TTI TGA1230 User manual

TGA1230
30 MHz Synthesised Arbitrary
Waveform Generator
User Manual
Manual Copyright © 1997 T T Instruments Ltd. All rights reserved.
Software Copyright © 1997 T T Instruments Ltd. All rights reserved.
WaveCAD Copyright © 1997 Tabor Electronics. All rights reserved.
Book Part Number 48591 - 0510 Issue 4.

Contents
Introduction 3
Specifications 4
Safety 11
EMC 12
Installation 12
Connections 14
Front Panel Connections 14
Rear Panel Connections 15
General 17
Initial Operation 17
Principles of Operation 19
Standard Waveform Operation 21
Setting Generator Parameters 21
Warnings and Error Messages 24
SYNC Output 25
Sweep Operation 26
General 26
Setting Sweep Parameters 27
Triggered Burst and Gate 30
General 30
Triggered Burst 31
Gated Mode 32
Sync Out in Triggered Burst and Gated Mode 32
Tone Mode 33
Other Modulation Modes 35
External VCA 35
External SUM In 35
Amplitude Range for Each Attenuator Step 36
Arbitrary Waveform Generation 37
Introduction 37
Creating New Waveforms 38
Modifying Arbitrary Waveforms 39
Arbitrary Waveform Sequence 44
Frequency and Amplitude Control with Arbitrary Waveforms 45
Sync Out Settings with Arbitrary Waveforms 46
Waveform Hold in Arbitrary Mode 47
1

Output Filter Setting 47
WaveCAD Arbitrary Waveform Creation Software 48
Pulse and Pulse-trains 50
Pulse Set-up 50
Pulse-train Setup 51
Waveform Hold in Pulse and Pulse-Train Modes 53
Synchronising Generators 54
System Operations from the Utility Menu 56
Calibration 59
Equipment Required 59
Calibration Procedure 59
Calibration Routine 60
Remote Calibration 61
Remote Operation 62
Address and Baud Rate Selection 62
Remote/Local Operation 62
ARC Interface 63
GPIB Interface 65
Power on Settings 67
Status Reporting 67
ARC Remote Command Formats 70
GPIB Remote Command Formats 70
Remote Commands 72
Frequency and Period 72
Amplitude and DC Offset 72
Waveform Selection and Definition 73
Waveform Sequence Control 74
Arbitrary Waveform Editing 75
Mode Commands 76
Input/Output control 76
Status Commands 77
Miscellaneous Commands 78
Remote Command Summary 79
Maintenance 82
Appendix 1. Warning and Error Messages 83
Appendix 2. SYNC OUT Automatic Settings 86
Appendix 3. Factory System Defaults 87
2

Introduction
This Synthesised Programmable Arbitrary Waveform Generator uses a combination of direct
digital synthesis and phase lock loop techniques to provide high performance and extensive
facilities in a compact instrument. It can generate a wide variety of waveforms between 0·1mHz
and 15MHz with high resolution and accuracy.
Arbitrary waveforms may be defined with 12 bit vertical resolution and from 4 to 65536 horizontal
points. In addition a number of standard waveforms are available including sine, square, triangle,
ramp and pulse.
Arbitrary waveforms may be replayed at a user specified waveform frequency or period, or the
sample rate may be defined in terms of period or frequency.
Extensive waveform editing features between defined start and end points are incorporated,
including waveform insert, point edit, line draw, amplitude adjust and invert. More comprehensive
features are available using the WaveCAD arbitrary waveform creation software supplied.
WaveCAD is a powerful Windows-based design tool that enables the user to create waveforms
from mathematical expressions, from combinations of other waveforms, freehand, or using a
combination of all three techniques. Waveforms created in this way are downloaded via the
RS232 or optional GPIB interface.
Up to 50 waveforms may be stored with the length and name specified by the user. Waveforms
may be strung together to form a sequence of up to four steps. Each waveform may have a user
defined repeat count from 1 to 32768.
All waveforms can be swept over their full frequency range at a rate variable between 30
milliseconds and 15 minutes. Sweep can be linear or logarithmic, single or continuous. Single
sweeps can be triggered from the front panel, the trigger input, or the digital interfaces. A sweep
marker is provided.
Amplitude Modulation is available for all waveforms and is controlled from an external generator
via the Ext VCA input.
All waveforms are available as a Triggered Burst whereby each active edge of the trigger 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 signal On when the gating signal is true and Off when
it is false. Both Triggered and Gated modes can be operated from the internal Trigger Generator
(0.005Hz to 50kHz), from an external source (dc to 1MHz) or by a key press or remote command.
The signals from the REF IN/OUT socket and the SYNC OUT socket can be used to phase lock
two or more generators. This can be used to generate multi-phase waveforms or locked
waveforms of different frequencies.
The generator parameters are clearly displayed on a backlit LCD with 4 rows of 20 characters.
Soft-keys and sub menus are used to guide the user through even the most complex functions.
All parameters can be entered directly from the numeric keypad. Alternatively most parameters
can be incremented or decremented using the rotary control. This system combines quick and
easy numeric data entry with quasi-analogue adjustment when required.
The generator has an RS-232 interface as standard which can be used for remote control of all of
the instrument functions or for the down-loading of arbitrary waveforms.
As well as operating as a conventional RS-232 interface, it can also be used in addressable
mode whereby up to 32 instruments can be linked to one PC serial port as part of a TTi "ARC"
system. Alternatively, a GPIB interface conforming to IEEE-488.2 is available as an option.
3

Specifications
Specifications apply at 18-28ºC after one hour 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 and havercosine.
Sine, Cosine, Haversine, Havercosine
Range: 0·1 mHz to 10 MHz.
Resolution: 0·1mHz (7 digits).
Accuracy: 10 ppm for 1 year.
Temperature Stability: Typically <1 ppm/ºC.
Output Level: 5mV to 20V pk-pk from 50Ω.
Harmonic Distortion: <0.1% THD to 100kHz; <–65dBc to 20kHz,
<–50dBc to 1MHz, <–35dBc to 10MHz.
Non-harmonic Spurii: <–65dBc to 1MHz, <–65dBc + 6dB/octave 1MHz to 10MHz.
Square
Range: 1 mHz to 15MHz.
Resolution: 1mHz (4 digits)
Accuracy: ± 1 digit of setting.
Output Level: 5mV to 20V pk-pk from 50Ω.
Rise and Fall Times: <25ns
Triangle
Range: 0.1 mHz to 100kHz.
Resolution: 0.1mHz (7 digits)
Accuracy: 10 ppm for 1 year.
Output Level: 5mV to 20V pk-pk from 50Ω.
Linearity Error: <0.1% to 30 kHz
Ramps and Sin(x)/x
Range: 0.1 mHz to 100kHz.
Resolution: 0.1mHz (7 digits)
Accuracy: 10 ppm for 1 year.
Output Level: 5mV to 20V pk-pk from 50Ω.
Linearity Error: <0.1% to 30 kHz
Pulse and Pulse Train
Output Level: 5mV to 20V pk-pk from 50Ω.
Rise and Fall Times: <25ns
4

Period:
Range: 133·3ns to 100s.
Resolution: 4-digit.
Accuracy: ±1 digit of setting.
Delay:
Range:
Resolution:
-99·9s to + 99·99s
0·002% of period or 33·33ns, whichever is greater.
Width:
Range:
Resolution:
33·3ns to 99·99s
0·002% of period or 33·33ns, whichever is greater.
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 50 user defined waveforms may be stored in RAM. Waveforms can be defined by front
panel editing controls or by downloading of waveform data via RS232 or GPIB.
Waveform Memory Size: 64k points. Maximum waveform size is 64k points, minimum
waveform size is 4 points.
Vertical Resolution: 12 bits
Sample Clock Range: 100mHz to 30MHz
Resolution: 4 digits
Accuracy: ± 1 digit of setting.
Sequence
Up to 4 waveforms may be linked. Each waveform can have a loop count of up to 32768.
A sequence of waveforms can be looped up to 1048575 times or run continuously.
Output Filter
Selectable between 10MHz Elliptic, 10MHz Bessel or none.
MODULATION MODES
Triggered Burst
Each active edge of the trigger signal will produce one burst of the waveform, starting and
stopping at the waveform position specified by the sync marker setting.
Carrier Waveforms: All standard and arbitrary
Number of Cycles: 1 to 1048575
Trigger Repetition Rate: dc to 50 kHz internal, dc to 1MHz external.
Source: Internal from keyboard or trigger generator.
External from TRIG IN or remote interface.
5

Gated
Waveform will run while the Gate signal is true and stop while false.
Carrier Waveforms: All standard and arbitrary.
Trigger Repetition Rate: dc to 50 kHz internal, dc to 1 MHz external.
Gate Signal Source: Internal from keyboard or trigger generator.
External from TRIG IN or remote interface.
Sweep
Capability 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.
Carrier Waveforms: All standard and arbitrary except pulse, pulse train and sequence.
Sweep Mode: Linear or logarithmic, up or down, triggered or continuous.
Sweep Range: From 1mHz to 10 MHz in one range. Phase continuous.
Independent setting of the start and stop frequency.
Sweep Time: 30ms to 999s (3 digit resolution).
Marker: Variable during sweep.
Sweep Trigger Source: The sweep may be free run or triggered from the following sources:
Manually from keyboard. Externally from TRIG IN input or remote
interface.
Sweep Hold: Sweep can be held and restarted by the HOLD key.
Tone
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.
Carrier Waveforms: All waveforms except pulse, pulse train and sequence.
Frequency List: Up to 16 frequencies from 1mHz to 10MHz.
Switching Sources: External trigger input. A true level will output the tone, a false level
will stop the tone and switch to the next frequency on the list ready
for the next true level.
Min. switch time: 20ms per tone.
Using 2 instruments with their outputs summed together it is possible to generate DTMF test
signals.
External Amplitude Modulation
Carrier frequency: Entire range for selected waveform.
Carrier waveforms: All standard and arbitrary waveforms
Modulation source: VCA/SUM IN socket.
Frequency Range: DC - 100 kHz.
Signal Range: Approximately 2·5V pk-pk for 100% level change at maximum
output.
6

External Signal Summing
Carrier frequency: Entire range for selected waveform.
Carrier waveforms: All standard and arbitrary waveforms.
Sum source: VCA/SUM IN socket.
Frequency Range: DC to 10MHz.
Signal Range: Approximately 5Vpk-pk input for 20Vpk-pk output.
Trigger Generator
Internal source 0.005 Hz to 50kHz squarewave adjustable in 20us steps. 3 digit resolution.
Available for external use from the SYNC OUT socket.
OUTPUTS
Main Output
Output Impedance: 50Ω
Amplitude: 5mV to 20V pk-pk open circuit (2.5mV to 10V pk-pk into 50Ω).
Amplitude can be specified open circuit (hi Z) or into an assumed
load of 50Ωor 600Ωin Vpk-pk, Vrms or dBm.
Amplitude Accuracy: 2% ±1mV at 1kHz into 50Ω.
Amplitude Flatness: ±0.2dB to 200 kHz; ±1dB to 5 MHz; ±2dB to 10 MHz.
DC Offset Range: ±10V. DC offset plus signal peak limited to ±10V from 50Ω.
DC Offset Accuracy: Typically 3% ±10mV, unattenuated.
Resolution: 3 digits for both Amplitude and DC Offset.
Sync Out
Multifunction output user definable or automatically selected to be any of the following:
Waveform Sync:
(all waveforms)
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.
Position Markers:
(Arbitrary only)
Any point(s) on the waveform may have associated marker bit(s)
set high or low.
Burst Done: Produces a pulse coincident with the last cycle of a burst.
Sequence Sync: Produces a pulse coincident with the end of a waveform
sequence.
Trigger: Selects the current trigger signal. Useful for synchronising burst
or gated signals.
Sweep Sync: Outputs a pulse at the start of sweep to synchronise an
oscilloscope or recorder.
Phase Lock Out: Used to phase lock two or more generators. Produces a positive
edge at the 0° phase point.
Output Signal Level: TTL/CMOS logic levels from typically 50Ω.
7

Cursor/Marker Out
Adjustable output pulse for use as a marker in sweep mode or as a cursor in arbitrary waveform
editing mode. Can be used to modulate the Z-axis of an oscilloscope or be displayed on a second
‘scope channel.
Output Signal Level: Adjustable from nominally 2V to 14V, normal or inverted; adjustable
width as a cursor.
Output Impedance: 600Ωtypical
INPUTS
Trig In
Frequency Range: DC - 1MHz.
Signal Range: Threshold nominally TTL level; maximum input ±10V.
Minimum Pulse Width: 50ns, for Trigger and Gate modes; 50us for Sweep mode; 20ms for
Tone mode.
Input Impedance: 10kΩ
VCA In
Frequency Range: DC - 100kHz.
Signal Range: 2.5V for 100% level change at maximum output.
Input Impedance: Typically 6kΩ.
Sum In
Frequency Range: DC - 10MHz.
Signal Range: Approximately 5Vpk-pk input for 20Vpk-pk output.
Input Impedance: Typically 1k2Ω.
Hold
Holds an arbitrary waveform at its current position. A TTL low level or switch closure causes the
waveform to stop at the current position and wait until a TTL high level or switch opening which
allows the waveform to continue. The front panel HOLD key or remote command may also be
used to control the Hold function. While held a rising edge at TRIG IN will return the waveform to
the start. The front panel MAN/SYNC key or remote command may also be used to return the
waveform to the start.
Input Impedance: 10kΩ
Ref Clock In/Out
Set to Input: Input for an external 10MHz reference clock. TTL/CMOS threshold
level.
Set to Output: Buffered version of the internal 10MHz clock. Output levels
nominally 1V and 4V from 50Ω.
Set to Phase Lock: Used together with SYNC OUT on a master and the TRIG IN on a
slave to synchronise (phase lock) multiple instruments.
8

INTERFACES
Full remote control facilities are available through the RS232 (standard) or optional GPIB
interfaces.
RS232: Variable Baud rate, 9600 Baud maximum. 9-pin D-connector.
Fully compatible with Thurlby-Thandar ARC (Addressable
RS232 Chain) system.
IEEE-488: Conforming with IEEE488.1 and IEEE488.2
GENERAL
Display: 20 character x 4 row alphanumeric LCD.
Data Entry: Keyboard selection of mode, waveform etc.; value entry direct
by numeric keys or by rotary control.
Stored Settings: Up to 9 complete instrument set-ups may be stored and
recalled from battery-backed memory. Up to 50 arbitrary
waveforms can also be stored independent of the instrument
settings.
Size: 3U (130mm) height; half-rack (212mm) width; 330mm long.
Weight: 4.1kg. (9lb.)
Power: 100V, 110V-120V or 220V-240V AC ±10%, 50/60Hz,
adjustable internally; 40VA 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 Degree 2.
Options: IEEE-488 interface; 19 inch rack mounting kit.
Safety: Complies with EN61010-1.
EMC: Complies with EN61326.
9

EC Declaration of Conformity
We Thurlby Thandar Instruments Ltd
Glebe Road
Huntingdon
Cambridgeshire PE29 7DR
England
declare that the
TGA1230 30MHz Synthesised Arbitrary Waveform Generator with GPIB
meets the intent of the EMC Directive 89/336/EEC and the Low Voltage Directive 73/23/EEC.
Compliance was demonstrated by conformance to the following specifications which have been
listed in the Official Journal of the European Communities.
EMC
Emissions: a) EN61326 (1998) Radiated, Class B
b) EN61326 (1998) Conducted, Class B
c) EN61326 (1998) Harmonics, referring to EN61000-3-2 (2000)
Immunity: EN61326 (1998) Immunity Table 1, Performance B, referring to:
a) EN61000-4-2 (1995) Electrostatic Discharge
b) EN61000-4-3 (1997) Electromagnetic Field
c) EN61000-4-11 (1994) Voltage Interrupt
d) EN61000-4-4 (1995) Fast Transient
e) EN61000-4-5 (1995) Surge
f) EN61000-4-6 (1996) Conducted RF
Safety
EN61010-1 (1993) Installation Category II, Pollution Degree 2.
CHRIS WILDING
TECHNICAL DIRECTOR
2 July 2001
10

Safety
This generator is a Safety Class I instrument according to IEC classification and has been
designed to meet the requirements of EN61010-1 (Safety Requirements for Electrical Equipment
for Measurement, Control and Laboratory Use). It is an Installation Category II instrument
intended for operation from a normal single phase supply.
This instrument has been tested in accordance 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 retain the instrument in a safe condition.
This instrument has been designed for 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°C and –10°C without degradation of its safety. Do not
operate while condensation is present.
Use of this instrument in a manner not specified by these instructions may impair the safety
protection provided. Do not operate the instrument outside its rated supply voltages or
environmental range.
WARNING! THIS INSTRUMENT MUST BE EARTHED
Any interruption of the mains earth conductor inside or outside the instrument will make the
instrument dangerous. Intentional 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, maintenance 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 defective, 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 for
replacement. The use of makeshift fuses and the short-circuiting of fuse holders is prohibited.
This instrument uses a Lithium button cell for non-volatile memory battery back-up; typical life is 5
years. In the event of replacement becoming necessary, replace only with a cell of the correct
type, i.e. 3V Li/Mn0220mm button cell type 2032. Exhausted cells must be disposed of carefully
in accordance with local regulations; do not cut open, incinerate, expose to temperatures 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 the instrument and in this manual:-
Caution -refer to the accompanying documentation, incorrect operation may
damage the instrument.
terminal connected to chassis ground.
mains supply OFF.
l mains supply ON.
alternating current.
11

EMC
This instrument has been designed to meet the requirements of the EMC Directive 89/336/EEC.
Compliance was demonstrated by meeting the test limits of the following standards:
Emissions
EN61326 (1998) EMC product standard for Electrical Equipment for Measurement, Control and
Laboratory Use. Test limits used were:
a) Radiated: Class B
b) Conducted: Class B
c) Harmonics: EN61000-3-2 (2000) Class A; the instrument is Class A by product category.
Immunity
EN61326 (1998) EMC product standard for Electrical Equipment for Measurement, Control and
Laboratory Use.
Test methods, limits and performance achieved were:
a) EN61000-4-2 (1995) Electrostatic Discharge: 4kV air, 4kV contact, Performance A.
b) EN61000-4-3 (1997) Electromagnetic Field, 3V/m, 80% AM at 1kHz, Performance A.
c) EN61000-4-11 (1994) Voltage Interrupt, 1 cycle, 100%, Performance B*.
d) EN61000-4-4 (1995) Fast Transient, 1kV peak (AC line), 0.5kV peak (signal lines and
RS232/GPIB ports), Performance A.
e) EN61000-4-5 (1995) Surge, 0.5kV (line to line), 1kV (line to ground), Performance A.
f) EN61000-4-6 (1996) Conducted RF, 3V, 80% AM at 1kHz (AC line only; signal
connections <3m not tested), Performance A.
According to EN61326 the definitions of performance criteria are:
Performance criterion A: ‘During test normal performance within the specification limits.’
Performance criterion B: ‘During test, temporary degradation, or loss of function or
performance which is self-recovering’.
Performance criterion C: ‘During test, temporary degradation, or loss of function or
performance which requires operator intervention or system reset occurs.’
*Note: To achieve Performance B it is necessary to set the instrument such that ‘power down’
settings are restored at power up; set the POWER ON SETTING to restore last setup on
the Utility menu.
Cautions
To ensure continued compliance with the EMC directive the following precautions should be
observed:
a) connect the generator to other equipment using only high quality, double-screened cables.
b) after opening the case for any reason ensure that all signal and ground connections are
remade correctly before replacing the cover. Always ensure all case screws are correctly
refitted and tightened.
c) In the event of part replacement becoming necessary, only use components of an identical
type, see the Service Manual.
Installation
Check that the instrument operating voltage marked on the rear panel is suitable for the local
supply. Should it be necessary to change the operating voltage, proceed as follows:
1) Disconnect the instrument from all voltage sources.
2) Remove the screws which retain the top cover and lift off the cover.
3) Change the transformer connections as follows:
12

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
4) Refit the cover and the secure with the same screws.
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 rating, see below.
Fuse
Ensure that the correct mains fuse is fitted for the set operating voltage. The correct mains fuse
types are:
for 230V operation: 250 mA (T) 250 V HRC
for 100V or 115V operation: 500 mA (T) 250 V HRC
To replace the fuse, disconnect the mains lead from the inlet socket and release the fuse drawer
below the socket pins by depressing both clips together, with miniature screwdrivers, so that the
drawer can be eased open. Change the fuse and replace the drawer.
The use of makeshift fuses or the short-circuiting of the fuse holder is prohibited.
Mains Lead
When a three core mains lead with bare ends is provided it should be connected as follows:-
Brown - Mains Live
Blue - Mains Neutral
Green / Yellow - Mains Earth
WARNING! THIS INSTRUMENT MUST BE EARTHED
Any interruption of the mains earth conductor inside or outside the instrument will make the
instrument dangerous. Intentional interruption is prohibited. The protective action must not be
negated by the use of an extension cord without a protective conductor.
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 one or two of these Half-width 3U high units in a 19” rack is available from
the Manufacturers or their overseas agents.
13

Connections
Front Panel Connections
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 external voltages to this output.
SYNC OUT
This is a TTL/CMOS level output which may be set to any of the following signals from the SYNC
OUTPUT SET-UP screen.
WAVEFORM SYNC A sync marker phase coincident with the MAIN OUT waveform. For
standard waveforms, (sine, cosine, haversines, square, 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 falling edge at the 180º
phase point. For arbitrary waveforms the sync marker is a positive
pulse coincident with the first few points (addresses) of the waveform.
In a sequence each waveform in the sequence generates its own sync
marker.
POS’N MARKER When position (pos’n) marker is selected, the instrument generates a
pulse marker pattern for arbitrary waveforms. The pulse pattern is
programmable from the “edit waveform” menu on the MODIFY
screen.
BURST DONE Provides a signal during Gate or Trigger modes which is low while the
waveform is active at the main output and high at all other times.
SEQUENCE SYNC Provides a signal which is low during the last cycle of the last
waveform in a sequence and high at all other times.
TRIGGER Provides a positive going version of the actual trigger signal; internal,
external, manual and remote all produce a trigger sync.
SWEEP SYNC Goes high at the start of the sweep and low at the end of the sweep.
PHASE LOCK Produces a positive edge coincident with the start of the current
waveform; this is used for phase locking instruments. This waveform
may not appear coherent.
SYNC OUT logic levels are nominally 0V and 5V from typically 50 Ω. SYNC OUT will withstand a
short circuit.
Do not apply external voltage to this output.
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 another (which is the master).
Do not apply external voltages exceeding ±10V.
14

VCA/SUM IN
This is the input socket for external voltage controlled amplitude (VCA) or external signal
summing (SUM). The function of this input is selected from the EXT SUM/VCA SET-UP screen.
For VCA operation the input impedance is nominally 6kΩ and for SUM operation it is nominally
1k2Ω.
Do not apply external voltages exceeding ±10V.
Rear Panel Connections
REF CLOCK IN/OUT
The function of the CLOCK IN/OUT socket is set from the “ref clock i/o” menu on the UTILITY
screen, see System Operations section.
INPUT This is the default setting. The socket becomes an input for an external
10MHz reference clock. The system automatically switches over from the
internal clock when the external reference is applied.
OUTPUT The internal 10MHz clock is made available at the socket.
PHASE LOCK When two or more generators are synchronised the slaves are set to PHASE
LOCK SLAVE and the master is set to PHASE LOCK MASTER.
As an output the logic levels are nominally 1V and 4V from typically 50Ω. CLOCK OUT will
withstand a short-circuit. As an input the threshold is TTL/CMOS compatible.
Do not apply external voltages to this output exceeding +7·5 V or -2·5 V.
HOLD IN
Controls the waveform hold function. The input impedance is nominally 10kΩ.
Do not apply external voltages exceeding ±10V.
CURSOR/MARKER OUT
Output pulse for use as a marker in sweep mode or as a cursor in arbitrary waveform editing
mode. Can be used to modulate the Z-axis of an oscilloscope or be displayed on a second ‘scope
channel. The output impedance is nominally 600Ωand the signal level is adjustable from 2V-14V
nominal from the “cursor/marker” menu on the UTILITY screen, see System Operations section.
Do not apply external voltages to this input.
RS232
9-pin D-connector compatible with the Thurlby Thandar ARC (Addressable RS232 Chain)
system. The pin connections are shown below:
Pin Name Description
1 - No internal Connection
2 TXD Transmitted data from instrument
3 RXD Received data to instrument
4 - No internal connection
5 GND Signal ground
6 - No internal connection
7 RXD2 Secondary received data
8 TXD2 Secondary transmitted data
9 GND Signal ground
15

Pin 2, 3 and 5 may be used as a conventional RS232 interface with XON/XOFF handshaking.
Pins 7,8 and 9 are additionally used when the instrument is connected to the ARC interface.
Signal grounds are connected to instrument ground. The ARC address is set from the “remote”
menu on the UTILITY screen, see System Operations section.
GPIB (IEEE-488)
The GPIB interface is an option. It is not isolated; the GPIB signal grounds are connected to the
instrument ground.
The implemented subsets are:
SH1 AH1 T6 TE0 L4 LE0 SR1 RL1 PP1 DC1 DT1 C0 E2
The GPIB address is set from the “remote” menu on the UTILITY screen, see System Operations
section.
16

General
Initial Operation
This section is a general introduction to the organisation of the instrument and is intended to be
read before using the generator 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 shown in capitals, e.g. CREATE, SYNC OUT; all
soft-key labels, entry fields and messages displayed on the LCD are shown in a different type-
font, e.g. STANDARD WAVEFORMS, sine.
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 SYSTEM RAM ERROR, CHECK BATTERY will be
displayed, see the Warnings and Error Messages section.
Loading takes a few seconds, after which the STATUS screen is displayed, showing the
generator parameters set to their default values, with the MAIN OUT set off. Refer to the Utility
screen section for how to change the power up settings to either those at power down or to any
one of the stored settings. Recall the STATUS screen at any time with the STATUS key; a second
press returns the display to the previous screen.
Change the basic generator parameters as described in the Standard Waveform Operation
section and switch the output on with the MAIN OUT key; the ON lamp will light to show that
output is on.
Display Contrast
All parameter settings are displayed on the 20 character x 4 row backlit liquid crystal display
(LCD). The contrast may vary a little with changes of ambient temperature 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 marked LCD and rotate the
control for optimum contrast.
Keyboard
Pressing the front panel keys displays screens which list parameters or choices relative to the
key pressed. Selections are then made using the display soft-keys and numeric values are
changed using the numeric keys or rotary control, see the Principles of Editing section.
The keys are grouped as follows:
• WAVE SELECT keys call screens from which all standard or already defined arbitrary
waveforms can be selected and from which sweep parameters can be set.
• WAVE EDIT keys call screens from which arbitrary waveforms can be created and modified
and output filter selected.
• 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 three formats: integer (20), floating point (20·0) and exponential (2 exp 1). For
example, to set a new frequency of 50kHz press FREQ followed by 50000 ENTER or
5 EXP 4 ENTER. ENTER confirms the numeric entry and changes the generator setting to
the new value.
CE (Clear Entry) undoes a numeric entry digit by digit. ESCAPE returns a setting being edited
to its last value.
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• VCA/SUM IN, TRIG IN and SYNC OUT call screens from which the parameters of those
input/outputs can be set, including whether the port is on or off; the MAIN OUT key simply
switches the main output on or off.
• MAN/SYNC is used for manual triggering (when TRIG IN is appropriately set) and for
synchronising two or more generators when suitably connected together. HOLD is used to
manually pause arbitrary waveform output and sweep; the output is held at the level it was at
when HOLD was pressed.
• 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/recall waveforms to/from non-
volatile memory; the RECALL key can also be used to directly access the non-volatile stores.
• Eight soft-keys around the display are used to directly set or select parameters 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 STATUS again returns the display to the previous
screen.
Further explanations will be found in the detailed descriptions of the generator’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 numeric keyboard entry; choices are made
using the soft-key associated with the screen item to be selected. The examples which follow
assume factory default settings.
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
◊triggered setup…◊
The filled diamond indicates that the selected mode 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 continuous hollow. This screen 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 the MODE screen illustrated, pressing the
setup… soft-key brings up the TRIGGER SETUP menu; note that selecting this item does not
change the continuous/gated/triggered selection.
Some screen items are marked with a double-headed arrow (a split diamond) when selected to
indicate that the item’s setting can be changed by further presses of the soft-key, by pressing
either cursor key or by using the rotary control. For example, pressing FILTER brings up the
screen shown below.
FILTER SETUP
mode: auto
◊type: 10MHz eliptic
Repeated presses of the mode soft-key will toggle the mode between its two possible settings
of auto and manual. Similarly, when type is selected, repeated presses of the type soft-
key (or cursor keys or use of the rotary control) will step the selection through all possible settings
of the filter type.
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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. items 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 STD (standard waveform) and UTILITY screens.
In screens where a parameter with a numeric value is displayed the cursor keys move the edit
cursor (a flashing underline) through the numeric field and the rotary control will increment or
decrement the value; the step size is determined by the position of the edit cursor within the
numeric field.
Thus for STANDARD FREQUENCY set to 1.00000 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 increment 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
1.000000 kHz.
This is the limit because to show a lower frequency the display would need to autorange below
1kHz to xxx.xxx Hz in which the most significant digit represents 100Hz, i.e. the 1kHz
increment would be lost. If, however, the starting frequency had been set to 1.000000 MHz, i.e.
a 100 Hz increment, the display would have autoranged at 1kHz to 900.0000 Hz and could
then be decremented further right down to 000.0000 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, sinx/x and ramp waveforms. Clock
Synthesis mode is used for square, pulse, pulse train, arbitrary and sequence.
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 filtered 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.
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