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TGP3122
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Aim-TTi TGP3151, TGP3121, TGP3152, TGP3122 User Manual

TGP3151/TGP3121 & TGP3152/TGP3122
Pulse and Universal Generators
1 Table of Contents
1 Table of Contents 1 2 Introduction 4
2.1 The TGP3100 Series of Pulse and Universal Generators ........................................................... 4
2.2 Using this Manual ....................................................................................................................... 5
3 Installation 6 4 Connections 7
4.1 Fr ont Panel Connections ............................................................................................................ 7
4.2 Rear Panel Connections ............................................................................................................. 7
5 Getting Started 9
5.1 I nit ial Operation .......................................................................................................................... 9
5.2 Fr ont Panel Layout ..................................................................................................................... 9
6 Control Principles 12
6.1 Contr ol Menus .......................................................................................................................... 12
6.2 Editing Parameter s ................................................................................................................... 13
7 Output Menu 16
7.1 Setting Output Parameters ....................................................................................................... 16
8.1 Capabilities ............................................................................................................................... 19
8.2 Pulse Funct ions ........................................................................................................................ 19
8.3 S etting Parameters for Pulse .................................................................................................... 20
8.4 S etting Parameters for Square ................................................................................................. 23
8.5 Setting Parameters for Double Pulse ........................................................................................ 23
8.6 Setting Parameters for Pattern/PRBS ....................................................................................... 24
8.7 Pattern Editing .......................................................................................................................... 25
8.8 Pulse Modulation ...................................................................................................................... 27
8.9 Swept Pulse Operation ............................................................................................................. 27
8.10 Pulse Burst Operation (Triggered or Gated) .............................................................................. 27
8.11 Asynchronous Pulse Generation, Delay and Reconstruction .................................................... 27
8.12 Pulse Output Conditions ........................................................................................................... 28
9.1 Capabilities ............................................................................................................................... 29
9.2 S etting Parameters for Noise .................................................................................................... 29
9.3 Noise Modulation ...................................................................................................................... 31
9.4 Noise Burst Operat ion (Triggered or Gated) ............................................................................. 31
9.5 Noise Out put Conditions ........................................................................................................... 31
10.1 Capabilities ............................................................................................................................... 32
10.2 Function and Arbitrary Waveform Menu .................................................................................... 32
10.3 Function Generator Waveforms ................................................................................................ 33
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10.4 Arbitrary Generator Waveforms ................................................................................................ 34
10.5 Waveform Modulation ............................................................................................................... 37
10.6 Sweep Operation ...................................................................................................................... 37
10.7 Burst Operation (Triggered or Gated) ........................................................................................ 37
10.8 ARB/Function Output Conditions .............................................................................................. 37
11.1 Capabilities ............................................................................................................................... 38
11.2 Channel Selection ..................................................................................................................... 38
11.3 Link Menu ................................................................................................................................. 38
12.1 The Modulation Menu ............................................................................................................... 41
12.2 Modulations .............................................................................................................................. 42
13 Sweep Operation 44
13.1 The Sweep Menu ...................................................................................................................... 44
14.2 The Bur st Menu ........................................................................................................................ 47
14.3 Internal Trigger Generator ......................................................................................................... 48
15.2 Trigger Setup ............................................................................................................................ 49
15.3 Sync Output(s) Setup ................................................................................................................ 49
16
Stores Menu 51
16.1 Stores Menu Functions ............................................................................................................. 51
16.2 Instrument Set-ups .................................................................................................................... 51
16.3 Transferring Pulse Patterns and Arbitrary/Noise Waveforms ..................................................... 53
17 Utility Menu 58
17.1 System Settings ........................................................................................................................ 58
17.2 Instrument Settings ................................................................................................................... 59
17.3 I/O (Remote Control) Settings ................................................................................................... 60
17.4 Calibration ................................................................................................................................ 60
17.5 Help .......................................................................................................................................... 60
17.6 Status ....................................................................................................................................... 61
19.1 Waveform Phase and Delay Control ......................................................................................... 64
19.2 Synchronising Two Generators ................................................................................................. 65
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20.1 Address Selection ..................................................................................................................... 67
20.2 Remote/Local Operation ........................................................................................................... 67
20.3 USB Interface ........................................................................................................................... 68
20.4 LAN Interface ........................................................................................................................... 68
20.5 GPIB Interface .......................................................................................................................... 70
20.6 Status Reporting ....................................................................................................................... 71
21 Remote Commands 74
21.1 Command List .......................................................................................................................... 74
23.1 Waveforms ............................................................................................................................... 86
23.2 Standard Waveforms ................................................................................................................ 86
23.3 Modulation ................................................................................................................................ 90
23.4 Gated Burst .............................................................................................................................. 92
23.5 Triggered Burst ......................................................................................................................... 92
23.6 Sweep ...................................................................................................................................... 92
23.7 Dual-channel Operations (applies only to TGP31x2) ................................................................ 93
23.8 Outputs ..................................................................................................................................... 94
23.9 Inputs ....................................................................................................................................... 95
23.10 Interfaces .............................................................................................................................. 96
23.11 General ................................................................................................................................. 96
24.1 General..................................................................................................................................... 97
24.2 Waveform Manager Plus .......................................................................................................... 97
27.1 Equipment Required ............................................................................................................... 108
27.2 Calibration Procedure ............................................................................................................. 108
27.3 Calibration Routine ................................................................................................................. 109
27.4 Remote Calibration ................................................................................................................. 110
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2 Introduction

2.1 The TGP3100 Series of Pulse and Universal Generators

General Description 2.1.1

The TGP3100 Series are true pulse generators using all digital techniques. They can replicate the capabilities of traditional pulse generators whilst adding many additional facilities such as pulse modulations.
Unlike DDS based function generators the TGP3100 Series can generate pulses with very high resolution of width and delay (100ps), and can operate in an asynchronously triggered mode with low jitter.
A high drive capability output stage enables up to 20 volts pk-pk to be driven into a 50 Ohm load. As well as operating as pulse generators, the instruments can act as high performance noise generators
and as function/arbitrary generators - making them truly universal waveform generators. Single and dual channel models are available with a maximum frequency of either 50MHz or 25MHz

Important Features 2.1.2

Pulse waveforms from 1mHz to 50MHz [25MHz], minimum rise time 5ns [8ns] Pulse, double pulse, pulse pattern and PRBS waveforms Pulse period, width and delay resolutions of 100ps or 11 digits Independently variable rise and fall times from 5ns [8ns] to 800 seconds Low jitter asynchronous operation, externally triggered pulses or pulse reconstruction High drive capability output can provide 20V pk-pk into 50Ω (unmatched) Wide range of pulse modulations including AM.FM, PM, FSK, BPSK, SUM, PWM, PDM
using internal or external modulation sources. Triggered (burst count) or gated operation using internal or external trigger sources Full Noise generator to 25MHz [12.5MHz] with selectable crest factor and user defined distribution Full Arbitrary/Function generator with 16 waveform types Sine waves up to 50MHz [25MHz] Arbitrary waveforms at 800MS/s sampling rate and 16-bit vertical resolution Extensive internal/external modulation of all waveform types Linear and logarithmic sweeps of all waveform types Front panel mounted USB Flash drive interface GPIB, USB and LXI compliant LAN interfaces
4

2.2 Using this Manual

This manual is for the TGP3151 and TGP3121 single channel generators and the TGP3152 and TGP3122 dual channel generators. Wherever there are differences in the specification, the limits for the TGP312x are shown in square brackets [ ] after the TGP315x limits.
In this manual front panel keys and sockets are shown in capitals, e.g. SWEEP, SYNC OUT. Soft−key labels on the LCD are shown in a different type−font, e.g.
The manual is available in printed form and as an electronic document in PDF format. The manual includes cross references which are underlined within the text. These are hyperlinks within the PDF document. The Table of Contents is also fully hyperlinked.
Hyperlinks enable the user to jump rapidly to the section referred to and then jump back to continue reading the original section. (N.B. for hyperlink navigation within Acrobat Reader, enable “show all page navigation tools” or use the keyboard shortcuts Alt+Left_Arrow and Alt+Right_Arrow).
Width, Offset.
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3 Installation

Mains Operating Voltage 3.1.1

This instrument has a universal input range and will operate from a nominal 115V or 230V AC supply without adjustment. Check that the local supply meets the AC input requirement given in the Specification.

Mains Lead 3.1.2

Connect the instrument to the AC supply using the mains lead provided. Should a power plug be required for a different power 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.
WARNING! THIS INSTRUMENT MUST BE EARTHED. Any interruption of the power earth conductor inside or outside the instrument will make the instrument
dangerous. Intentional interruption is prohibited.

Mounting 3.1.3

This instrument is suitable both for bench use and rack mounting. It is delivered with soft protective front and rear bezels which have integral moulded feet; this is the most suitable configuration for bench use.
For rack mounting the protective bezels and handle/stand can be removed such that the instrument can be fitted beside any other standard 2U half-rack instrument in a 19” rack. A suitable 2U 19” rack kit is available from the Manufacturers or their overseas agents; full details of how to remove the handle and bezels are included with the kit.

Ventilation 3.1.4

The generator uses a small fan fitted to the rear panel. Take care not to restrict the rear air exit or the inlet vents at the front (sides and underneath). In rack-mounted situations allow adequate space around the instrument and/or use a fan tray for forced cooling.

Handle/stand 3.1.5

The instrument is fitted with a 4-position handle/stand. Pull out both sides of the handle at the case pivot points, to free the position locking pegs, and rotate the handle from the stowed position to the required stand or handle position. Release the sides of the handle to lock it in the new position.
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4 Connections

4.1 Front Panel Connec tions

MAIN OUT (one for each channel on dual channel instruments) 4.1.1
This is the variable amplitude output from main generator. It can provide up to 22V peak−to−peak e.m.f. from a 5 0Ω or 5Ω source impedance. The output has both over-voltage and over-current protection and will turn off in the event of an output short circuit.
See section 7 Output Menu
Do not apply an external voltage to this output.
SYNC OUT (one for each channel, rear mounted on dual channel instruments) 4.1.2
Logic level output which can generate a synchronisation signal related to the main (carrier) waveform, modulation waveform, trigger or gate signal, or sweep marker.
See section 15 Trigger and Sync Menu
Do not apply an external voltage to this output.

FLASH DRIVE 4.1.3

This is a USB Host port for the connection of most types of flash drive which conform to the Mass Storage Class specification. The instrument will accept drives formatted with the FAT16 or FAT32 filing systems. This port does not support any other class of device.
for more details.
for more details.

4.2 Rear Panel Connections

SYNC OUT (Rear mounted on TGP31x2 only. One for each channel) 4.2.1
See Front Panel section for description.

MOD IN 4.2.2

This is the external modulation input socket for AM, FM, PM, SUM, BPSK PWM, PDM, SPDM, or external pattern. Full-scale input is ±2.5V, frequency DC to 5MHz.
Do not apply an external voltage exceeding ±5V.

10MHz REF IN 4.2.3

Input for an external 10MHz reference clock. Input range 1Vpp – 5Vpp.
Do not apply external voltages exceeding + 5V or –1V to this signal connection.

10MHz REF OUT 4.2.4

Buffered version of the 10MHz clock currently in use (internal or external). Output level nominally 3V logic from 50Ω.
Do not apply external voltages to this output.

TRIG IN 4.2.5

This is the external input for Trigger, Gate and Sweep operations. It is also the input used to synchronise the generator (as a slave) to another (which is the master).
Do not apply an external voltage exceeding ±10V.
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LAN (Ethernet) 4.2.6

The LAN interface is designed to meet 1.4 LXI (Lan eXtensions for Instrumentation) Core 2011. Remote control using the LAN interface is possible using the TCP/IP Socket protocol. The instrument also contains a basic Web server which provides information on the unit and allows it to be configured.
Further details are given in section 20 Remote Interface Operation
.

USB 4.2.7

The USB port is connected to instrument ground. It accepts a standard USB cable. If the USB driver has been installed from the CD, the Windows plug-and-play function should automatically recognise that the instrument has been connected. See the USB folder on the CD for information on installing the driver on a PC.
Further details are given in section 20 Remote Interface Operation
.
GPIB (IEEE−488) 4.2.8
The GPIB interface 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 default GPIB address is 5. Further details are given in section 20 Remote Interface Operation
.
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5 Getting Started

5.1 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 of this manual.

Switching On 5.1.1

The power switch is located at the bottom left of the front 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 a start-up message whilst initialising the application. Loading takes a few seconds, after which the pulse waveform set-up screen is displayed, showing the generator parameters set to their default values, with the MAIN OUT output(s) set off.
This is the Factory Defaults state which will appear whenever the instrument is powered on.. Alternatively the instrument can be set so that it returns to its settings at power down. See section 17.1.1 Power-On Settings down (latest settings) or to the defaults.
In the event that an error is encountered while the instrument is initialising, an error message will be displayed, see the Warnings and Error Messages section for an explanation.
for how to change the power up settings to either those at power

5.2 Front Panel Layout

The front panel contains the liquid crystal display (LCD) and the keyboard which are used together to control all instrument functions.
(Dual channel instrument shown, single channel instrument differs only around output sockets)

Keyboard 5.2.1

The keys are grouped as follows: Six soft-keys under the display. The function of these keys change as the instrument is operated. The
current function is shown on the LCD soft-key label above each key. An empty label means that the key currently has no function.
Numeric keys permit direct entry of a value for the parameter currently selected. Six keys under the soft-keys select the carrier waveform from PULSE, SQUARE, DOUBLE PULSE,
P A TTERN/PRBS and ARB/FUNCTION. The key representing the currently selected waveform glows green. Pressing another waveform key
brings up the parameter screen for the new waveform but does not change the waveform until the
Apply key is pressed.
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Parameters Box
Status Line
Soft
Status Line Dual channel
Three keys to select the waveform modification mode from MOD (modulation), SWEEP and BURST. The selected key glows yellow. If all keys are unlit the mode will be continuous carrier wave.
The OUTPUT key(s) open the Output Settings menu which allows the parameters for the selected channel to be edited. On a dual channel instrument the keys also select the current channel as displayed on the left hand side of the status line. Note that the OUTPUT key(s) do not turn the outputs on or off directly, this is done via a soft-key in the Output Menu screen.
TRIGGER/LOCAL key. Used to enter the Trigger menu where the instrument trigger parameters may be specified. This key is also used on a dual channel instrument to return to local from remote mode.
UTILITY key gives access to menus for a variety of functions such as SYNC OUT set−up, power−up parameters and error message settings.
STORES key allows access to the built in storage for waveforms and set-ups and to a connected flash drive.
SPIN WHEEL and left and right cursor keys. Used during numeric entry. The left and right keys move the edit position left or right and the spin wheel increments or decrements the value of the selected digit.
The HELP/ LOCAL key, available on a single channel instrument, gives direct access to the complete help system. On a dual channel instrument the help system is accessed from the Utility menu. However, context sensitive help can be obtained for any key, including soft-keys, by holding the key down for 2 seconds. The HELP/ LOCAL key is also used on a single channel instrument to return to local from remote mode.
Further explanations will be found in the detailed descriptions of the generator’s operation.

Display 5.2.2

All parameter settings are displayed on the backlit liquid crystal display (LCD). The most common type of display layout is shown below:
The Status Line indicates the status of the instrument as follows(from left to right): The Channel field is blank on a single channel instrument. On a dual channel instrument it indicates
which channel is currently selected for editing ( change to
Track . If the channels are Tr ack ing with inversion the field will show InvTk .
CH1 or CH2). If the channels are Tracking the field will
Graph Box
Edit Box
-key
The Waveform field shows the currently selected pulse mode, waveform or pattern (e.g. PULSE).
The Output signal status for the channel is displayed as
On or Off.
The selected load impedance is shown in Ohms. If the output is set to be inverted
Inv will be displayed
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The next field indicates the external clock status. If the internal clock is being used, nothing is displayed. If an external clock is being applied or is being used, the symbol appears. If the clock is in use
the symbol is followed by an arrow. If a valid clock signal is detected (but not used), the symbol is followed by
the symbol is followed by
DET . If the clock source is set to external and a valid external clock signal is not detected,
ERR .
When the instrument is under remote control via any interface The field indicates the status of the Local Area Network interface. As shown, there is no LAN
connection. When connected the field will change to . While a connection is being established the indicator will flash. If the LAN is connected but not enabled the field will show as . See section 20 Remote Interface Operation
The Parameters Box on the left shows the waveform parameter settings for the selected channel. These always include shown will depend upon the waveform type. When a waveform modifier (Modulation, Sweep or Burst) is enabled, the right hand section will show parameters of the modifier.
The Graph Box on the right shows a representation of the waveform which the instrument is generating on the selected channel. The parameter currently being edited is indicated by arrows.
The lower part of the display contains the Edit Box which shows the value of the parameter currently being edited on the selected channel. This will be a numeric value or a parameter string.
Under the Edit Box are the current Soft-key Labels which change as editing proceeds. The Status Line and the Soft-key Labels are always shown on the LCD. The section between these
areas will sometimes change in appearance, for example when displaying help. A Pop-up Box may also appear to provide error or warning messages or to give other information to the
user. See Appendix 1. Information, Warning and Error Messages
FRQ (frequency), AMP (amplitude) and OFS (offset). Additional parameters
for more detailed information.
REM will be displayed.
for a full list of messages.
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6 Control Principles

6.1 Control Menus

Menus are selected using the keys shown below:

Main Menus 6.1.1

There are four types of Main Menu: Waveform Menus (Pulse, Square, Double Pulse, Pattern/PRBS, Noise, ARB/Function)
These are selected using the six illuminated keys below the display. Parameters can be set for any waveform without making that waveform active. Separate waveform parameters are retained for each.
Modification Menus (Modulation, Sweep, Burst) These are selected using the three illuminated keys to the bottom right of the display. The three waveform modification modes are mutually exclusive.
Output Menu(s) This is selected using the illuminated Output key(s). On dual channel instruments this is also used to change the channel for subsequent editing.
Link Menu (dual channel instruments only) This is selected with the Link key between the two output keys. It enables coupled or tracking operation of the two channels to be set up.
Note that a menu is re-selected by pressing the appropriate menu key again. For example, having set up Burst parameters for a Pulse waveform, press the Pulse key to close the Burst menu and return to the Pulse menu.
Sub Menus
Each main menu may have a number of sub menus which are selected using the soft-keys. These sub menus will include a key marked
Done and may contain a key marked .
The key is known as BACK and will move up one level in the menu hierarchy. The move directly to the top level in the hierarchy.
Additional options within any menu are accessed using the key.
Done key will
Channel Selection (dual channel instruments only) 6.1.2
On a dual channel instrument, the OUTPUT 1 and OUTPUT 2 keys are used to change the channel currently being edited. For example if Channel 1 is being edited, and a change is required to the main waveform parameters of Channel 2, press the OUTPUT 2 key, f ollowed by the currently selected Waveform key.
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Additional Menus 6.1.3

Four additional menus are available: Stores
Provides access to internal or external storage of Set-ups, Arbitrar y Waveforms, Noise Distribution or Patterns.
Utility
Provides access to system settings, instrument operational settings, interface settings, and calibrations.
Trigger
Provides access to the set-up for the external trigger input and Note that the TRIGGER menu key can also act as the manual trigger.
Help
Offers explanation for specific topics of the instrument’s operation. Note that context sensitive help is also available from holding down the relevant key. Note that, on dual channel instruments there is no HELP key and the Help menu is selected from within the Utility menu.
the set-up for the Sync output signal(s).

6.2 Editing Parame ter s

The instrument parameters are edited using the keyboard in conjunction with the Soft-key Labels and the Edit Box.
Soft-key Types 6.2.1
Within any menu, the parameter to be edited is selected with a soft-key. There are three types of soft­keys:
Numeric parameter keys (single function) These keys select a single numeric parameter for editing. When pressed, the key changes to white text on a black background and the current value of the parameter appears in the edit box.
Numeric parameter keys (multiple function) These keys have more than one function that changes with multiple presses of the key. W hen first pressed the key changes to white text on a black background with a small arrow on the right hand side. Subsequent presses change the soft-key text between two or more parameter options (e.g. Frequency or Period).
13
Option selection keys (single option) These keys select a single option of a parameter. An example is the waveform selection keys within the Wave sub-menu of the Arb/Function waveform menu.
These keys do not change background colour when pressed and remain as black text on a white
background. Option selection keys (multiple options) These keys select between multiple options of a parameter.. When first pressed the key changes to white text on a black background with a small arrow on the right hand side. The current option appears in the Edit Box.
Subsequent presses change the option as shown in the edit box (e.g. Coupled or Independent).

Numeric Editing 6.2.2

Any numeric parameter may be changed in one of the following ways:
Enter a new value from the numeric key pad.
Use the left and right cursor keys to select a digit position then use the spin wheel to
increment/decrement the value at that position.
Examples of each method are shown below.

Using the Numeric Key Pad 6.2.3

Pressing a number key will erase the current parameter value in the Edit Box and replace it with the
current entry. The Soft-key Labels will also change to a list of units applicable to the parameter being
edited. The examples below show frequency units and period (time) units respectively.
During the numeric data entry a decimal point and, if appropriate, a sign may be entered. The
is used to alternately change the sign between + and –. The left cursor key may be used to erase the
last digit entered. The entry may be cancelled by pressing the
Once the entry is complete it may be terminated by pressing the soft-key below the required units. The
value will be checked and accepted as the new value for the relevant parameter.
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Cancel key
+/- key

Using the Spin wheel and Cursor Keys 6.2.4

A numeric parameter will be displayed with an inverse edit cursor over one of the digits. The left and right cursor keys may be used to move the edit cursor to any digit in the value. Values are always shown with enough digits to the right of the decimal point to show the best resolution for the parameter. For example the right-most digit in a frequency value will be mHz.
Depending on the actual value one or more digits to the left of the most significant digit displayed may be zero and will not be shown. It is possible to move the edit cursor into these digit positions and the suppressed zeros will be shown as in the example below.
With the edit cursor positioned at the required digit the spin wheel may be rotated left or right to decrement or increment the digit. As the value passes between 9 and 0 the digits to the left will also change. In this way it is possible to set any legal value for the parameter.
Changes made by turning the spin wheel are applied immediately to the parameter as long as the value remains legal.
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7 Output Menu

7.1 Setting Output Parameters

The output menu sets the output condition for each channel independently of the waveform type.
It is selected by pressing the OUTPUT key (single channel instruments) or the OUTPUT1 or OUTPUT2
key (dual channel instruments).
Note that, on a dual channel instrument the OUTPUT keys are also used to select the channel for
editing.
To return from the output menu to a waveform menu or other menu, press the appropriate menu key.

Output On/Off 7.1.1

Pressing the On/Off soft-key toggles the output On or Off. The OUTPUT key is illuminated when the
output is On.

Output Amplitude and Offset (High and Low Levels) 7.1.2

The output can be set either in terms of a peak to peak amplitude and a DC offset, or as a high level and
a low level. Multiple presses of these soft-keys toggles between these two modes with the key names
changing accordingly (
Pressing either soft-key displays the parameter in the Edit Box and the Graph Box changes to show the
parameter that is being edited.
Ampl <> HiLvl and Offset <> LoLvl).
The maximum and minimum voltage levels depend upon the source and load impedances. The
maximum and minimum EMF amplitudes (high impedance load) are 22V pk-pk and 200mV pk-pk
respectively. The maximum and minimum high and low EMF levels are +11V and -11V.
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Output Phase 7.1.3

Pressing the Phase soft-key creates a set of further soft-keys from which the output phase can be adjusted.
Phase
The output phase defines the position of the output waveform relative to the synchronisation signal. It can be set between 0 and 360 degrees to a resolution of 0.001 degrees.
For continuous waveforms, the phase relates to the carrier sync signal. For triggered waveforms the phase relates to the trigger signal. Either signal is available at the SYNC output socket.
Pressing the the phase graphically .
Reset
Pressing the
Align
In a 2 channel generator, or a generator phase locked to another generator, changes to frequency or other parameters can cause a loss of phase alignment.
Pressing the
Phase soft-key displays the phase in the Edit Box and the Graph Box changes to show
Reset soft-key returns the phase to zero (0.0 degrees).
Align soft-key realigns the phase between the channels or generators.

Output Polarity 7.1.4

Pressing the voltage levels become negative and vice versa.
Polarity soft-key alternates between Normal and Inverted. When inverted, positive

Output Range (Glitch Free Level Changing) 7.1.5

In order to achieve a wide output voltage range whilst retaining high vertical resolution, the output circuitry incorporates multiple attenuators. When a new level is set, the attenuators are automatically selected to gives the highest possible vertical resolution.
A consequence of changing the attenuator settings is small glitches on the output while this takes place. Some applications require glitch-free changes in level. To achieve this the attenuator position needs to be fixed based upon the highest level required (amplitude plus offset), with lower levels achieved only through attenuation via the DAC.
Successive presses of the
Range soft-key alternate between Range: Auto and Range: Hold.
17

Output Source Impedance 7.1.6

Pressing the Source soft-key toggles the output impedance between 50 Ohms and 5 Ohms.
When dr iving a 50Ω load from 50Ω source impedance the maximum EMF of 22V pk-pk is reduced to
11V pk-pk. By changing the source impedance to 5Ω, the voltage into a 50Ω load can be increased to
20V pk-pk.
Note that, depending upon cable length and edge speeds, the impedance mismatch will degrade the
pulse shape.
WARNING
When the source impedance is set to 5Ω a short circuit, or very low load impedance, may cause the
over-current trip to operate turning the output off. It is advisable to make connection to the load with the
output set to off.

Load Impedance 7.1.7

Pressing the Load soft-key enables the intended load impedance to be set. The displayed output
amplitudes are calculated based upon the source and load impedances.
Successive presses of the
impedance). The numeric value can be set between 50Ω and 10kΩ.
Load soft-key toggles between a numeric value and High-Z (high
18
8 Pulse Generator Operation

8.1 Capabilities

The instrument can produce a wide range of pulses with adjustable period, width, delay and edge speed. It may also be set in Gated or Triggered mode, Swept Frequency mode, or be modulated using a wide variety of internal or external modulators. For more information see the sections on Burst, Sweep and Modulation.
Each channel of a two channel instrument has an independent pulse generator. These may be set to any combination of period, width, delay and modulation or burst. However, when the channels are linked by one of the dual-channel functions there are some restrictions between the parameters of the two channels; see the Dual-Channel Operations section of the Specification for details.

8.2 Pulse Functions

When operating as a pulse generator, the instrument has four functional types of operation as selected by the illuminated keys below the display - Pulse, Square, Double Pulse and Pattern/PRBS.

Changing Functions 8.2.1

The function is selected by pressing one of the illuminated keys below the display. However, the function is not changed until the
new function to be reviewed or altered prior to the change of function.
Apply soft-key is pressed. This allows the parameters of the
The function key for the currently active function will remain illuminated and the key for the new function will flash until the
key will perform the Apply function.
Apply key is pressed. Alternatively a second press of the flashing

Pulse 8.2.2

This function provides the maximum flexibility as to how pulses are defined. The pulse period (i.e. how often free running pulses are repeated) can be set as a repetition rate
(Freq.) or as a time (Period). The pulse width can be set as an absolute time (Width) or as a percentage of the repetition
period (Duty). The rise and fall times can be set independently or together (Edge) and the delay time from the
trigger/sync point set as an absolute time (Delay) or a percentage of the period (Delay%).

Square 8.2.3

This is a simplified version of the Pulse function in which rise and fall times are always minimum, and the pulse always commences at the start of the period (delay = zero).
The pulse width is always defined by duty cycle percentage (DtyCyc) and has a default value of 50%.

Double Pulse 8.2.4

This is an extended version of Pulse function in which two identical pulses are generated during each period.
The delay between the two pulse can be set as an absolute time (DblDel) or a percentage of the period (DblDl%). The delay is defined as from the start of pulse one to the start of pulse two, and therefore includes the width and edge times of one pulse.

Pattern/PRBS 8.2.5

This enables patterns of pulses to be produced either from user defin ed patterns or fr om a PRBS (Pseudo-Random Bit Sequence) algorithm. Patterns can be defined externally with the generator acting as a pulse reconstruction engine.
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Retained Settings 8.2.6

The instrument retains independent settings for the four pulse functions.

Invalid Settings 8.2.7

In order for the settings to be valid, they must conform to rules which ensure that the period is equal to or greater than pulse width plus delay plus 0.625 x (rise plus fall times) plus 3.75ns.
The minimum period is 20ns [40ns], minimum pulse width 10ns [20ns], minimum delay 0ns, minimum rise/fall times 5ns each [8ns]. For Double Pulse mode, the double pulse delay must be added (minimum 20ns).
Attempting to make an invalid setting will bring up an error message on the display. No change to settings will be made.

Changing Channels (dual channel models only) 8.2.8

The current channel being edited is shown at the top left of the display (CH1 or CH2). Pressing either of the two keys marked OUTPUT 1 or OUTPUT 2 opens the Output Menu for Channel 1 or Channel 2, and sets the current editing channel accordingly.
Thus, to move from editing waveform parameters CH1 to editing CH2, press the OUTPUT 2 key followed by the appropriate waveform key below the display. Illumination of the OUTPUT 1 and OUTPUT 2 keys indicates that the output is turned On.

8.3 Setting Parame ter s for Pulse

Frequency/Period 8.3.1

The frequency or period may be changed in either of the ways detailed in section 6.2.2 Numeric Editing.
Pressing the Freq soft-key while it is highlighted will change the label to Period and vice versa.
The parameter units will change between frequency and time as appropriate. Note that the upper
frequency limits are lower for the TGP312x than for the TGP315x.

Pulse Width 8.3.2

Pressing the Width soft-key opens the Width Sub-menu, along with the width parameter in the Edit
Box The Graph Box changes to show that width is being edited. The value of the Width may be
changed as detailed in section 6.2.2 Numeric Editing
be set in any of three different ways
. The sub-menu enables the width of the pulse to
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Width
Pressing the time from the mid point of the rising edge to the mid-point of the falling edge.
Duty Cyc le
Pressing
0.01%.
Width shows the width of the pulse in terms of time (ns, us, ms or s). The value represents
Duty shows the width of the pulse as a percentage of the period to a maximum resolution of
Fall Delay
Pressing represents the time from the mid point of the rising edge to the start of the falling edge.
Fall Del shows the width of the pulse in terms of time (ns, us, ms or s). The value
21

Pulse Delay 8.3.3

Pressing the Delay soft-key shows the delay parameter in the Edit Box and the Graph Box changes
to show that delay is being edited.
The Graph box shows the delay parameter between the arrows.
Delay can be specified in terms of time (ns, us, ms or s), or as a percentage of the period. Pressing the
key alternates between
Delay and Del%.
Changing the delay causes the start of the pulse to be delayed with respect to the sync pulse available
at the SYNC OUT connector.
The delay also adds a delay between the trigger signal and the pulse output during burst modes. See
section 14 Burst Operation
relative timings of the pulses in dual channel modes.
for more details of Burst and Gate modes. The delay also changes the

Edge Time 8.3.4

Pressing the Edge soft-key opens the Edge sub-menu. The edge time represents the time between
the 10% and 90% points on the pulse edges. Rise time and fall time can be adjusted independently or
together (Coupled).
The
Mode soft-key toggles between Independent or Coupled mode. For Independent mode, two soft-
keys (
Rise and Fall ) are provided. For Coupled mode there is a single soft-key of Edge.
22
Alternatively the edge time can be entered as a percentage of the pulse width.
The selected edge time may be changed in either of the ways detailed in 6.2.2 Numeric Editing
.

8.4 Setting Parame ter s for Square

General 8.4.1

Square is a simplified version of Pulse in which the edge speed is always maximum, and the delay is always zero. The on time is always specified in terms of duty cycle.

Frequency/Period 8.4.2

The frequency or period may be changed in either of the ways detailed in section 6.2.2 Numeric Editing. Pressing the Freq soft-key while it is highlighted will change the label to Period and vice versa.
The parameter units will change between frequency and time as appropriate. Note that the upper frequency limits are lower for the TGP312x than for the TGP315x.

8.5 Setting Parame ter s for Double Pulse

General 8.5.1

The Double Pulse function generates two identical pulses with a selectable delay between them. Setting up of Double Pulse is identical to setting Pulse parameters (as described earlier), but with the
additional parameter of delay between the pulses.

Double Pulse Delay 8.5.2

This parameter specifies the delay between the start of the first pulse and the start of the second pulse.
Pressing the changes to show that delay is being edited.
DblDel soft-key shows the delay parameter in the Edit Box and the Graph Box
Alternatively the delay can be set in terms of a percentage of the period.
23

8.6 Setting Parame ter s for Pattern/PRBS

General 8.6.1

Patterns of pulses can be produced either from user defined patterns or from a PRBS (Pseudo-Random
Bit Sequence) algorithm. Bit rates from 1mbps up to 50Mbps [25Mbps] can be used and internally
stored patterns can have up to 65536 bits. PRBS sequence lengths are between 127 to 8,388,607 bits.
Patterns can also be defined externally with the generator acting as a pulse reconstruction engine.
Bit Rate 8.6.2
The bit rate is set in terms of bps (bits per second) in a similar way to setting frequency. The pattern repetition rate is a function of the bit rate and the pattern length.
Pressing the be changed as detailed in section 6.2.2 Numeric Editing.

BitRate soft-k ey shows the bit rate parameter in the Edit Box and the value can

Edge Time 8.6.3

The pulse edge transition time is variable in a similar way to other pulse modes; however, the rise and fall times are always set equal.
Pressing the changes to show that edge time is being edited.
Edge soft-key shows the edge time parameter in the Edit Box and the Graph Box

Pattern Source 8.6.4

Pressing the Source soft-key creates a set of furt her soft-keys from which the source of the pulse pattern can be selected.
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Internal Patterns
The soft-keys Each pattern can have up to 65536 bits and can be loaded from a flash drive or from the digital
interfaces. Patterns can be created externally or created/edited internally, see section 8.7 Pattern Editing
Pttn1 through Pttn4 select one of four patterns stored within the instrument.
.
External Patterns
Patterns can be generated externally whereby the generator acts as a pulse shaper and amplifier. Two methods are available.
Pressing the the external pattern source. In this mode external patterns at up to 5Mbps can be applied and
these are synchronised to the generator's internal clock using a 50Mbps sampling clock. Pressing the
the external pattern source. In this mode external patterns at up to 50Mbps can be applied which are regenerated at the output asynchronously relative to the generator's system clock. This enables the generator to act as a low jitter asynchronous pulse shaper and amplifier.
PRBS
Pressing the Random Bit Sequence).
Pressing the extra soft-key of
Pressing the selected from eight different types.
ModIn soft-key selects the modulation input (MOD IN socket on the rear panel) as
TrigIn soft-key selects the trigger input (TRIG IN socket on the rear panel) as
PRBS soft-key selects the source as an internally generated PRBS (Pseudo-
Done soft-key returns to the main Pattern/PRBS menu which will then include an
Type .
Type soft-key creates a set of further soft-keys from which the PRBS type can be
For information about PRBS types see Specifications section 22.2.4 Pattern/PRBS

8.7 Pattern Editing

Patterns can be created or edited externally to the instrument using the Aim-TTi Windows application Waveform Manager Plus (v4.1 or later). These can be transferred using a USB Flash drive or loaded via the digital interfaces.
Alternatively patterns can be created and edited within the instrument. Pressing the soft-key from the Pattern/PRBS main menu opens the Pattern Edit Select sub-menu
The soft-keys Each pattern can have up to 65536 bits and can be loaded from a flash drive or from the digital
interfaces.
The soft-keys soft-key creates the Pattern Edit menu.
Pttn1 through Pttn4 select one of four patterns stored within the instrument.
Pttn1 through Pttn4 select one of the four patterns and pressing the Edit
.
EditPttn
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Each pattern has a default name of PATTERN1 thro PATTERN4 and has a default length of 4 bits
arranged as Low, High, Low, Hig h.

Pattern Length 8.7.1

Pressing the Length soft-key enables the length of the pattern to be defined. Additional bits created are always as alternating high/low states. Minimum pattern length is 1 bit and maximum
is 65536 bits.

Pattern Preamble 8.7.2

When the pattern is used as a triggered burst (where the pattern is replayed more than once in response to a trigger signal), it is possible to define a section at the start of the pattern which is only replayed once. This is called the preamble.
Pressing the Preamb soft-key enables the length of the preamble section to be defined. Note that the preamble remains part of the pattern length.

Setting Point Levels 8.7.3

Pressing the Point soft-key creates an additional set of soft-keys from which the level of each point in the pattern can be set.
The
Point# soft-key allows the point number to be selected and its current level shown within
the edit box. The level for each point can be changed by pressing the
High or Low soft-keys.

Pattern Renaming 8.7.4

Pressing the Name soft-key creates a further sub-menu from which the name can be changed.
A name of up to 8 characters can be used. The cursor keys < > are used to select the character and the spin wheel used to change the character. When the wheel is turned clockwise the characters change in the following order: 0 to 9, A to Z , ^ _ ' { } ~ (space) ! # $ % & ' ( ) -
26
Spaces can be introduced or characters deleted using the changed when the
Execute soft-key is pressed.
Space soft-key. The name is

Pattern Reset 8.7.5

Pressing the Reset soft-key opens a further sub-menu from which the pattern can be reset to either Default (alternating Highs and Lows) or All Highs or All Lows. The pattern length is not
changed.

8.8 Pulse Modulation

All pulse types can be modulated in a wide variety of ways using an internal or external source. See section 12 Waveform Modulation
Note that FM modulation of pulses will retain a fixed pulse width even when the width has been set as a duty cycle percentage.
.

8.9 Swept Pulse Opera tion

All pulse types can have their frequency swept over a wide range at a variable rate. See section 13 Sweep Operation
Note that swept pulses will retain a fixed pulse width even when the width has been set as a duty cycle percentage.
.

8.10 Pulse Burst Operation (Triggered or Gated)

All pulse types can be triggered or gated. See section 14 Burst Operation.

8.11 As ynchronous Pulse Generation, Delay and Reconstruction

Conventional digital waveform generators align all waveform points to a system clock. In consequence, pulses generated in response to an asynchronous external trigger signal will be subject to jitter.
TGP3100 Series generators incorporate circuitry that measures the interval between the external trigger event and the system clock, and adds a compensating amount of time so as to provide a fixed delay between trigger and output.

Pulse Delay Generator Operation 8.11.1

The instrument can be used to generate a variable pulse delay with minimal jitter. The fixed (minimum) delay between trigger input and pulse output is approximately 448ns with a typical jitter of 60ps RMS. Additional delay can be added to a resolution of 100ps. Maximum delay is 800 seconds. Maximum trigger repetition rate is 50MHz [25MHz].
Operation is set using a Pulse waveform and Triggered Burst mode, see section 14 Burst Operation more details. The pulse width and edge speeds are as defined within the pulse waveform menu.
for

Pulse Reconstruction (External Width mode) 8.11.2

In the mode described above, the pulse width is defined within the generator in response to a trigger edge. An alternative requirement is to generate pulse waveforms that directly replicate the signal applied to the trigger input. In this mode the pulse width as well as the pulse repetition rate is defined by the external signal.
The pulse edge speed can be set over a wide range, but rise time and fall time are always set equal. Typical trigger input to pulse output delay is 448ns with a typical jitter of 60ps RMS.
Asynchronous External Width mode is a variant of a Pulse Pattern waveform that can be selected from the Pattern/PRBS menu by setting the Source to External Trigg er Input. Alternatively it can be directly selected from the TRIGGER menu by pressing the
ExtWdt soft-key.
27
A confirmation message appears:
Pressing the
Trigger Input.
Yes soft-key opens the Pattern/PRBS waveform menu with the source set to External

Synchronous Pulse Reconstruction 8.11.3

Pulse patterns can also be reconstructed in a synchronous mode using a 50Mbps sampling clock. This
has the effect of reconstructing the pulses synchronously with the internal system clock which will create
an uncertainty of 20ns relative to input. Maximum input pattern bit rate is 5Mbps.
Synchronous External Width mode is a variant of a Pulse Pattern waveform that can be selected from
the Pattern/PRBS menu by setting the Source to External Modulation Input.

Modulations for External Width modes 8.11.4

Both of the modes described above can be modulated using AM, AM-SC or SUM. No other types of
modulation are possible.

8.12 Pulse Output Conditions

Setting levels, turning the output on or off, and other matters relating to the output are done from the
output menu. See section 7 Output Menu
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9 Noise Generator Operation

9.1 Capabilities

The instrument contains a full variable bandwidth noise generator with user definable PDF (probability density function). Maximum noise bandwidth is 25MHz [12.5MHz].
Noise can be used as a primary waveform (carrier waveform) or as a modulator for other waveform types.
In dual channel mode there are some restrictions on Noise; see the Dual-Channel Operations section of the Specification for details.

9.2 Setting Parame ter s for Noise

Noise Bandwidth 9.2.1

Pressing the BW soft-key displays the current noise bandwidth in the Edit Box. The bandwidth can be set anywhere between 1mHz and 25MHz [12.5MHz].

Noise Probability Density Function (PDF) 9.2.2

Pressing the PDF soft-key creates a further set of soft-keys from which the PDF can be selected.
Four standard Gaussian PDFs are provided with crest factors between 3.3 and 7.0, accessed by the soft-keys
a user-defined probability density function.
G3.3 thro G7.0 . Alternatively pressing the Arb soft-key selects an arbitrary waveform as
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