delay is entered in the same way as pulse width and, again, the actual delay is shown below the

program delay for the same reasons. The delay value that can be entered

must be in the range ± (pulse−t r ain per iod −1 point); positive values delay the pulse with respect to waveform sync from SYNC OUT; negative values cause the pulse to be output before t he waveform sync.

Pressing

next on this screen calls the first of the 3 screens for setting the paramet ers of

Pulse 2, and so on through all the pulses in the pulse−train. I n this way all parameters of all pulses are set. The pulse−train is built when pulse or if

done is pressed on any screen.

next is pressed on the last screen of the last

Care must be taken that the set widths and delays of the individual pulses are compatible with each other and the overall pulse−train period, i.e. delays must not be s uch that pulses overlap each other and delays + widths must not exceed the pulse−train period; unpredictable results will occur if these rules are not followed.

Once the pulse−train has been defined the per iod can be adj usted irrespective of the pulse width and delay settings for the individual pulses because, unlike a conventional pulse generator, the individual pulse widths and delays are adjusted proportionally to the period as the period is changed.

Period can also be changed from the PULSE-TRN PERIOD scr een called by pressing t he FREQ key with pulse−train mode selected:

PULS-TRN PER: 100·00000 us

freq period

The new setting can be entered either as a period in the way already described or as a fr equency by first pressing the slightly different from changing period on the

freq soft−key. However, changing the period/frequency from this scr een is

pulse-train setup screen. W hen changing

from this screen the number of points in the waveform is never changed (just as with a true arb) which means that the shortest period/highest frequency that can be set is the number of waveform points x 10·00ns. To achieve faster f requencies (up to the specification limit) the period must be changed from t he pulse-train set-up screen; changing the frequency from the pulse-train set-up screen causes the number of points t o be r educed as t he per iod is r educed ( for period <1·00ms).

◊

External modulation can be set to VCA (Voltage Cont r olled Amplitude) or SCM (Suppressed Carrier Modulation) modes. Pressing the MODULATION key calls the

The source soft−key steps the modulation choice between off and external. With presses of the

ext selected the modulation can be switched between VCA and SCM with alternate

External VCA

Select VCA with the type soft−key on the MODULATION screen. Connect t he modulating signal to the MODULATION IN socket on the rear panel (nominally 1kΩ input

impedance); a positive voltage increases the output amplitude and a negat ive voltage decreases the amplitude. Note that clipping will occur if the combinat ion of amplitude setting and VCA signal attempts to drive the output above 20Vpp open−circuit voltage.

External AM is achieved by setting the required output level and applying the modulation signal (which can be AC coupled if required) at the appropr iat e level to obtain the modulation dept h required. If the out put level is changed the amplitude of the modulating signal will have to be changed to maintain the same modulation depth.

The VCA signal is applied to the amplifier chain prior to the output attenuators. The amplif ier itself is controlled over a limited range (~10dB) and the full amplitude range is achieved by switching in up to five –10dB attenuation stages. Peak m odulat ion cannot exceed the m aximum of the “range” within which the channel output has been set by choice of am plit ude set ting; it is up to the user to observe the waveforms when using external VCA and to make adjustments if the waveform is clipping. Note that it is not possible to give a simple guide as to where the “range” breakpoints are because the use of DC Offset, for example, changes these points.

Within each “r ange” the maximum output setting at which clipping is avoided is reduced fr om range maximum to half this value as modulation is increased from 0% to 100%; 100% modulation will be achieved at this mid−range setting with an external VCA signal of approximately 1Vpp. Modulation frequency range is DC to 100kHz.

It is also possible to modulate a DC level from the generator with a signal applied to the MODULATION IN socket, as follows. Set the generator to external tr ig ger on the

IN setup screen but do not apply a trigger signal to TRIG IN; select squarewave. The MAIN

OUT is now set at the peak positive voltage defined by the amplitude setting; pressing the ± ke y with

AMPLITUDE displayed will set the level to the peak negative voltage. This DC level can

now be modulated by the signal applied to the MODULAT ION IN input.

Modulation

MODULATION set−up screen.

MODULATION

source: ext

type: VCA

type soft−key. External modulation can be used with external Sum.

TRIGGER

External SCM

Select SCM with the type soft−key on the MODULATION screen. Connect t he modulating signal to the MODULATION IN input on the rear panel (nominally 1kΩ input

impedance). W it h no s ig nal t he carrier is fully suppressed; a positive or negative level change at the modulation input increases the amplitude of t he c ar r ier. Note that clipping will occur if the SCM signal attempts to drive the output above the 20Vpp open−circuit voltage.

Peak modulation, i.e. maximum carrier am plit ude ( 20Vpp) , is achieved with an external SCM level of approximately ±1V, i. e. a 2Vpp signal. Modulation frequency range is DC to 100kHz.

When external SCM is selected the amplitude contr ol is disabled; t he screen shows the message

fixed by SCM.

AMPLITUDE setup

◊

Sum

External summing can be used to add ‘noise’ to a waveform, for example, or to add two signals for DTMF (Dual Tone Multiple Frequency) testing.

In Sum mode an external signal applied to the SUM input on the rear panel is summed with the selected waveform. Pressing the SUM key calls the

SUM set−up screen.

SUM source: ext

CH1 +2·00 Vpp

Pressing the source soft−key steps the Sum sour c es bet ween off and external. With Clipping will occur if the Sum input level attempts to drive the channel amplitude above the

maximum 20Vpp open−circuit voltage. However, the relationship between the SUM input and the maximum summed output depends not only on the Sum input level but also on the generat or amplitude setting. This is because the Sum input is applied to the amplifier chain prior to the output attenuators; the am plifier itself is controlled over a limited range (~10dB) and the full amplitude range is achieved by switching in up to five –10dB attenuation stages. The summed output cannot exceed the maximum of the “r ange” within which the output has been set by choice of amplitude setting; it is up t o the user to observe the waveforms when using external sum and to make adjustments if t he waveform is clipping . Not e t hat it is not possible to give a simple guide as to where the “range” breakpoints are because the use of DC Offset, for example, changes these points.

Within each “r ange” a SUM signal of ~2Vpp will force the channel output from r ange minimum to range maximum; if the amplitude is set to mid−range the SUM signal needed to force t he out put to range maximum is about half, i.e. ~1Vpp.

ext selected the screen is as shown above.

To facilitate the s et ting of appropriate Sum and amplitude levels the output amplitude can also be changed from the with d irec t keyboard entries or by using the rotary knob.

SUM set−up screen. Press the CH1 soft−key and adjust the amplitude

Two generators can be synchronised together following the procedure outlined below. It is possible to link more than two generators in this way but results are not guaranteed.

Synchronising Principles

Frequency locking is achieved by using the clock output from the ‘master ’ generator t o dr ive the clock input of a slave. The additional connection of an initialising SYNC signal permits the slave to be synchronised such that the phase relationship between master and slave outputs is that specified on the slave generator’s TRIGGER/GAT E set−up screen.

Synchronisation is only possible between generators when the ratio of the master and slave frequencies is rational, e.g. 3kHz can be synchronised with 2kHz but not with 7kHz. Special considerations arise with waveforms generated by Clock Synthesis mode (sq uar ewave, arbitrar y, pulse, pulse−train and sequence) because of the relatively poor precision with which the frequency is actually derived in the hardware. With these waveforms, frequenc ies with an apparently rational relationship (e.g. 3:1) may be individually synthesised such that the ratio is not close enough to e.g. 3:1 to m aintain phase lock over a per iod of time; the only relationships guaranteed to be realised precisely are 2 mode are binary. A further c om plication ar ises with arb waveform s becaus e waveform frequency depends on both waveform size and clock frequency (wavefor m frequency = clock freq uency

÷ waveform size). The important relationship with arbs is the ratio of clock frequencies and

the above considerations on precision apply to them. The most practical use of synchronisat ion will be to provide outputs at the same frequency, or maybe harmonics, but with phase differences.

Synchronising Two Generators

:1 because the division stages in Clock Synthesis

Connections for Synchronisation

The clock connection arrangem ent is for the rear panel REF CLOCK IN/OUT of the master (which will be set to

slave (which will be set to

master) to be connected directly to the REF CLOCK IN/OUT socket of the

slave).

Similarly the synchronising connection is from the SYNC OUT of the mas t er, which defaults to

phase lock, to the TRIG IN input of the slave.

Generator Set-ups

Each generator can have its main parameters set to any value, with the exception that t he r atio of frequencies between master and slave must be rational and each generator can be set to any waveform, but see Synchronising Principles section above.

The master has its REF CLOCK IN/OUT set to master on the REF. CLOCK: menu called by the

Repeated presses of the ref clk soft−key toggle between input, output, master

slave.

and

ref. clock soft−key on the UTILIT Y screen, see System O per ations section.

REF. CLOCK:

ref clk: input

The slave is set to

slave. Setting the slave generator to slave forces the slave’s mode

to continuous and defaults the SYNC OUT output to phase lock. The phase relationship bet ween the slave and the master is set on the TRIGGER/GATE set−up screen of the slave, accessed by pressing the

triggered set-up... soft-key on the MODE screen, see the Start Phase

section of the Triggered Burst and Gate chapter.

♦ ◊

The convention adopted for the phase r elat ionship between gener at or s is t hat a pos itive phase setting advances the slave generator with respect to the master and a negative setting delays the slave generator.

Hardware delays become increasingly significant as freq uency increases c ausing additional phase delay between the master and slave. However, these delays can be largely nulled−out by ‘backing−off ’ the phase settings of the slave.

Typically these hardware delays are as follows:

Synchronising

Having made the connections and set up the generator s as desc r ibed in the pr ec eding paragraphs, synchronisation is achieved by pressing the MAN TRIG key of the slave. Once synchronised any change to the setup will require resynchronisation with the MAN TRIG key again.

TRIGGER/GATE SETUP:

burst cnt: 0000001

phase: +000.0°

(actual: +000·0°)

DDS waveforms: <± 25ns; <1° to 100kHz Clock Synthesised waveforms: <300ns; <1° to 10kHz.

Other Phase-Locking Considerations

The following further points should also be considered.

• The waveform filters int r oduce a frequency−dependent delay above ~1MHz; this will affect

the accuracy of the phase between locked waveforms at different frequencies, e.g . 500kHz and 5MHz.

• Square waves, which are 2−point Clock Synthesised waveforms will not reliably lock to other

Clock Synthesised waveforms.

• Pulse and Pulse train waveforms will lock to other Pulse and Pulse−trains ( and eac h ot her )

but should be built with equal periods.

• Arb waveforms should be the same lengt h ( alt hough this is not forced and does not create an

error message).

• To avoid excessive locking tim es when using DDS waveforms t he actual frequency is offset

by a small amount (<1ppm) to ensure that no frequency is an exact sub-multiple of the 100MHz clock frequency. This in turn ensures that the master inst rument will always produce the required locking signal from the SYNC OUT socket. This frequency offset is applied in three ranges: 0 to 25kHz, 25kHz to 1MHz and 1MHz to 40MHz. It is not possible to lock frequencies from different ranges.

◊

◊ ◊

◊

System Operations from the Utility Menu

Pressing the UTILITY key calls a list of menus which g ive access to various system oper ations including storing/recalling set−ups from battery backed memory, error messages, power on settings and calibration.

Each of the following operations are accessed by pressing the appropriate soft-key on the

UTILITY MENU. Press UTILITY again at any time to retur n to the main Utility menu.

Storing and Recalling Set-ups

Complete set-ups can be stored to or recalled f r om non-volatile memory using the screens called by the

Pressing

Nine stores numbered 1 to 9 inclusive are available. Select the store using the rotar y contr ol or direct keyboard entry and press to

Pressing

store and recall soft-keys.

store... calls the screen:

recall... (or the RECALL front panel key) calls the RECALL screen:

Save to store No: 1

execute

execute implement the store function.

The required set-up is selected using t he r otar y contr ol or direc t keyboard entry and the recall is actioned with the

using the

set defaults soft-key. Note that loading the defaults does not change any

execute soft-key. The factory defaults (see Appendix 3) can be recalled

arbitrary waveforms or stored setups or the RS232/G PI B/ USB inter face settings.

Warnings and Error messages

The default setup is for all warning and err or m es sages to be displayed and for a beep to sound with each message. This setup can be changed on the error… menu:

Each feature can be turned ON or O FF with alternate presses of the appropriate soft−key. The last two error messages can be viewed by pressing the last error… soft−key. Each

message has a number and the full list appear s in Appendix 1. See also Warnings and Error Messages in the Standard Waveform Operation section.

Recall store No: 1:

set defaults

execute

error beep: ON error message: ON

warn beep: ON

warn message: ON

Remote Interface Setup

Pressing remote... calls the REMOTE setup screen which permits RS232/GPIB/USB choice and selection of address and Baud rate. Full details are given in the Remote O per ation section.

◊

Reference Clock In/Out Setting

The function of the r ear panel REF CLOCK IN/OUT sock et is set on the REF. CLOCK screen, called by pressing the ref. clock soft−key.

The default setting is for the socket to be set to input, i.e. an input for an external 10MHz reference clock. When set to input the system is autom atically switched over to the external reference when an adequate signal level (TTL/ CMOS threshold) is det ected at REF CLOCK IN/OUT but will continue to run from the internal clock in t he abs ence of such a signal.

With the clock set to output a buffered version of the internal 10MHz clock is made available at the socket.

Select master or slave when used for synchronising (phase−locking) multiple generators. See Synchronising Generat or s s ect ion for full details.

Power On Setting

Pressing the power on… soft−key calls the POWER ON SETTING screen:

REF. CLOCK:

ref clk: input

The setting loaded at power on can be selected with the appropriate s of t−key to be default values (the default setting) , restore last setup ( i. e. the settings at power down are

restored at power up) or any of the stor ed settings. The complete list of set-ups can be scrolled through with further presses of the

default values restores the factor y def ault s et t ings, see Appendix 3.

System Information

The system info… soft−key calls the SYSTEM INFO screen which shows the instrument name and firmware revision. When system info… is pressed a checksum is also made of the firmware code and the result displayed; this can be used when a firm ware fault is suspected, to check that the code has not got corrupted.

Calibration

Pressing calibration calls the calibration routine, see Calibration section.

POWER ON SETTING

default values

restore last setup

recall store 1

recall soft-key, the cursor keys or the rotary control.

◊ ◊

−−−−

All parameters can be calibrated without opening the case, i.e. t he generator offers ‘closed−box’ calibration. All adjustments are made digitally with calibration constants stored in EEPROM. The calibration routine requires only a DVM and a frequency counter and takes no m or e than a few minutes.

The crystal in the timebase is pre−aged but a further ageing of up to ±5ppm can occur in the first year. Since the ageing rate decreases exponentially with time it is an advantage to recalibrate after the first 6 m ont h’s use. Apart from this it is unlikely that any other parameters will need adjustment.

Calibration should be carried out only after the generator has been oper ating for at least 30 minutes in normal ambient conditions.

Equipment Require d

• 3½ digit DVM with 0·25% DC accuracy and 0·5% AC accuracy at 1kHz.

• Frequency counter capable of measuring 10·00000MHz.

The DVM is connected to the MAIN OUT and the counter to the SYNC OUT. Frequency meter accuracy will determine the accuracy of the generator’s clock setting and

should ideally be ±1ppm.

Calibration

Calibration Procedure

The calibration procedure is accessed by pressing the calibration… soft−key on the UTILITY screen.

The software provides for a 4−digit password in the rang e 0000 to 9999 to be used to access the calibration procedure. If the password is left at the factory default of 0000 no mess ages are shown and calibration can proceed as described in the Calibration Routine section; only if a non−zero password has been set will the user be prompted to enter the password.

Setting the Password

On opening the Calibration screen press the password… soft−key to show the password screen:

Enter a 4−digit password from the k eyboard; t he display will show the message NEW PASSWORD STORED! for two seconds and then revert to the UTILITY m enu. If any keys other than 0−9 are pressed while entering the password the messag e ILLEGAL PASSWORD! will be shown.

CALIBRATION SELECTED Are you sure ?

password… tests…◊ exit continue◊

ENTER NEW PASSWORD

Using the Password to Access Calibration or Change the Password

With the password set, pr es sing calibration… on the UTILITY screen will now show:

ENTER PASSWORD

----

CAL 03

CH1. DC offset zero.

Adjust for 0V ± 5mV

CAL 04

CH1. DC offset at + full scale.

Adjust for + 10V ± 10mV

CAL 05

CH1. DC offset at − full scale.

Check for –10V ± 3%

CAL 06

CH1. Multiplier zero.

Adjust for minimum Volts AC

CAL 07

CH1. Multiplier offset.

Adjust for 0V ± 5mV

CAL 08

CH1. Waveform offset.

Adjust for 0V ± 5mV

CAL 09

CH1. Output level at full−scale

Adjust for 10V ± 10mV

CAL 10

CH1. 20dB attenuator

Adjust for 1V ± 1mV

CAL 11

CH1. 40dB attenuator

Adjust for 0·1V ± ·1m V

CAL 12

CH1. 10dB attenuator

Adjust for 2·236V AC ± 10mV

CAL 13

CH1. Not used.

CAL 14

CH1. Not used.

CAL 15

CH1. Not used.

CAL 16

Level 0.1 MHz

Note reading

CAL 17

Level 33MHz

Check reading

CAL 18

Level 1MHz

Adjust for same reading

CAL 19

Level 2MHz

Adjust for same reading

CAL 20

Level 4MHz

Adjust for same reading

CAL 21

Level 5MHz

Adjust for same reading

CAL 22

Level 10MHz

Adjust for same reading

CAL 23

Level 15MHz

Adjust for same reading

When the cor r ect password has been entered from the keyboard the display changes to the opening screen of the calibration rout ine and calibrat ion can pr oceed as described in the Calibration Routine section. If an incorrect password is entered t he message INCORRECT PASSWORD! is shown for two seconds before the display reverts to the UTILITY menu.

With the opening screen of the calibration routine displayed after correc t ly entering the password, the password can be changed by pressing password... soft−key and following the proc edur e described in Setting the Password. If t he password is set to 0000 again, password protection is removed.

The password is held in EEPROM and will not be lost when the memory battery back−up is lost. In the event of the password being forg ot ten, contact the manufacturer for help in resetting the instrument.

Calibration Routine

The calibration procedure proper is entered by pressing continue on the opening Calibration screen; pressing exit returns t he display to the UTILITY menu. Pressing tests… calls a menu of basic hardware checks used at product ion t est; these are largely self−explanatory but details can be found in the Service Manual if required. At each step the display changes to prompt the user to adjust the rotary control or cursor keys, until the reading on the specified instrument is at the value given. The cursor keys provide coarse adjustment, and the rotary control fine adjustment . Pr ess ing next incr ements the procedure to the next step; pressing CE decrements back to the previous step. Alternatively, pressing exit returns the display to the last CAL screen at which the user can choose to either save new values, recall old values or calibrate again.

The first two displays (CAL 00 and CAL 01) specify the connections and adjustment method. The next display (CAL 02) allows the starting channel to be chosen; this allows quick access to any particular channel. To calibrate the complete inst r um ent c hoose the default setting of CH1. The subsequent displays, CAL 03 to CAL 31, permit all adjustable parameters to be calibrated.

The full procedure is as follows:

CAL 24

Level 20MHz

Adjust for same reading

CAL 25

Level 25MHz

Adjust for same reading

CAL 26

Level 30MHz

Adjust for same reading

CAL 27

Level 32·5MHz

Adjust for same reading

CAL 28

Level 35MHz

Adjust for same reading

CAL 29

Level 37·5MHz

Adjust for same reading

CAL 30

Level 40MHz

Adjust for same reading

CAL 31

Clock calibrate

Adjust for 10·00000 MHz at SYNC OUT.

sub−commands:−

other calibration commands will be recognised.

SAVE

Finish calibration, save the new values and exit calibration mode.

commands.

issued for the new value to be accepted.

CALSTEP

Step to the next calibration point.

Remote Calibration

Calibration of the instrument may be performed over the RS232 or GPIB interfac e. To completely automate the process the multimeter and frequency meter will also need to be remote controlled and the controller will need to run a calibration program unique t o t his inst r ument.

The remote calibration commands allow a simplified version of m anual calibrat ion t o be performed by issuing commands from the controller. The controller must send the CALADJ command repeatedly and read the dmm or f r equency meter until the required result f or the selected calibration step is achieved. The CALSTEP command is then issued to accept the new value and move to the next step.

While in remote calibration mode very little error checking is perform ed and it is t he controllers responsibility to ensure that everything progresses in an orderly way. Only the following commands should be used during calibration.

WARNING: Using any other commands while in calibration mode may give unpredictable results and could cause the instrument to lock up, r equiring the power to be cycled to regain control.

CALIBRATION <cpd> [,nrf]

START Enter calibration mode; this command must be iss ued before any

ABORT Finish calibration, do not save the new values and exit calibration

CALADJ <nrf> Adj ust the selected calibration value by <nrf>. The value must be in

The calibration control command. <cpd> can be one of three

mode. <nrf> represents the calibrat ion password. The password is only

required with CALIBRATION START and then only if a non−zero password has been set from the instrument’s keyboard. The password will be ignored, and will give no errors, at all other times.

It is not possible to set or change the password using r em ot e

the range −100 to +100. Once an adjustment has been completed and the new value is as required the CALSTEP command must be

For general information on rem ot e oper ation and remote command formats, r efer to the following sections.

◊ ◊

The instrument can be remotely controlled via its RS232, USB or GPIB interfaces. When using RS232 it can either be the only instrument connected to the cont roller or it can be part of an addressable RS232 system which permits up to 32 instruments to be addressed fr om one RS232 port.

Some of the following sections are general and apply to all 4 modes (single instrument RS232, addressable RS232, USB and GPIB); others are clearly only relevant to a particular interf ac e or mode. It is only necessary to read the general sect ions plus t hose s pecific to the intended remote control mode.

Remote command format and the remote commands themselves are detailed in the Remote Commands chapter.

Address and Baud Rate Selection

For successful operation, each instr um ent c onnect ed to the GPIB, USB or addressable RS232 system must be assigned a unique address and, in t he cas e of addressable RS232, all must be set to the same Baud rate.

The instrument’s remote address for operation on both the RS232 and GPIB interfaces is set via the remote

screen on the UTILITY menu:

Remote Operation

With interface s elect ed with the interface soft−key, the selection can be stepped between RS232, USB and GPIB with successive presses of the soft−key, the cursor keys or by

using the rotary control. With address

selected, the soft−key, cursor keys or rotary control can be used to set the

address; the address setting is ig nored in USB mode. With baud rate selected, the soft−key, cursor keys or rotary control can be used to set the

baud rate for the RS232 interf ac e. When operating on the GPIB all device operations are performed through a single primary

address; no secondary addressing is used. NOTE: GPIB address 31 is not allowed by the IEEE 488 standards but it is possible to select it as

an RS232 address.

Remote/Local Operation

At power−on the instrument will be in the local state with the REMOTE lamp off. In this state all keyboard operations are possible. When the instrument is addressed to listen and a com m and is received the remote state will be entered and the REMOTE lamp will be turned on. In this state the keyboard is locked out and remote com m ands only will be processed. The instrument may be returned to the local state by pressing the LOCAL key; however, the effect of this action will remain only until the instrument is addressed again or receives another char ac t er from the interface, when the remote state will once again be entered.

REMOTE:

interface: RS232 address: 05 baud rate: 9600

1 − No internal connection

TXD

Transmitted data from instrument

RXD

Received data to instrument

TXD2

Secondary transmitted data (addressable RS232 only)

GND

Signal ground (addressable RS232 only)

Start Bits: 1

Parity: None

Data Bits: 8

Stop Bits: 1

RS232 Interface

RS232 Interface Connector

The 9−way D−type serial inter face connector is located on the instrument r ear panel. The pin connections are as shown below:

Pin Name Description

4 − No internal connection 5 GND Signal ground 6 − No internal connection 7 RXD2 Secondary received data (addressable RS232 only)

Single Instrument RS232 Connecti ons

For single instrument remote control only pins 2, 3 and 5 are connected to the PC. However, for correct operation links must be m ade in t he connec t or at the PC end between pins 1, 4 and 6 and between pins 7 and 8, see diagram. Pins 7 and 8 of the instr um ent m us t not be connected to the PC, i.e. do not use a fully wired 9–way cable.

Baud Rate is set as described above in Address and Baud Rate Selection; the other parameters are fixed as follows:

Addressable RS232 Connections

For addressable RS232 operation pins 7, 8 and 9 of the instrument connector are also used. Using a simple cable assembly, a 'daisy chain' connection system between any number of instruments, up to the maximum of 32 c an be m ade, as shown below:

Start Bits: 1

Parity: None

Data Bits: 8

Stop Bits: 1

The daisy chain consists of the transmit data (T XD), receive date (RXD) and signal ground lines only. There are no control/handshake lines. This makes XON/XOFF protocol essential and allows the inter−connection between instruments to contain just 3 wires. The wiring of the adaptor cable is shown below:

All instruments on the interface must be s et t o the same baud rate and all must be powered on, otherwise instruments further down the daisy chain will not receive any data or commands.

The other parameters are f ixed as f ollows:

RS232 Character Set

Because of the need for XO N/ XOFF handshake it is possible to send ASCII coded data only; binary blocks are not allowed. Bit 7 of ASCII codes is ignored, i.e. assumed to be low. No distinction is made between upper and lower case characters in command mnem onics and t hey may be freely mixed. The ASCII codes below 20H (space) are reserved for addressable RS232 interface control. In t his m anual 20H, et c . m eans 20 in hexadecimal

Addressable RS232 Interface Control Codes

All instruments intended for use on the addressable RS232 bus use the following set of interface control codes. Codes between 00H and 1FH which are not listed here as having a particular meaning are reserved for f uture use and will be ignored. Mixing interface control codes inside instrument commands is not allowed except as stated below for CR and LF codes and XON and XOFF codes.

When an instrum ent is first powered on it will automatically enter the Non− Addressable mode. In this mode the instrument is not addressable and will not respond to any address com m ands. This allows the instrument to function as a normal RS232 contr ollable device. This mode may be locked by sending the Lock Non−Addressable mode cont r ol code, 04H. The controller and instrument can now freely use all 8 bit codes and binary blocks but all interface control codes are ignored. To return t o addressable mode the instrument must be powered off.

To enable addressable mode aft er an instrument has been powered on the Set Addressable Mode control code, 02H, must be sent. This will then enable all instruments connected to the addressable RS232 bus to respond to all interface contr ol codes. To return to Non−Addressable mode the Lock Non−Addressable mode control code m ust be sent which will disable addressable mode until the instruments are powered off.

12H

Listen Address for any instrument.

14H

Talk Address followed by an address not belonging to this instrument .

03H

Universal Unaddress control code.

04H

Lock Non−Addressable mode control code.

18H

Universal Device Clear.

02H

Set Addressable Mode.

03H

Universal Unaddress control code.

04H

Lock Non−Addressable mode control code.

06H

Acknowledge that listen address received.

0AH

Line Feed (LF); used as the universal command and response term inat or.

0DH

Carriage Return (CR); for m atting code, otherwise ignored.

11H

Restart transmission (XON).

12H

Listen Address − must be followed by an address belonging to the req uir ed inst r ument.

Before an instrument is sent a com m and it m ust be addressed to listen by sending the Listen Address control code, 12H, followed by a single character which has the lower 5 bits corresponding to the unique address of the required instrument, e. g. the codes A−Z or a−z give the addresses 1−26 inclusive while @ is address 0 and so on. Once addressed to listen the instrument will read and act upon any commands sent until the listen mode is cancelled.

Because of the asynchronous nature of the interface it is necessary for the cont r oller to be informed that an instrument has acc ept ed t he list en addr es s sequence and is ready to receive commands. The controller will therefore wait for Acknowledge code, 06H, before sending any commands, The addressed instrument will provide this Acknowledge. The controller should time−out and try again if no Acknowledge is received within 5 seconds.

Listen mode will be cancelled by any of the following interface control codes being rec eived:

12H Listen Address followed by an address not belonging to this instrument. 14H Talk Address for any instrument. 03H Universal Unaddress control code. 04H Lock Non−Addressable mode control code. 18H Universal Device Clear.

Before a response can be read fr om an instrument it must be addressed to talk by sending t he Talk Address control code, 14H, followed by a single character which has the lower 5 bits corresponding to the unique address of the required instrument, as for the listen address control code above. Once addressed to talk the instrument will send the response mes sage it has available, if any, and t hen exit t he talk addr es sed stat e. Only one response message will be sent each time the instrument is addressed to talk .

Talk mode will be cancelled by any of the following interface control codes being received:

Talk mode will also be cancelled when the instrument has complet ed sending a response message or has nothing to say.

The interface code 0AH (LF) is the universal comm and and r espons e t er minator; it must be the last code sent in all commands and will be the last code sent in all responses.

The interface code 0DH (CR) may be used as requir ed t o aid t he formatting of comm ands ; it will be ignored by all instruments. Most instruments will terminate responses with CR followed by LF.

The interface code 13H (XO FF) m ay be sent at any tim e by a listener ( inst r um ent or controller) to suspend the output of a talker. The listener must send 11H (XON) before the talker will resume sending. This is the only form of handshake control supported by the addressable RS232 mode.

Full List of Addressable RS232 Interface Control Codes

13H

Stop transmission (XOFF).

14H

T alk Address − must be followed by an address belonging to the required instrument.

18H

Universal Device Clear.

Source Handshake

SH1

Acceptor Handshake

AH1

Talker

Listener

Service Request

SR1

Remote Local

RL1

Parallel Poll

PP1

Device Clear

DC1

Device Trigger

DT1

Controller

Electrical Interface

USB Interface

The USB interface allows the instrument to be cont r olled via a PC’s USB port. The instrument is supplied with a CD containing drivers for various versions of Windows, including Win98 and

2000. Any driver updates are available via the TTi website, www.tti-test.com. The CD also contains a .pdf file with information and details of t he software installation procedure.

Installation of the driver is achieved by connecting the instrument t o a PC via a standard USB cable. The Windows’ plug and play functions should automatically recognise the addition of new hardware attached to the USB interface and if t his is t he first time the connection has been made, prompt for t he locat ion of a suitable driver. Provided that the standard Windows prompts are followed correctly Windows will install the appropriate driver. The driver will remain installed on the PC and should be called automatically each time the instrument is connected t o t he PC via USB in the future.

The waveform design software supplied with this generator has been enhanc ed t o per m it downloads to the instrument using USB. For users wishing to write their own application software for USB communication with the generat or, the relevant information is supplied on the CD containing the drivers themselves.

GPIB Interface

The 24−way GPIB connector is located on the instrument r ear panel. The pin connections are as specified in IEEE Std. 488.1−1987 and the instrument complies with IEEE Std. 488.1−1987 and IEEE Std. 488.2−1987.

GPIB Subsets

This instrument contains the following IEEE 488.1 subsets:

GPIB IEEE Std. 488.2 Error Handling

The IEEE 488.2 UNTERMINATED error (addressed to talk with nothing t o s ay) is handled as follows. If the inst rument is addressed to talk and the response formatter is inactive and the input queue is empty then the be set in the Standard Event Stat us Register, a value of 3 to be placed in the Query Error Register and the parser to be reset. See t he Status Reporting section f or further information.

UNTERMINATED error is generated. This will cause the Query Error bit to

bit 7 =

don't care

bit 4 =

0 bit 3 =

Sense

sense of the response bit; 0 = low, 1 = high

bit 2 =

The IEEE 488.2 INTERRUPTED error is handled as follows. If t he response formatter is waiting to send a response message and a or the input queue contains more than one END messag e then the instrument has been

INTERRUPTED and an error is generated. This will cause the Query Error bit to be set in t he

Standard Event Status Reg ist er, a value of 1 to be placed in the Query Error Reg ist er and the response formatter to be reset thus clearing the output queue. The parser will then start parsing the next

<PROGRAM MESSAGE UNIT> from the input queue. See the Status Reporting section for

further inform at ion. The IEEE 488.2

send a response message and the input q ueue becomes full then the instrument enter s t he

DEADLOCK state and an error is generated. This will cause the Query Error bit to be set in the

Standard Event Status Regist er, a value of 2 to be placed in the Query Error Reg ist er and t he response formatter to be reset thus clearing the output queue. The parser will then start parsing the next

<PROGRAM MESSAGE UNIT> from the input queue. See the Status Reporting section for

further inform at ion.

GPIB Parallel Poll

Complete parallel poll capabilities are offered on this generator. The Parallel Poll Enable Register is set to specify which bits in the Status Byte Register are to be used to form the message The Parallel Poll Enable Register is set by the *PRE <nrf> comm and and r ead by the *PRE? command. The value in the Parallel Poll Enable Register is ANDed with the Status Byte Register; if t he result is zero then the value of

<PROGRAM MESSAGE TERMINATOR> has been read by the parser

DEADLOCK error is handled as follows. If the response formatter is waiting to

ist local

ist is 0 otherwise the value of ist is 1.

The instrument must also be configured so that the value of

ist can be returned to the controller

during a parallel poll operation. The instrument is configured by the cont r oller sending a Parallel Poll Configure command (PPC) followed by a Parallel Poll Enable command (PPE). The bits in the PPE command are shown below:

bit 6 = 1 bit 5 = 1 Parallel poll enable

bit 1 = ? bit position of the response bit 0 = ?

Example. To return the RQS bit (bit 6 of the Status Byte Register) as a 1 when true and a 0 when

false in bit position 1 in response to a parallel poll operation send the following commands

*PRE 64

<pmt>, then PPC followed by 69H (PPE)

The parallel poll response from the generat or will then be 00H if RQS is 0 and 01H if RQ S is 1.

During parallel poll response the DIO interface lines are resist ively term inat ed ( passive termination). This allows multiple devices to share the same response bit position in either wired−AND or wired−OR configuration, see IEEE 488.1 for more information.

Status Reporting

This section describes the complete status model of the instrument. Note that som e registers are specific to the GPIB section of the instrument and are of limited use in an RS232 environment.

Bit 7 −

Power On. Set when power is first applied to the instrument.

Bit 6 −

Not used.

bus. The parser is reset and parsing continues at the next byte in the input stream.

Execution Error Register.

Bit 3 −

Not used.

reported in the Query Error Register as list ed below.

1. Interrupted error

2. Deadlock error

3. Unterminated error

Bit 1 −

Not used.

Bit 0 −

Operation Complete. Set in response to the * O PC com m and.

Bit 7 −

Not used.

response to a Serial Poll and MSS I−s returned in response to the *STB? com m and.

the Response Message Terminator has been sent.

Bit 3 −

Not used.

Bit 2 −

Not used.

Bit 1 −

Not used.

Bit 0 −

Not used.

St andard Ev ent Status and St and ard Ev en t S tatus Enable Registers

These two registers are implemented as r equired by the IEEE std. 488.2. Any bits set in the Standard Event Status Register which correspond to bits set in the Standard Event Status Enable Register will cause the ESB bit to be set in the Status Byte Register.

The Standard Event Status Reg ist er is read and cleared by the *ESR? command. The Standard Event Status Enable register is set by the *ESE <nrf> command and read by the *ESE? command.

Bit 5 −

Bit 4 −

Bit 2 −

Command Error. Set when a syntax type error is detected in a command from the

Execution Error. Set when an error is encountered while attempting to execute a completely parsed command. The appropriate error number will be reported in the

Query Error. Set when a query error occurs. The appropriate error number will be

Status Byte Register and Service Request Enable Register

These two registers are implemented as r equired by the IEEE std. 488.2. Any bits set in the Status Byte Register which correspond to bits set in the Service Request Enable Register will cause the RQS/MSS bit to be set in the Status Byte Register, thus generating a Service Request on the bus.

The Status Byte Register is read either by the *STB? command, which will return MSS in bit 6, or by a Serial Poll which will return RQS in bit 6. The Service Request Enable register is set by the *SRE <nrf> command and read by the *SRE? command.

Bit 6 −

Bit 5 −

Bit 4 −

RQS/MSS. This bit, as defined by IEEE Std. 488.2, contains both the Requesting Service message and the Master Status Summary message. RQS is returned in

ESB. The Event Status Bit. This bit is set if any bits set in the Standard Event Status

MAV. The Message Available Bit. This will be set when the instrument has a response message formatt ed and r eady to send t o the controller. The bit will be cleared after

Status Byte Register

= 0

Service Request Enable Register =

= 0

Standard Event Status Regist er

= 128 (pon bit set)

Standard Event Status Enable Register =

= 0

Execution Error Register

= 0

Query Error Register

= 0

Parallel Poll Enable Register =

= 0

Power on Se ttings

The following instrument status values are set at power on:

= Registers marked thus ar e spec ific to the GPIB section of the instr um ent and ar e of limited use in an RS232 environment.

Status Model

The instrument will be in local state with the keyboard active. The instrument parameters at power on are det er mined on the POWER ON SETTING screen

accessed from the UTILITY menu. If restore last setup or recall store no. nn has been set and a defined state is required by the contr oller at s tart up then the command ∗RST

should be used to load the system defaults. If for any reason an err or is det ec t ed at power up in the non−volatile ram a warning will be issued

and all settings will be returned to their default states as for a *RST command.

RS232 Remote Com m and Formats

Serial input to the instrument is buffer ed in a 256 byte input queue which is filled, under interrupt, in a manner transparent to all other instrument operations. The instrument will send XOFF when approximately 200 characters are in the queue. XO N will be sent when approximately 100 free spaces become available in the queue after XOFF was sent. This queue contains raw (un−parsed) data which is taken, by the parser, as required. Commands (and queries) are executed in order and the parser will not start a new command until any previous command or query is complete. In non–addressable RS232 mode responses to c om m ands or queries are sent immediately; there is no output queue. I n addr es sable m ode t he r es ponse formatter will wait indefinitely if necessary, until the instrument is addressed to talk and the complete response message has been sent, befor e t he parser is allowed to start t he next com m and in t he input queue.

Commands must be sent as specified in the com m ands list and m us t be terminated with the command terminator code 0AH (Line Feed, LF). Com m ands m ay be sent in groups with individual commands separated from each other by the code 3BH (;). The gr oup must be terminated with command terminator 0AH (Line Feed, LF) .

Responses from the instrument to the controller are sent as specified in the comm ands list . Each response is terminated by 0DH (Carriage Return, CR) followed by 0AH (Line Feed, LF).

Remote Commands

<WHITE SPACE> is defined as character codes 00H to 20H inclusive with the exception of those

which are specified as addressable RS232 control codes.

<WHITE SPACE> is ignored except in command identif ier s. e.g. '*C LS' is not equivalent to '*CLS'.

The high bit of all characters is ignored. The commands are case insensitive.

GPIB Remote Command Formats

GPIB input to the instrument is buff er ed in a 256 byte input queue which is filled, under interrupt, in a manner transparent to all other instrument operations. The queue contains raw (un−parsed) data which is taken, by the parser, as required. Commands (and queries) are executed in order and the parser will not start a new command until any previous command or query is complete. There is no output queue which means that the res ponse formatter will wait, indefinitely if necessary, until the instrument is addressed to talk and t he com plet e r es ponse m es sage has been sent, before the parser is allowed to start the next com m and in t he input queue.

Commands are sent as or more

<PROGRAM MESSAGE UNIT> elements separated by <PROGRAM MESSAGE UNIT SEPARATOR>

elements. A

<PROGRAM MESSAGE UNIT> is any of the commands in the remote commands list.

<PROGRAM MESSAGE UNIT SEPARATOR> is the semi−colon character ';' ( 3BH).

<PROGRAM MESSAGES> are separated by <PROGRAM MESSAGE TERMINATOR> elements which may

be any of the following: NL The new line character (0AH) NL^END The new line character with the END message ^END The END message with the last character of the message Responses from the instrument to the controller are sent as

<RESPONSE MESSAGE> consists of one <RESPONSE MESSAGE UNIT> followed by a <RESPONSE MESSAGE TERMINATOR>

<RESPONSE MESSAGE TERMINATOR> is the new line character with the END message NL^END.

A Each query produces a specific

the remote commands list.

<PROGRAM MESSAGES> by the controller, eac h m ess age consisting of zero

<RESPONSE MESSAGE> which is listed along with the command in

<RESPONSE MESSAGES>. A

<rmt>

<cpd>

<CHARACTER PROGRAM DATA>, i.e. a short mnemonic or string suc h as O N or O FF.

with the use then rounded up to obtain the value of the command.

<nr1>

A number with no fractional part, i.e. an int eger.

enclosed then all or none of the items are required.

WAVFREQ <nrf>

Set the waveform frequency to <nr f> Hz.

WAVPER <nrf>

Set the waveform period to <nrf> sec.

CLKFREQ <nrf>

Set the arbitrary sample clock f r eq to <nrf> Hz.

CLKPER <nrf>

Set the arbitrary sample clock period to <nr f> sec.

command.

AMPUNIT <cpd>

Set the amplitude units to <VPP>, <VRMS> or <DBM>.

and dc offset entries, to < 50> ( 50Ω), <600> (600Ω) or <OPEN>.

DCOFFS <nrf>

Set the dc offset to <nrf> Volts.

<ARB2>, <ARB3> or <ARB4> .

PULSPER <nrf>

Set the pulse period to <nrf> sec.

PULSWI D <nrf>

Set the pulse width to <nrf> sec.

PULSDLY <nrf>

Set the pulse delay to <nrf> sec.

PULTRNLEN <nrf>

Set the number of pulses in the pulse−t r ain t o < nr f>.

<WHITE SPACE> is ignored except in command identifiers. e.g. '*C LS' is not equivalent to '*CLS'. <WHITE SPACE> is defined as character codes 00H to 20H inclusive with the exception of the NL

character (0AH). The high bit of all characters is ig nor ed. The commands are case insensitive.

Command List

This section lists all commands and queries implemented in this instrument. The commands are listed in alphabetical order within the function groups.

Note that there are no dependent parameters, coupled parameters, overlapping commands, expression program data elements or compound command program headers; each command is completely executed before the next command is started. All commands are sequential and the operation complete message is generated immediately after execution in all cases.

The following nomenclature is used:

<nrf>

[…] Any item(s ) enclosed in t hese br ac kets are optional parameters. If more than one item is

The commands which begin with a * are those specified by IEEE Std. 488.2 as Common commands. All will function when used on the RS232 interface but some ar e of little use.

A number in any format. e.g. 12, 12.00, 1.2 e 1 and 120 e−1 are all accepted as the number 12. Any number, when received, is converted to t he required precision consistent

Frequency and Period

These commands set the f r equency/period of the generator main output and are equivalent to pressing the FREQ key and editing that sc r een.

Amplitude and DC Offset

AMPL <nrf> Set the amplitude to <nrf> in t he units as specified by the AMPUNIT

ZLOAD <cpd> Set the output load, which the generator is to ass um e for amplitude

Waveform Selection

WAVE <cpd> Select the output waveform as <SINE>, <SQ UARE>, < TRIANG>,

<DC>, <POSRMP>, <NEGRMP>, <COSINE>, <HAVSIN>, <HAVCOS>, <SINC>, <PULSE> , <PULSTRN>, <NOISE> , <ARB1>,

PULTRNPER <nrf>

Set the pulse−train period to <nrf > s ec.

PULTRNBASE <nrf>

Set the pulse−train base line to <nrf> Volts.

PULTRNLEV <nrf1>,<nrf2>

Set the level of pulse−train pulse number <nrf1> to <nrf2> Volts.

PULTRNWID <nrf1>,<n rf2>

Set the width of pulse−train pulse number <nrf1> to <nrf2> sec.

PULTRNDLY <nrf1>,<nrf2>

Set the delay of pulse−train pulse number <nrf1> to <nrf2> sec.

command.

and the data ends with <pmt>.

interface.

values as specified for the ARBDEFCSV command.

block this command cannot be used over the RS232 interface.

ARBLEN? <cpd>

Returns the length, in points, of t he ar bit r ary waveform <cpd>.

MODE <cpd>

Set the mode to <CONT>, <GATE>, <TRIG>, <SWEEP> or <TONE>.

BSTCNT <nrf>

Set the burst count to <nrf>.

difference when synchronising instruments.

TONEEND <nrf>

Delete tone frequency number <nrf> thus defining the end of t he list .

gives Gate type.

SWPSTARTFRQ <nrf>

Set the sweep start frequency to <nrf> Hz.

SWPSTOPFRQ <nrf>

Set the sweep stop frequency to <nrf> Hz.

SWPCENTFRQ <nrf>

Set the sweep centre frequency to <nrf> Hz.

SWPSPAN <nrf>

Set the sweep frequency span to <nrf> Hz.

PULTRNMAKE

Makes the pulse−train and runs it − simila r to the WAVE PULSTRN

Arbitrary Waveform Define

ARBDEFCSV <cpd>,<nrf>,< c sv ascii data>

ARBDEF <cpd>,<nrf>,< bin data block >

Define an arbitrary waveform with name <cpd> and length <nr f> and load with the data in <csv ascii data>. The name must be one of ARB1, ARB2, ARB3 or ARB4. The data will overwrite that currently stored for the specif ied ar bit r ary waveform and the waveform will be given the new length. The values are separated by a comma character

Define an arbitrary waveform with name <cpd> and length <nr f> and load with the data in <bin data block>. The name must be one of ARB1, ARB2, ARB3 or ARB4. The data will overwrite that currently stored for the specified arbitrary waveform and the waveform will be given the new length. The data consists of two bytes per point with no characters between bytes or points. The point data is sent high byte first. The data block has a header which consists of the # character followed by several ascii coded numeric characters. The first if these defines the number of ascii characters to follow and these following characters define the lengt h of the binary data in bytes. Due to the binary data block this command cannot be used over the RS232

Arbitrary Waveform Interrogation

ARBDATACSV? <cpd> Returns the data from an existing arbitrary waveform. <cpd> must be

one of ARB1, ARB2, ARB3 or ARB4. The data consists of ascii coded

ARBDATA? <cpd> Returns the data from an existing arbitr ary waveform. <cpd> must be

one of ARB1, ARB2, ARB3 or ARB4. The data consists of binary coded values as specified for the ARBDEF command. Due to the binary data

Mode Commands

PHASE <nrf> Set the generator phase to <nrf> degrees. This parameter is used for

setting the trigg er /gate mode start/stop phase and the phase

TONEFREQ <nrf1>,<nrf2>,<nrf3>

Set tone frequency number <nr f1> to <nrf2> Hz. The third parameter sets the tone type; 1 will give Trig, 2 will give FSK, any other value

SWPT IME <nrf>

Set the sweep time to <nrf> sec.

SWPT YPE < c pd >

Set the sweep type to <CONT>, <TRIG> or <THLDRST> .

SWPDI RN < c p d >

Set the sweep direction to <UP>, <DOWN>, <UPDN> or <DNUP>.

SWPSYNC <cpd >

Set the sweep sync <ON> or <OFF>.

SWPSPACING <cpd>

Set the sweep spacing to <LIN> or <LOG>.

SWPMKR <nrf>

Set the sweep marker to <nrf > Hz.

OUTPUT <cpd>

Set the main output <ON>, <OFF> , <NORMAL> or <INVERT>.

<SWPSYNC> or <PHASLOC>.

<POS> or <NEG>.

TRIGLEV <nrf>

Set the trigger thr eshold level to <nrf> Volts.

TRIGPER <nrf>

Set the internal trigger generator period to <nrf> sec.

source except MANUAL specified.

MOD <cpd>

Set the modulation source to <OFF> or <EXT>.

MODTYPE <cpd>

Set the modulation type to <AM> or <SCM>.

SUM <cpd>

Set the sum source to <OFF> or < EXT>.

REFCLK <cpd>

Set the ref. clock bnc t o < IN>, <OUT>, <MASTER> or <SLAVE>.

ABORT

Aborts an external phase synchronising operation.

difference when synchronising instruments.

∗

Status Byte Register.

∗ESE <nrf>

∗

<nr1> numeric format . The syntax of the respons e is < nr 1> < r m t>.

∗

response is <nr1><rmt>.

∗

<VERSION> is the revision level of the software installed.

∗

1<rmt>, if the local mes sage is true.

Input/Output control

SYNCOUT <cpd> Set the sync output <ON>, <OFF>, <AUTO>, <WFMSYNC>,

<POSNMKR>, <BSTDONE>, < SEQSYNC>, <TRIGGER>,

TRIGIN <cpd> Set the trig input to <INT>, <EXT>, <MAN>, <PREV>, <NEXT>,

FORCETRG Force a trigger to the selected channel. Will function with any trigger

Modulation Commands

Synchronising Commands

PHASE <nrf> Set the generator phase to <nr f> degrees. This parameter is used

for setting the t r ig ger/gate mode start/stop phas e and t he phase

Status Commands

CLS

ESE?

ESR?

Clear status. Clears the Standard Event Status Register, Query Error

Set the Standard Event Status Enable Register to the value of <nrf>.

Returns the value in the Standard Event Status Enable Register in

Returns the value in the Standard Event Status Reg ister in <nr1>

numeric format. The register is then cleared. The syntax of the

IDN?

IST?

Returns the instrument identif icat ion. The exact response is

determined by the instrument configuration and is of the form

<NAME>, <model>, 0, <version><rmt>where <NAME> is the

manufacturer’s name, <MODEL> defines the type of instrument and

Returns ist local message as defined by IEEE Std. 488.2. The

syntax of the response if 0<rmt>, if the local message false or

∗

because of the sequential nature of all operations.

∗

executed because of the sequential nature of all operations.

∗PRE <nrf>

∗

numeric format. The syntax of the response is < nr 1> < r m t>.

∗SRE <nrf>

∗

numeric format. The Syntax of the response is <nr 1> < r m t>.

∗

format. The syntax of the response is <nr1> < r m t>.

∗

action.

∗

0<rmt>.

format is nr1<rmt>.

nr1<rmt>.

∗

instrument are not affected by execution of the ∗LRN? command.

Install data for a previous ∗LRN? command.

∗

DEFAULT INSTRUMENT SETTING S).

∗

number must be in the range 1 to 9.

∗

<nrf>. The store number m ust be in t he r ange 1 to 9.

∗

as *TRG.

FILTER <cpd>

Set the output filter to < AUTO>, < ELI P> , < BESS> or < NO NE>.

BEEPMODE <cpd>

Set beep mode to <ON>, <OFF>, < WARN>, or <ERROR>.

BEEP

Sound one beep.

Will not f unction if LLO is in force.

USBID?

Returns the instruments address.

OPC

OPC?

PRE?

SRE?

STB?

WAI

TST?

EER? Query and clear execution error number register. The response

Sets the Operation Complete bit (bit 0) in the Standard Event Status Register. This will happen immediately the command is executed

Query operation complete status. The syntax of the response is 1<rmt>. The response will be available immediately the command is

Set the Parallel Poll Enable Register to the value <nrf>. Returns the value in the Parallel Poll Enable Register in <nr1>

Set the Service Request Enable Register to <nrf>. Returns the value of the Service Request Enable Register in <nr 1>

Returns the value of the Status Byte Register in <nr1> numeric

Wait for operation complet e t rue. As all commands are completely executed before the next is started this command takes no additional

The generator has no self −test capability and the response is always

QER? Query and clear query error number reg ist er. The response format is

Miscellaneous Commands

LRN?

LRN <character data>

RST

RCL <cpd>

SAV <nrf>

TRG

Returns the complete set up of t he instrument as a hexadecimal character data block. To r e−install the set up the block should be returned to the instrument exactly as it is received. The syntax of the response is LRN <Character data><rmt>. The sett ings in the

Resets the instrument parameters to their default values (see

Recalls the instrument set up contained in store <nrf>. The store

Saves the complete instrument set up to the set-up file number

This command is the same as pressing t he MAN/SYNC key. Its effect will depend on the context in which it is asserted. The interface command Group Execute Trigger (GET) will perform the s am e action

LOCAL Returns the instrument to local operation and unlocks the keyboard.

Refer to Calibration section for r emote calibration commands.

∗CLS

Clear status.

∗

<nrf>.

∗

in <nr1> numeric format.

∗

numeric format.

∗IDN?

Returns the instrument identif icat ion.

∗IST?

Returns ist local message as defined by IEEE Std. 488.2.

∗

character data block approximately 842 bytes long.

∗

Status Register.

∗OPC?

Query operation complete status.

∗PRE <nrf>

∗

numeric format.

∗RCL <cpd>

∗RST

∗SAV <cpd>

Saves the complete instrument set up store num ber <nrf>.

∗SRE <nrf>

∗

<nr1> numeric format .

∗

format.

∗TRG

∗

always 0<rmt>.

∗

started

ABORT

Aborts a phase locking operation.

AMPUNIT command.

AMPUNIT <cpd>

Set the amplitude units to <VPP>, <VRMS> or <DBM>.

Returns the data from an arbitrary waveform.

and load with the data in <bin data block>.

and load with the data in <csv ascii data>.

ARBLEN? <cpd>

Returns the length, in points, of t he ar bit r ary waveform <cpd>.

BEEP

Set beep mode to <ON>, <OFF>, < WARN>, or <ERROR>.

BEEPMODE <cpd>

Sound one beep.

BSTCNT <nrf>

Set the burst count to <nrf>.

CLKFREQ <nrf>

Set the arbitrary sample clock freq to <nr f> Hz.

Remote Command Summary

ESE <nrf>

ESE?

ESR?

LRN?

OPC

PRE?

Set the Standard Event Status Enable Register to the value of

Returns the value in the Standard Event Status Enable Register

Returns the value in the Standard Event Status Reg ister in <nr1>

Returns the complete set up of t he inst rument as a hexadecimal

Sets the Operation Complete bit (bit 0) in the Standard Event

Set the Parallel Poll Enable Register to the value <nrf>. Returns the value in the Parallel Poll Enable Register in <nr1>

Recalls the instrument set up contained in store <nrf>. Resets the instrument parameters to their default values.

Set the Service Request Enable Register to <nrf>.

SRE?

STB?

TST?

WAI

AMPL <nrf> Set the amplitude to <nrf> in t he units as specified by the

ARBDATA? <cpd> ARBDATACSV? <cpd> ARBDEF

<cpd>,<nrf>,<bin data block> ARBDEFCSV

Returns the value of the Service Request Enable Register in

Returns the value of the Status Byte Register in <nr1> numeric

This command is the same as pressing the MAN/SYNC key. The generator has no self −test capability and the response is

Wait for operation complet e t rue. executed before the next is

Define an arbitrary waveform with name <cpd> and length <nr f>

CLKPER <nrf>

Set the arbitrary sample clock period to <nr f> sec.

DCOFFS <nrf>

Set the dc offset to <nrf> Volts.

EER?

Query and clear execution error number register.

FILTER <cpd>

Set the output filter to < AUTO>, <ELIP>, <BESS> or <NONE> .

FORCETRG

Force a trigger to the selected channel.

keyboard. W ill not function if LLO is in force.

LRN <character data>

Install data for a previous ∗LRN? command.

MOD <cpd>

Set the modulation source to <OFF> or < EXT>.

<TONE>.

MODTYPE <cpd>

Set the modulation type to <AM> or <SCM>.

OUTPUT <cpd>

Set the main output <ON>, <OFF> , <NORMAL> or <INVERT>.

PHASE <nrf>

Set the slave generator phase to <nrf> degrees.

PULSDLY <nrf>

Set the pulse delay to <nrf> sec.

PULSPER <nrf>

Set the pulse period to <nrf> sec.

PULSWI D <nrf>

Set the pulse width to <nrf> sec.

PULTRNBASE <nrf>

Set the pulse−train base line to <nrf > Volts.

PULTRNDLY <nrf1>,<nrf2>

Set the delay of pulse−train pulse number <nrf1> to <nrf2> sec.

PULTRNLEN <nrf>

Set the number of pulses in the pulse−t r ain t o < nr f>.

PULTRNLEV <nrf1>,<nrf2>

Set the level of pulse−train pulse number <nrf1> to <nrf2> Volts.

PULSTRN command.

PULTRNPER <nrf>

Set the pulse−train period to <nrf > s ec.

PULTRNWID <nrf1>,<n rf2>

Set the width of pulse−train pulse number <nrf 1> to <nrf2> sec.

QER?

Query and clear query error number register.

REFCLK <cpd>

Set the ref. clock bnc t o < IN>, <OUT>, <MASTER> or <SLAVE>.

SUM <cpd>

Set the sum source to <OFF> or < EXT>.

SWPCENTFRQ <nrf>

Set the sweep centre frequency to <nrf> Hz.

<UPDN>.

SWPMKR <nrf>

Set the sweep marker to <nrf > Hz.

SWPSPACING <cpd>

Set the sweep spacing to <LIN> or <LOG>.

SWPSPAN <nrf>

Set the sweep frequency span to <nrf> Hz.

SWPSTARTFRQ <nrf>

Set the sweep start frequency to <nrf> Hz.

SWPSTOPFRQ <nrf>

Set the sweep stop frequency to <nrf> Hz.

SWPSYNC <cpd >

Set the sweep sync <ON> or <OFF>.

SWPT IME <nrf>

Set the sweep time to <nrf> sec.

SWPT YPE < c pd >

Set the sweep type to <CONT>, <TRIG> or <THLDRST> .

<SWPSYNC> or <PHASLOC>.

list.

any other value gives Gate type.

LOCAL Returns the instrument to local operation and unlocks the

MODE <cpd> Set the mode to <CONT>, <GATE>, <TRIG>, <SWEEP> or

PULTRNMAKE

Makes the pulse−train and runs it − similar to t he WAVE

SWPDI RN < c p d > Set the sweep direction to <UP>, <DO WN>, <DNUP> or

SYNCOUT <cpd> Set the sync output <ON>, <O FF> , <AUTO>, <WFMSYNC>,

<POSNMKR>, <BSTDONE>, < SEQSYNC>, <TRIGGER>,

TONEEND <nrf> Delete tone frequency number <nrf> thus defining the end of t he

TONEFREQ <nrf1>,<nrf 2> , < nr f3> Set tone frequency number <nrf1> to <nr f2> Hz. The third

parameter sets the tone type; 1 will give Trig, 2 will give FSK,

<POS> or <NEG>.

TRIGLEV <nrf>

Set the trigger thr eshold level to <nrf> Volts.

TRIGPER <nrf>

Set the internal trigger generator period to <nrf> sec.

USBID?

Returns the instruments address.

<NOISE>, <ARB1>. <ARB2>, <ARB3> or <ARB4>.

WAVFREQ <nrf>

Set the waveform frequency to <nr f> Hz.

WAVPER <nrf>

Set the waveform period to <nrf> sec.

or <EXT>.

<OPEN>.

TRIGIN <cpd> Set the trig input to <INT>, <EXT>, <MAN>, <PREV>, <NEXT>,

WAVE <cpd> Select the output waveform as <SINE>, <SQ UARE>,

<TRIANG>, <DC>, <POSRMP>, <NEGRMP>, <COSINE>, <HAVSIN>, <HAVCOS>, <SINC>, <PULSE>, <PULSTRN>,

WFMCLKSRC <cpd> Set the playback c lock source of the selected waveform to <INT>

ZLOAD <cpd> Set the output load, which the generator is to assume for

amplitude and dc offset entries, to < 50> ( 50Ω), <600> (600Ω) or

The Manufacturers or their ag ents overseas will provide a repair service for any unit developing a fault. Where owners wish to undertake their own maintenance work, this should only be done by skilled personnel in conjunction with the service manual which may be purchased directly from the Manufacturers or their agents overseas.

Cleaning

If the instrument r equires cleaning use a cloth that is only lightly dampened with water or a mild detergent.

WARNING! TO AVOID ELECTRIC SHOCK, OR DAMAGE TO THE INSTRUMENT, NEVER ALLOW WATER TO GET INSIDE THE CASE. TO AVOID DAMAGE TO THE CASE NEVER CLEAN WITH SOLVENTS.

Maintenance

No errors or warnings have been reported

DC offset changed by amplitude

Offset + Sum + level may cause clipping

Offset will clip the waveform

Instrument not calibrated

Amplitude will clip the waveform

Trigger source is fixed to external in SLAVE mode

Trigger slope is fixed to positive in SLAVE mode

The programmed mod depth c annot be set

Numeric value too large − switching to sample period

101

Frequency out of range for the selected waveform

102

Sample clock frequency requir ed exceeds 100MHz

103

Sample clock frequency requir ed is less t han 0. 1Hz

104

Pulse/pulse−train period out of rang e for current set−up

105

Pulse width cannot be greater than the period

106

Absolute value of pulse delay must be < period

107

Pulse width cannot be less than 10ns

108

Maximum output level exceeded

109

Minimum output level exceeded

110

Minimum dc offset value exceeded

111

Maximum dc offset value exceeded

112

The value entered is out of range

119

Arb waveform length cannot be less than four points

125

No GPIB available

127

System ram error battery f ault or firmware updated

135

Trigger generator maximum period is 200s

136

Trigger generator minimum per iod is 10us

137

Waveform is not available with ext clock

138

Burst count value exceeds the maximum of 1048575

139

Burst count value cannot be less than 1

140

Trig/Gate freq too hig h. Max=2.5MHz. Continuous mode set

141

Selected function is illegal in tone mode TONE MODE CANCELLED!

144

Selected combination of function and mode is illegal

Appendix 1. Warning and Error Messages

Warning messages are given when a setting may not give the expected result, e.g. DC Offset attenuated by the output attenuator when a small amplitude is set ; the setting is, however, implemented.

Error messages are given when an illegal setting is attempted; the previous setting is retained. The last two warning/error messages c an be r eviewed by selecting LAST ERROR from the

UTILITY screen, the latest is report ed first. Warning and error messages are reported with a number on the display; only the number is

reported via the remote control interfaces. The following is a complete list of messages as they appear on the display.

Warning Messages

Error Messages

145

Locked master/slave is available with continuous mode only

148

Trig/gate mode and seq step value cause a trigger conflict

150

Number of pulses in train must be between 1 and 10

151

Pulse train base level must be >−5.0V and <+5.0V

152

Pulse level must be >−5.0V and <+5.0V

153

Pulse number must be between 1 and 10

154

Sweep frequency values must be 1mHz to 40MHz

155

Sweep start freq must be less than st op freq

156

Sweep stop freq must be greater than start freq

157

Sweep time value is out of range 0.001s < n < 999s

158

Sweep marker value is out of range 0.001Hz < n < 40MHz

160

Not locked. This error indicates that a phase lock ing oper ation has failed.

161

Illegal phase value

184

SUM or Modulation conflict

188

Maximum trigger level is +5.0V

189

Minimum trigge r le vel is –5.0v

Length is different to that in the ARBDEF(CSV) command

120

Waveform limit value out of range

126

Illegal store number request ed

162

Byte value outside the range 0 to 255

163

Specified arb name does not exist

164

Command illegal in sweep or tone mode

166

Cannot set sample frequency or period for std waveforms

167

dBm output units assume a 50 Ohm termination

168

Specified units illegal for the selected waveform

169

Command not available for RS232

170

Length value error in binary block

171

Illegal value in arbitrary data

173

Illegal tone number

177

Illegal remote calibration command.

185

Command not available while sweeping.

201

CRITICAL STOP! Fault in clock circuit of channel <chan> - possible hardware failure

202

CRITICAL STOP! Fault in calibration flash memory block - flash write fault

205

CRITICAL STOP! Stack Overflow - firmware error

206

CRITICAL STOP! Stack Underflow - firmware error

207

CRITICAL STOP! Illegal instruction - firmware error

208

CRITICAL STOP! Illegal NMI - firmware error

209

CRITICAL STOP! Heap overflow - f irmware error

Remote Warnings

Remote Errors

Critical Stop Errors

These errors have no obvious recovery path and require user intervention. Some can be bypassed by a key press, some offer a choice of action. Possible hardware f ailures m ay be firmware induced and recover by cycling the power. Firmware error s all require a power cycle to recover.

Any of these errors may indicate an imminent system failure or a firmware bug.

MODE

WAVEFORM

Sync

Done

Trigger

Lock

Continuous

All

Gate/Trig

All

Sweep

All



Tone

All

Appendix 2. SYNC OUT Automatic Settings

The following automatic source (src) set tings are made when auto mode is selected on the SYNC OUT

master/slave All

screen.

Waveform



Burst



Sweep

Phase



Main Parameters

Std. Wave:

Sine

Frequency:

10kHz

Output:

+2·0Vpp

; Output Off

DC Offset:

0V Zout:

HiZ

Gate/Trigger Parameters

Source:

Internal

Period:

1ms

Slope:

Positive

Burst Count:

1 Phase

0deg

Modulation Parameters

Source:

Off Type:

VCA

Sum:

Off

Sweep Parameters

Begin Frequency:

100kHz

End Frequency:

40MHz

Marker Frequency:

10MHz

Direction:

Up Spacing:

Log

Sweep Time:

10ms

Type:

Continuous

Filter

Auto

Sync Out

Auto

Arbitrary

All unaffected by reset or ∗RST.

Appendix 3. Factory System Defaults

The factory system defaults are list ed in full below. They can be recalled by pressing RECALL followed by set defaults or by the remote command ∗RST. All channels will be receive the same setup. All channels default to the same settings.

Appendix 4. Waveform Manager Plus Arbitrary

Waveform Creation and Management

Software

The Thurlby Thandar Waveform Manager Plus program allows construction, editing, exchange, translation and storage of m any types of waveform data. It is compatible with many popular DSOs and all TTi waveform generation produc ts.

Waveforms may be generated by equation entry, freehand drawing, combining existing waveforms or any combinations of these methods.

Data upload and download are possible via RS232 (COM1-4), USB or GPIB subject to a compatible GPIB card being correctly installed and configured in your PC.

Both upload and download of waveform data are possible and, where applicable, data exchange via 3.5 in floppy disks in the Tektronix *.I SF format is available.

Text data may be read from the Windows clipboard and used to create a waveform. The text data format is very free and will allow most lists of numbers, with or without intervening text, to be read as waveform data points. Waveform data may also be pasted to the clipboard for insertion into other programs.

Waveforms are displayed in fully scaleable windows and may be manipulated graphically. Any number of waveforms in any of the support ed types may be displayed simultaneously.

On-line help is available in three ways.

1. The help menu contains a contents option from which you can go to any section of the on-line help file or browse particular areas or the whole file. It is also possible to use the Index and Find operations of the Windows help system to search for items which are not listed directly in the contents section.

2. Some dialog boxes have a Help button which, when clicked, will open the on-line help file at the section containing the description of that dialog box.

3. Fr om m ost windows/dialogues the F1 key will open the help file at the relevant section.

Waveform Manager allows you to keep waveforms for different projects separate from each ot her on your hard drive. A project may be placed anywhere, in any directory (folder ) and all waveform files for that proj ec t will be stored in a str ucture below that directory. A project is identif ied by a user defined name. Each project m aintains its own library of expressions.

Ltd

)

Thurlby Thandar Instruments

Glebe Road • Huntingdon • Cambridgeshire • PE29 7DR • England (United Kingdom

Telephone: +44 (0)1480 412451 • Fax: +44 (0)1480 450409

International web site:

www

.aimtti.com • UK web site:

www

.aimt t i.co.uk

Email: info@aimtti.com

Aim Instruments and Thurlby Thandar Instruments Book Part No. 48591-1080 Issue 5

Thurlby Thandar Instruments TG4001 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

Sine, Cosine, Haversine, Havercosine

Square

Triangle

Ramps and Sin(x)/x

Pulse and Pulse Train

Arbitrary

Output Filter

Noise

Gated

Sweep

Tone Switching

Trigger Generator

Sync Out

Modulation In

Sum In

Ref Clock In/Out

INTERFACES

GENERAL

Emissions

Immunity

Cautions

Mains Operating Voltage

Fuse

Mains Lead

Mounting

Ventilation

Front Panel Connec tions

MAIN OUT

SYNC OUT

TRIG IN

Rear Panel Connections

MODULATION IN

SUM IN

REF CLOCK IN/OUT

MAIN OUT

RS232

Initial Operation

Switching On

Display Contrast

Keyboard

Principles of Editing

Principles of Operation

Clock Synthesis Mode

DDS Mode

Setting Generator Parameters

Waveform Selection

Frequency

Amplitude

DC Offset

Warnings and Error Messages

SYNC Output

General

Principles of Sweep Operation

Connections for Sweep Operation. Sync Out and Trig In

Setting Sweep Parameters

Sweep Range

Sweep Time

Sweep Type

Sweep Spacing

Sweep Marker

General

Internal Trigger Generator

External Trigger Input

Triggered Burst

Trigger Source

Trigger Edge

Burst Count

Start Phase

Gated Mode

Gate Source

Gate Polarity

Start Phase

Sync Out in Triggered Burst and Gated Mode

General

Tone Frequency

Tone Type