background image

  

Menus for setting up the range, time (sweep rate), type (continuous, triggered, etc.) spacing 
(lin/log) and marker position are all accessed from this screen using the appropriate soft

key. In 

addition the control screen for manual sweep (i.e. sweeping using the rotary control) is selected 
from this screen and Sweep Mode itself is turned on and off with alternate presses of the  

on 

and

 off 

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 

soft

key returns the display to this

 

SWEEP 

SETUP 

screen.  On all the following menus sweep can be turned on and off with alternate 

presses of the  

on

  

and   

off

  soft-key.  Turning sweep off from this or the following menus 

always returns the mode to continuous. 

Sweep Range 

Pressing the  

range

...

 

soft

key calls the  

SWEEP RANGE

  screen. 

SWEEP RANGE     off

 

 

 

start: 100·00 kHz 

 

stop:  20·000 MHz 

 

centre/span done

 

 

The maximum sweep range for all waveforms is 0.2Hz to 20MHz, except triangle (1MHz). Sweep 
range can be defined by start and stop frequencies or in terms of a centre frequency and span

Start

 

and  

Stop 

soft

keys permit the two end points of the sweep to be set directly from the 

keyboard or by using the rotary control; frequencies can be entered with a resolution of 0.1Hz (or 
5 digits) but in sweep mode the instrument operates with an increment resolution of 0.2Hz and 
the actual frequency of any particular step will be rounded up to the nearest 0.2Hz increment. The 
start frequency must be lower than the stop frequency (but see Sweep Type for selecting sweep 
direction).  
Pressing the  

centre/span

 

soft

key changes the screen to permit entry in terms of

 

centre

 

frequency and sweep  

span 

about that frequency; pressing the  

start/stop

 

soft

key on that 

screen returns the display to the start and stop frequency form of entry. 
Note that when the sweep is displayed in terms of centre frequency and span, the span will be 
shown to the nearest 0.2Hz increment but the centre frequency can be shown to 0.1Hz 
resolution. 

Sweep Time 

Pressing the  

time

...

 

soft

key calls the  

SWEEP TIME

  screen. 

SWEEP TIME      off

 

 

 

      0·05 s 
      

done

 

 

The sweep time can be set from 0·05s to 999s with 3

digit resolution by direct keyboard entry or 

by using the rotary control. The shortest sweep times will have the fewest steps (a 100ms sweep 
will have only 1000 steps whereas a 10s sweep will have 100,000 steps) and will consequently 
have a coarse stepping resolution with very wide sweeps, see Frequency Stepping Resolution 
section for more discussion. 

Sweep Type 

Pressing the

 

type 

soft

key calls the  

SWEEP TYPE

 

screen. 

 

SWEEP TYPE      off

 

 

mode:continuous 

 

 

direction: up 

 

 

sync: on 

done

 

 

  

 

21 

Summary of Contents for tg2000

Page 1: ...THURLBY THANDAR INSTRUMENTS 20MHz DDS FUNCTION GENERATOR TG2000 INSTRUCTION MANUAL...

Page 2: ...utput 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...

Page 3: ...us 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 Amplit...

Page 4: ...digits Symmetry Control 20 to 80 1 resolution 1mHz to 20MHz Accuracy 10 ppm for 1 year 1mHz below 0 2Hz Output Level 2 5mV to 10Vp p into 50 Rise and Fall Times 22ns Aberrations 5 2mV Triangle Range 1...

Page 5: ...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 Carrier wavefor...

Page 6: ...100kHz for Gate DC 2 5kHz for Tone and Sweep 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 Impedan...

Page 7: ...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 liv...

Page 8: ...ropean 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...

Page 9: ...2004 Fast Transient 1kV peak AC line 0 5kV peak signal connections Performance A B 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...

Page 10: ...only 5 Reassemble in the reverse order 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...

Page 11: ...the falling edge is at the 180 phase point For square waves and pulses both phase and symmetry are coincident with MAIN OUT Trigger Provides a replica version of the actual trigger signal internal ext...

Page 12: ...ta 8 TXD2 Secondary transmitted data 9 GND Signal ground 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...

Page 13: ...re derived from the sinewave using a variable threshold comparator this permits symmetry control of these waveforms across the whole instrument frequency range The major advantages of DDS over convent...

Page 14: ...reen 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 aro...

Page 15: ...hanged by further presses of the soft key by pressing either cursor key or by using the rotary control For example pressing the AUX OUT soft key on the main menu brings up the screen shown below AUX O...

Page 16: ...is selected the output waveform is the baseline DC voltage only set from the DC Offset screen Frequency FREQUENCY 10 0000 kHz freq period Pressing the FREQ key gives the FREQUENCY screen With freq se...

Page 17: ...he 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 right arrowed cursor key...

Page 18: ...attenuation provided by the fixed attenuator using the values determined during the calibration procedure In the example displayed the output signal is 250mVpp exactly and takes account of the small e...

Page 19: ...nt sections later in this manual Pressing the AUX OUT key calls the AUX OUT setup screen AUX OUT output on mode auto srce waveform sync AUX OUT is turned on and off by alternate presses of the output...

Page 20: ...shown when an illegal setting is attempted most generally a number outside the range of values permitted In this case the entry is rejected and the parameter setting is left unchanged Examples are 1 E...

Page 21: ...off either by the sweep soft key on the MODE screen accessed from the Main menu by the on and off soft key on the SWEEP SETUP screen accessed by pressing setup on the MODE screen or by the on and off...

Page 22: ...quencies can be entered with a resolution of 0 1Hz or 5 digits but in sweep mode the instrument operates with an increment resolution of 0 2Hz and the actual frequency of any particular step will be r...

Page 23: ...sync set to off the frequency steps directly and phase continuously from the stop frequency to the start frequency but is not synchronised to the software generated trigger signal In triggered mode t...

Page 24: ...rotary control Sweep Spacing Pressing the spacing soft key on the SWEEP SETUP screen calls the SWEEP SPACING screen SWEEP SPACING off logarithmic linear done With linear selected the sweep changes th...

Page 25: ...RANGE screen At the shortest sweep times i e the fewest steps with the widest frequency spans the frequency changes will be quite large at each step if the output is applied to a filter for example th...

Page 26: ...nd from a remote interface With external selected the generator output runs when the signal at the TRIG GATE IN socket is high this input has a TTL level 1 5V threshold The minimum pulse width that ca...

Page 27: ...otary control Tone Gate Source The tone frequency steps changes when the specified trigger signal goes high and continues until the level changes again at which point the output immediately returns to...

Page 28: ...ENCIES screen called by pressing the FSK set up soft key on the MODE screen FSK FREQUENCIES source as gate setup f0 1 000 kHz f1 10 0000 kHz With each frequency selected in turn filled diamond the fre...

Page 29: ...ange 10dB and the full amplitude range is achieved by switching in up to five 10dB attenuation stages Peak modulation cannot exceed the maximum of the range within which the output has been set by cho...

Page 30: ...defaults soft key Note that loading the defaults does not change the set ups stored in memories 1 to 9 or the RS 232 USB interface settings Warnings and Error messages The default setup is for all war...

Page 31: ...etting restore last setup i e the settings at power down are restored at power up or any of the settings stored in non volatile memories 1 to 9 Default values restores the factory default settings see...

Page 32: ...counter to the AUX OUT Frequency meter accuracy will determine the accuracy of the generator s clock setting and should ideally be 1ppm Calibration Procedure The calibration procedure is accessed by...

Page 33: ...sing previous 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 ca...

Page 34: ...hat 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...

Page 35: ...ress for operation on the RS 232 interface is set via the REMOTE menu called using the remote soft key on the UTILITIES screen see System Operations section REMOTE interface RS 232 address 05 baud rat...

Page 36: ...e in the connector at the PC end between pins 1 4 and 6 and between pins 7 and 8 see diagram Pins 7 and 8 of the instrument must not be connected to the PC i e do not use a fully wired 9 way cable Bau...

Page 37: ...hen an instrument 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 commands This allows the i...

Page 38: ...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...

Page 39: ...ons in exactly the same way as a standard port Note that it is necessary to set the virtual COM port to the same Baud rate as the instrument being controlled in exactly the same way as with a standard...

Page 40: ...f those which are specified as addressable RS 232 control codes WHITE SPACE is ignored except in command identifiers e g C LS is not equivalent to CLS The high bit of all characters is ignored The com...

Page 41: ...number nrf thus defining the end of the list TONEFREQ nrf1 nrf2 Set tone frequency number nrf1 to nrf2 Hz FSKFREQ0 nrf Sets FSK frequency 0 to nrf Hz FSKFREQ1 nrf Sets FSK frequency 1 to nrf Hz SWPST...

Page 42: ...the instrument parameters to their default values see DEFAULT INSTRUMENT SETTINGS RCL nrf Recalls the instrument set up contained in store number nrf Valid store numbers are 0 9 Recalling store 0 set...

Page 43: ...ed personnel in conjunction with the service manual which may be purchased directly from the Manufacturers or their agents overseas Cleaning If the instrument requires cleaning use a cloth that is onl...

Page 44: ...rted 10 DC Offset level may cause clipping 12 DC only setting will have no effect 13 DC offset changed by amplitude 15 Symmetry has no effect on this wave 16 Manual sweep mode not selected 24 Instrume...

Page 45: ...aults by the remote command RST Main Parameters Std Wave Sine Frequency 10kHz Output 4 0Vpp Output Off DC Offset 0V Zout HiZ Gate Trigger Parameters Source Internal Period 1ms Sweep Parameters Start F...

Page 46: ...Ltd Glebe Road Huntingdon Cambridgeshire PE29 7DR England Telephone 44 0 1480 412451 Fax 44 0 1480 450409 e mail sales tti test com International website www tti test com UK website www tti co uk Book...

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