Thurlby Thandar Instruments TG2000, TG1000 User Manual
THURLBY THANDAR INSTRUMENTS
INSTRUCTION MANUAL
TG1000 & TG2000
DDS Function Generators
Table of Contents
Introduction 2
Specifications 3
Safety 6
EMC 8
Installation 9
Connections 10
Front Panel Connections 10
Rear Panel Connections 11
General 12
Initial Operation 12
Standard Waveform Operation 15
Setting Generator Parameters 15
AUX Output 18
Warnings and Error Messages 19
Sweep Operation 20
General 20
Setting Sweep Parameters 20
Gated Mode 25
Tone Mode 26
FSK 27
Modulation 28
System Operations from the Utility Menu 29
Calibration 31
Equipment Required 31
Calibration Procedure 31
Calibration Routine 32
Remote Calibration 33
Remote Operation 34
USB Interface 38
Remote Commands 39
Maintenance 42
Appendix 1. Warning and Error Messages 43
Appendix 2. Factory System Defaults 44
1
This manual is for both the TG2000 and TG1000 function generators. The TG1000 has a
maximum frequency of 10MHz and no remote control capability but is otherwise functionally the
same as the TG2000 20MHz generator. Wherever there are differences in the specification or
operation, the limits for the TG1000 are shown in square brackets [ ] after the TG2000 limits.
This function generator uses direct digital synthesis to provide high performance and extensive
facilities at a breakthrough price. It can generate a variety of waveforms between 1mHz and
20MHz [10MHz] with a resolution of 6 digits and an accuracy better than 10ppm.
Direct digital synthesis for accuracy & stability
Direct digital synthesis (DDS) is a technique for generating waveforms digitally using a phase
accumulator, a look-up table and a DAC. The accuracy and stability of the resulting waveforms is
related to that of the crystal master clock.
The DDS generator offers not only exceptional accuracy and stability but also high spectral purity,
low phase noise and excellent frequency agility.
A wide range of waveforms
High quality sine, square and pulse waveforms can be generated over the full frequency range of
1mHz to 20MHz [10MHz].
Introduction
Triangle waveforms can also be generated but with limitations as to the maximum usable
frequency.
Variable symmetry/duty-cycle is available for squarewave and pulse waveforms.
Sweep
All waveforms can be swept from 0.2Hz to their maximum frequency in a single sweep at a rate
variable between 50 milliseconds and 999 seconds. The sweep is fully phase continuous.
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.
AM
External Amplitude Modulation is available for all waveforms.
FSK and Tone modes
Frequency Shift Keying provides phase coherent switching between two selected frequencies; in
Tone mode the output is stepped asynchronously through a user-defined list of up to 16
frequencies. In both modes the switching source can be the internal trigger generator, front panel,
an external signal or a remote command.
Easy and convenient to use
All of the main generator parameters are clearly displayed together on a backlit LCD with 4 rows
of 20 characters. Sub menus are used to set the parameters for each function.
All parameters can be entered directly from the numeric keypad. Alternatively most parameters
can be incremented or decremented using the rotary encoder.
This system combines quick numeric data entry with quasi-analogue adjustment when required.
Fully programmable via USB and Addressable RS-232 (TG2000 only)
The generator has both USB and RS-232 interfaces which can be used for remote control of all of
the instrument functions.
As well as operating in conventional single instrument mode the RS-232 serial interface can also
be used in addressable mode whereby up to 32 units can be linked to a single PC serial port.
2
Specifications apply at 18°- 28°C after one hour warm-up, at maximum output into 50Ω.
TG1000 limits, where different, are shown in square brackets [ ] after the TG2000 limits.
WAVEFORMS
Standard waveforms of sine, square, triangle, DC, positive pulse and negative pulse.
Sine
Range: 1mHz to 20MHz [10MHz]
Resolution: 1mHz or 6 digits
Accuracy: 10 ppm for 1 year; ± 1mHz below 0.2Hz
Temperature Stability: Typically <1 ppm/ºC outside 18° to 28°C
Output Level:
Harmonic Distortion: <0.3% THD to 20kHz (typically 0.1%)
Non−harmonic Spurii:
Square
Range: 1mHz to 20MHz [10MHz]
Resolution: 1mHz or 6 digits
Symmetry Control: 20% to 80% (1% resolution) 1mHz to 20MHz [10MHz]
Accuracy: 10 ppm for 1 year; ± 1mHz below 0.2Hz
Output Level:
Rise and Fall Times: <22ns
Aberrations: <5% + 2mV
Specifications
2.5mV to 10Vp−p into 50Ω
<–45dBc to 300kHz
<−35dBc to 20MHz [10MHz] (typically <−40dBc)
<–55dBc to 1MHz, <–55dBc + 6dB/octave 1MHz to 20MHz [10MHz]
2.5mV to 10Vp−p into 50Ω
Triangle
Range: 1mHz to 1 MHz
Resolution: 1mHz or 6 digits
Accuracy: 10 ppm for 1 year; ± 1mHz below 0.2Hz
Output Level:
Linearity Error: <0.5% to 100 kHz
Positive and Negative Pulses
Range: 1mHz to 20MHz [10MHz]
Resolution: 1mHz or 6 digits
Symmetry Control: 20% to 80% (1% resolution) 1mHz to 10MHz
Accuracy: 10 ppm for 1 year; ± 1mHz below 0.2Hz
Output Level:
Rise and Fall Times: <22ns
Aberrations: <5% + 2mV
OPERATING MODES
Continuous
Continuous cycles of the selected waveform are output at the programmed frequency.
2.5mV to 10Vp−p into 50Ω
1.25mV to 5Vp-p into 50Ω positive or negative only pulses, with respect
to the DC Offset baseline.
3
Gated
Non-phase coherent gating - output carrier wave is on while Gate signal is high and off while low.
Carrier frequency: From 1mHz to 20MHz [10MHz].
Carrier waveforms: All
Trigger rep. rate: DC to 100 kHz external; to 5kHz using internal trigger generator.
Gate signal source: Manual (front panel MAN TRIG key), external signal (TRIG/GATE IN),
Sweep
Carrier Waveforms: All
Sweep Mode: Linear or logarithmic, single or continuous.
Sweep Width:
Sweep Time: 50ms to 999s (3 digit resolution).
Marker: Available from AUX output. Variable during sweep.
Sweep Trigger Source: The sweep may be free run or triggered from any of the following sources:
External Amplitude Modulation
Carrier Frequency: From 1mHz to 20MHz [10MHz].
Carrier Waveforms: All
Modulation Source: VCA IN socket
Frequency Shift Keying (FSK)
Phase coherent switching between two selected frequencies at a rate defined by the switching
signal source.
Carrier frequency: From 1Hz to 20MHz [10MHz].
Carrier waveforms: All
Switch repetition rate: DC to 5kHz (internal trigger) or DC to 1MHz (external trigger).
Switching signal source: Manual (front panel MAN TRIG key), internal trigger generator, external
Tone
The tone is output while the trigger signal is high and stopped while the trigger signal is low. The
next tone is output when the trigger signal is high again.
Carrier Waveforms: All
Frequency List:
Switching Source: Manual (front panel MAN TRIG key), internal trigger generator, external
Min Switching Time: 1ms per tone
internal gate generator or remote interface.
From 0.2Hz to 20MHz [10MHz] in one range. Phase continuous.
Independent setting of the start and stop frequency.
Manual (front panel MAN TRIG key), external from TRIG/GATE IN or from
remote interface.
signal (TRIG/GATE IN) or remote interface.
Up to 16 frequencies from 1Hz to 20MHz
signal (TRIG/GATE IN) or remote interface.
[10MHz]
OUTPUTS
Main Output
Output Impedance:
Amplitude:
Amplitude Accuracy:
Amplitude Flatness: ±0.2dB to 500kHz; ±2dB to 20MHz [±1dB to 10MHz].
4
50Ω or 600Ω
5mV to 20V pk-pk open circuit, (2.5mV to 10V pk-pk into 50Ω/600Ω).
Output can be specified as HiZ (open circuit value) or V (voltage into
characteristic impedance) in pk-pk, r.m.s. or dBm.
±3% ±1mV at 1kHz into 50Ω/600Ω.
DC Offset Range:
DC Offset Accuracy: typically ±3% ±10mV, unattenuated.
Resolution: 3 digits for both Amplitude and DC Offset.
Pulse Aberrations: <5% + 2mV.
Aux Out
Multifunction output user definable or automatically selected to be any of the following:
Waveform Sync: A square wave at the main waveform frequency. Symmetry is 50% for
Trigger: Outputs a replica of the current trigger signal.
Sweep Sync: Outputs a trigger signal at the start of sweep to synchronize an
Output Signal Level:
INPUTS
Ext Trig /Gate
Frequency Range: DC - 1MHz for FSK; DC – 100kHz for Gate; DC – 2.5kHz for Tone and
Signal Range: Threshold nominally TTL level; maximum input ±10V.
Minimum Pulse Width: 100ns for Gate and FSK modes; 0.2ms for Sweep and Tone modes.
Input Impedance:
VCA In
Frequency Range: DC - 100kHz.
Signal Range: 2.5V for 100% level change at maximum output.
Input Impedance:
INTERFACES (TG2000 only)
RS-232: Variable Baud rate, 19200 Baud maximum. 9-pin D-connector.
USB: Standard USB hardware connection.
GENERAL
Display: 20 character x 4 row alphanumeric LCD.
Data Entry: Keyboard selection of mode, waveform etc.; value entry direct by
Stored Settings: Up to 9 complete instrument set-ups may be stored and recalled from
Size: 260(W) x 88(H) x 235(D)
Weight: 2kg. (4.5lb.)
Power: 110-120V AC or 220V-240V AC ±10%, 50/60Hz,
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.
Safety & EMC: Complies with EN61010-1 & EN61326.
±10V. DC offset plus signal peak limited to ±10V from 50Ω/600Ω.
sine and triangle waves at MAIN OUT; for square waves and pulses
symmetry is the same as that of the waveform at MAIN OUT.
oscilloscope. Can additionally output a sweep marker.
Output impedance 50Ω nominal. Logic levels of <0.8V & >3V, except
for Sweep Sync. Sweep Sync is a 3-level waveform: low at start of
sweep, high for the duration of the last frequency step at end of sweep,
with a narrow 1V pulse at the marker point.
Sweep.
10kΩ
typically 6kΩ.
As well as operating in a conventional RS-232 mode the interface can
be operated in addressable mode whereby up to 32 instruments can be
addressed from one RS-232 port.
numeric keys or by rotary control.
non-volatile memory.
adjustable internally; 35VA max. Installation Category II.
5
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° 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.
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:−
6
l
Caution −refer to the accompanying documentation, incorrect operation may
damage the instrument.
terminal connected to chassis ground.
mains supply OFF.
mains supply ON.
alternating current.
EC Declaration of Conformity
We Thurlby Thandar Instruments Ltd
Glebe Road
Huntingdon
Cambridgeshire PE29 7DR
England
declare that the
TG1000 & TG2000 DDS Function Generators
meet 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 Communities.
EMC
Emissions: a) EN61326-1 (2006) Radiated, Class B
b) EN61326-1 (2006) Conducted, Class B
c) EN61326-1 (2006) Harmonics, referring to EN61000-3-2 (2006)
Immunity: EN61326-1 (2006) Immunity Table 1, referring to:
a) EN61000-4-2 (1995) 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 (2007) Conducted RF
Performance levels achieved are detailed in the user manual.
Safety
EN61010-1 Installation Category II, Pollution Degree 2.
CHRIS WILDING
TECHNICAL DIRECTOR
2 March 2010
7
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 the 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 B
b) Conducted: Class B
c) Harmonics: 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 methods, limits and performance achieved are shown below (requirement shown in
brackets):
a) EN61000-4-2 (1995) Electrostatic Discharge : 4kV air, 4kV contact, Performance A (B).
EMC
b) EN61000-4-3 (2006) Electromagnetic Field:
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 only; signal connections <3m,
e) EN61000-4-5 (2006) Surge, 0·5kV (line to line), 1kV (line to ground), Performance A (B).
f) EN61000-4-6 (2007) Conducted RF, 3V, 80% AM at 1kHz (AC line only; signal
connections <3m, therefore not tested), Performance A (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.’
Cautions
To ensure continued compliance with the EMC directive the following precautions should be
observed:
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: Performance A (A).
25 cycles, 70%: Performance A (C); 250 cycles, 0%: Performance B (C).
therefore not tested), Performance A (B).
8
a) connect the generator to other equipment using only high quality, double−screened cables. For
the purposes of EMC testing it is assumed that signal connections from the instrument will be
<3m and therefore immunity tests for signal lines (Fast Transient and Conducted RF) have
been omitted.
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.
Mains Operating Voltage
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) Unclip the front bezel by gently pulling the centre of each long edge up and forward.
The case halves are held together by 4 plastic push-rivets. Use the blade of a small
screwdriver in the slot beside each rivet to first ease out the rivet head and then fully remove
the rivet body. Separate the case halves. Visit www.tti-test.com
3) Remove the screws securing the pcb to the case lower and lift out the pcb with front and rear
panels attached; lift one side of the pcb at a time, with the case pcb clips on that side pulled
clear of the pcb edge.
4) Change the voltage settings by changing the soldered links beside the transformer:
For 230V operation fit link LK2 only
For 115V operation fit links LK1 and LK3 only
5) Reassemble in the reverse order.
Installation
for further details.
6) To comply with safety standard requirements the operating voltage marked on the rear panel
must be changed to clearly show the new voltage setting.
7) Change the fuse to suit the new operating voltage, see below.
Fuse
Ensure that the correct mains fuse is fitted for the set operating voltage. The correct mains fuse
types are:
The use of makeshift fuses or the short−circuiting of the fuse holder is prohibited.
Mains Lead
Connect the instrument to the AC supply using the mains lead provided. Should a mains plug be
required for a different mains outlet socket, a suitably rated and approved mains lead set should
be used which is fitted with the required wall plug and an IEC60320 C13 connector for the
instrument end. To determine the minimum current rating of the lead-set for the intended AC
supply, refer to the power rating information on the equipment or in the Specification.
Any interruption of the mains earth conductor inside or outside the instrument will make the
instrument dangerous. Intentional interruption is prohibited.
for 230V operation: 250 mA (T) 250V HRC
for 100V or 115V operation: 500 mA (T) 250V HRC
WARNING! THIS INSTRUMENT MUST BE EARTHED.
9
Front Panel Connections
MAIN OUT
This is the output from the main generator; output source impedance can be set to 50Ω or 600Ω.
It will provide up to 20V peak−to−peak e.m.f. which will yield 10V peak-to-peak into a matched
load. To maintain waveform integrity only 50Ω cable should be used and the receiving end should
be terminated with a 50Ω load. It can tolerate a short circuit for 60 seconds.
Do not apply external voltages to these outputs.
AUX OUT
This is a TTL/CMOS level output which may be set to any of the following signals from the
AUX OUT screen.
Connections
waveform sync
Trigger
Sweep sync
AUX OUT logic levels are nominally 0V and 5V from typically 50Ω. AUX OUT will withstand a
short circuit.
Do not apply external voltage to this output.
TRIG/GATE IN
This is the external input for Trigger, Gate and Sweep operations.
Do not apply external voltages exceeding ±10V.
A sync signal phase coincident with the MAIN OUT waveform. For sine
and triangle waves the sync waveform rising edge is at the 0º phase
point of MAIN OUT and the falling edge is at the 180º phase point. For
square waves and pulses both phase and symmetry are coincident with
MAIN OUT.
Provides a replica version of the actual trigger signal; internal, external,
manual and remote all produce a trigger sync.
Goes low at the start of sweep and high at the last frequency step of
the sweep. In addition, a 1/4-amplitude marker pulse can be output at
a specified marker frequency.
VCA IN
10
This is the input socket for external amplitude modulation.
Do not apply external voltages exceeding ±10V.
Rear Panel Connections (TG2000 only)
RS-232
9−pin D−connector compatible with addressable RS-232 use. The pin connections are shown
below:
Pin Name Description
USB
1
−
2 TXD Transmitted data from instrument
3 RXD Received data to instrument
4
−
5 GND Signal ground
6
−
7 RXD2 Secondary received data
8 TXD2 Secondary transmitted data
9 GND Signal ground
No internal Connection
No internal connection
No internal connection
Pin 2, 3 and 5 may be used as a conventional RS-232 interface with XON/XOFF handshaking.
Pins 7, 8 and 9 are additionally used when the instrument is used in addressable RS-232 mode.
Signal grounds are connected to instrument ground. The RS-232 address is set from the
remote menu on the UTILITY screen, see System Operations section.
The USB port accepts a standard USB cable. The Windows plug-and-play functions should
automatically recognise that the instrument has been connected.
11
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. STATUS, AUX OUT; all
soft−key labels, entry fields and messages displayed on the LCD are shown in a different
type−font, e.g
DDS Principles
In this instrument waveforms are generated by Direct Digital Synthesis (DDS). A phase
accumulator is incremented at a rate proportional to the required output frequency. The most
significant 12 bits of the accumulator are used to address a look-up table ROM that converts the
phase information into sinewave amplitude data; this data is then passed to a 10-bit Digital-toAnalogue Converter (DAC) which produces the output waveform. For triangle waves the ROM
look-up table is by-passed and the phase accumulator output is passed directly to the DAC.
At low frequencies all 4096 points in the output wave are stepped through, but as the frequency
increases points are progressively missed out. Sinewaves and triangles are subsequently filtered
to smooth the steps in the DAC output; this technique ensures good sinewave purity up to the
maximum frequency of the generator but the practical limit to which excellent triangle linearity is
maintained is only about 100kHz. Squarewaves and pulses are derived from the sinewave using
a variable threshold comparator; this permits symmetry control of these waveforms across the
whole instrument frequency range.
. WAVEFORM, sine.
General
The major advantages of DDS over conventional analogue generation are:
• Frequency accuracy and stability is that of the crystal oscillator.
• Frequencies can be set with high resolution from mHz to MHz.
• Low phase noise and distortion.
• Very wide frequency sweeps are possible.
• Fast phase continuous frequency switching.
• In addition, being a digital technique, it is easier to make every parameter programmable from
the keyboard, or remotely via the USB or RS-232 interfaces.
Switching On
Switch on the generator using the ON/OFF switch on the rear panel. To fully disconnect from the
AC supply unplug the mains cord from the back of the instrument or switch off at the AC supply
outlet; make sure that the means of disconnection is readily accessible. Disconnect from the AC
supply when not in use.
At power up the generator displays the installed software revision and conducts a self-test.
Power-on self-test takes a few seconds, after which the status screen is displayed, showing the
generator parameters set to their default values, with the MAIN OUT output set off. Refer to the
System Operations 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.
12
Change the basic generator parameters as described in the Standard Waveform Operation
section and switch the output on with the ON key; the lamp above the key 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 MENU key calls the top-level menu from which all functions can be accessed.
Selections are made from this menu using the display soft-keys and numeric values are then
changed using the numeric keys or rotary control, see the Principles of Editing section.
The keys are as follows:
• MENU calls the top-level menu screen from which the main functions can be directly
selected. These are WAVEFORM, FREQUENCY, AMPLITUDE, DC OFFSET, SYMMETRY,
MODE, UTILITY and AUX OUT. Pressing the associated soft-key of any of these functions
calls a further screen which permits the parameters of that function to be edited either from
the numeric keypad or by using the rotary control/cursor keys.
• Numeric/Unit keys permit direct entry of a value for the parameter currently selected. Thus,
having selected the FREQUENCY screen (by pressing the FREQUENCY soft-key on the
MENU screen), a new frequency of 100kHz, for example, is set by pressing 1, 0, 0, kHz.
CE (Clear Entry) undoes a numeric entry digit by digit. ESCAPE returns a setting being
edited to its last value.
• 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 generator’s 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 in the
sections that follow.
Status Display
After the messages at switch-on, or at any time the STATUS key is pressed, the Status display is
shown. With the generator set to the factory defaults (Appendix 2), the display will be:
This display gives an overview of the status of the main generator parameters. If a waveform is
selected for which symmetry can be set (see Specification) the additional field of
shown to the right of the waveform type, see example below:
WAVE:sine
FREQ:10·0000kHz CONT
AMPL:+4·00Vpp
DC:+0·00Vdc (+0·00V)
SYMmetry is
WAVE:square SYM:35%
FREQ:10·0000kHz CONT
AMPL:+4·00V
DC:+0·00Vdc (+0·00V)
For convenience, the WAVEFORM, FREQUENCY, AMPLITUDE, DC OFFSET, SYMMETRY and
MODE screens can be directly selected from the Status display, (i.e. without having to first return
to the main MENU) by pressing the appropriate soft-key beside WAVE, FREQ, AMPL, etc.
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