Used Agilent Agilent Used 33220A Manual

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Page 1

User’s Guide

Test Equipment Depot - 800.517.8431 - 99 Washington Street Melrose, MA 02176 - TestEquipmentDepot.com

Publication Number 33220-90002 (order as 33220-90100 manual set) Edition 4, May 2007

Agilent 33220A 20 MHz Function/ Arbitrary Waveform Generator

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Agilent 33220A at a Glance

The Agilent Technologies 33220A is a 20 MHz synthesized function generator with built-in arbitrary waveform and pulse capabilities. Its combination of bench-top and system features makes this function generator a versatile solution for your testing requirements now and in the future.

Convenient bench-top features

• 10 standard waveforms

• Built-in 14-bit 50 MSa/s arbitrary waveform capability

• Precise pulse waveform capabilities with adjustable edge time

• LCD display provides numeric and graphical views

• Easy-to-use knob and numeric keypad

• Instrument state storage with user-defined names

• Portable, ruggedized case with non-skid feet

Flexible system features

• Four downloadable 64K-point arbitrary waveform memories

• GPIB (IEEE-488), USB, and LAN remote interfaces are standard

• LXI Class C Compliant

• SCPI (Standard Commands for Programmable Instruments) compatibility

Note:

Unless otherwise indicated, this manual applies to all Serial

Numbers.

Page 3

The Front Panel at a Glance

1 Graph Mode/Local Key 2 On/Off Switch 3 Modulation/Sweep/Burst Keys 4 State Storage Menu Key 5 Utility Menu Key 6 Help Menu Key 7 Menu Operation Softkeys 8 Waveform Selection Keys

9 Manual Trigger Key (used for

Sweep and Burst only)

10 Output Enable/Disable Key 11

Knob

Cursor Keys

Sync Connector

Output Connector

Note: To get context-sensitive help on any front-panel key or menu softkey, press and hold down that key.

Page 4

The Front-Panel Display at a Glance

Menu Mode

Numeric Readout

Mode

Information

Trigger

Information

Softkey Labels

Units

Output

Status

Graph Mode

To enter or exit the Graph Mode, press the key.

Parameter

Name

Parameter

Value

Display Icon

Signal

Ground

In Graph Mode, only one parameter label is displayed for each key at one time.

Page 5

Front-Panel Number Entry

1. Use the keys below the knob to move the cursor left or right.

1. Key in a value as you would on a typical calculator.

You can enter numbers from the front-panel using one of two methods.

Use the knob and cursor keys to modify the displayed number.

2. Rotate the knob to change a digit (clockwise to increase).

Use the keypad to enter numbers and the softkeys to select units.

2. Select a unit to enter the value.

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The Rear Panel at a Glance

External 10 MHz Reference Input Terminal (Option 001 only)

Internal 10 MHz Reference Output Terminal (Option 001 only)

3 External Modulation Input Terminal

Input: External Trig/FSK/Burst Gate

Output: Trigger Output

5 USB Interface Connector 6 LAN Interface Connector 7 GPIB Interface Connector 8 Chassis Ground

Use the menu to:

• Select the GPIB address (see chapter 2).

• Set the network parameters for the LAN interface (see chapter 2).

• Display the current network parameters (see chapter 2).

Note: The External and Internal 10 MHz Reference Terminals (1 and 2, above) are present only if Option 001, External Timebase Reference, is installed. Otherwise, the holes for these connectors are plugged.

WARNING For protection from electrical shock, the power cord ground must not be

defeated. If only a two-contact electrical outlet is available, connect the instrument’s chassis ground screw (see above) to a good earth ground.

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In This Book

Quick Start Chapter 1 prepares the function generator for use and helps you get familiar with a few of its front-panel features.

Front-Panel Menu Operation Chapter 2 introduces you to the frontpanel menu and describes some of the function generator’s menu features.

Features and Functions Chapter 3 gives a detailed description of the function generator’s capabilities and o peration. You will find t his chapter useful whether you are operating the function generator from the front panel or over the remote interface.

Remote Interface Reference

to help you program the function generator over the remote interface.

Error Messages Chapter 5 lists the error messages that may appear as you are working with the function generator. Each listing contains information to help you diagnose and solve the problem.

Application Programs Chapter 6 contains several remote interface application programs to help you develop programs for your application.

Tutorial Chapter 7 discusses the fundamentals of signal generation and modulation techni ques.

Specifications Chapter 8 lists the function generator’s specifications.

Chapter 4 contains reference information

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You can contact Agilent Technologies at one of the following telephone numbers for warranty, service, or technical support information.

In the United States: (800) 829-4444 In Europe: 31 20 547 2111 In Japan: 0120-421-345

Or use our Web link for information on contacting Agilent worldwide.

Page 9

Chapter 1 Quick Start 13

To Prepare the Function Generator for Use 15 To Adjust the Carrying Handle 16 To Set the Output Frequency 17 To Set the Output Amplitude 18 To Set a DC Offset Voltage 20 To Set the High-Level and Low-Level Values 21 To Select “DC Volts” 22 To Set the Duty Cycle of a Square Wave 23 To Configure a Pulse Waveform 24 To View a Waveform Graph 25 To Output a Stored Arbitrary Waveform 26 To Use the Built-In Help System 27 To Rack Mount the Function Generator 29

Chapter 2 Front-Panel Menu Operation 31

Front-Panel Menu Reference 33 To Select the Output Termination 35 To Reset the Function Generator 35 To Output a Modulated Waveform 36 To Output an FSK Waveform 38 To Output a PWM Waveform 40 To Output a Frequency Sweep 42 To Output a Burst Waveform 44 To Trigger a Sweep or Burst 46 To Store the I nstrument State 47 To Configure the Remote Int erface 48

Chapter 3 Features and Functions 53

Output Configuration 55 Pulse Waveforms 70 Amplitude Modulation (AM) 74 Frequency Modulation (FM) 79 Phase Modulation (PM) 85 Frequency-Shift Keying (FSK) Modulation 89 Pulse Width Modulation (PWM) 93 Frequency Sweep 99 Burst Mode 106

Contents

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Contents

Triggering 115 Arbitrary Waveforms 120 System-Related Operations 126 Remote Interface Configuration 135 External Timebase Reference (Option 001) 144 Calibration Overview 146 Factory Defa ul t Sett in gs 150

Chapter 4 Remote Interface Reference 153

SCPI Command Summary 155 Simplified Programming Overview 168 Using the APPLy Command 170 Output Configuration Commands 179 Pulse Configuration Commands 192 Amplitude Modulation (AM) Commands 197 Frequency Modulation (FM) Commands 200 Phase Modulation (PM) Commands 204 Frequency-Shift Keying (FSK) Commands 207 Pulse Width Modulation (P WM) Commands 210 Frequency Sweep Commands 215 Burst Mode Commands 223 Triggering Commands 231 Arbitrary Waveform Commands 234 State Storage Commands 245 System-Related Commands 249 Interface Configuration Commands 254

Phase-Lock Commands (Option 001 Only) 258 The SCPI Status System 260 Status Reporting Commands 270 Calibration Commands 274 An Introduction to the SCPI Language 276 Using Device Clear 281

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Contents

Chapter 5 Error Messages 283

Command Errors 285 Execution Errors 288 Device Dependent Errors 303 Query Errors 304 Instrument Errors 305 Self-Test Errors 306 Calibration Errors 308 Arbitrary Waveform Errors 309

Chapter 6 Application Programs 311

Introduction 312 Program Listings 314

Chapter 7 Tutorial 321

Direct Digital Synthesis 323 Creating Arbitrary Waveforms 326 Square Waveform Generation 328 Pulse Waveform Generation 329 Signal Imperfections 330 Output Amplitude Control 332 Ground Loops 333 Attributes of AC Signals 335 Modulation 337 Frequency Sweep 342 Burst 343

Contents

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Chapter 8 Specifications 345

Waveforms 346 Waveform Characteristics 346 Common Characteristics 347 Modulation 347 Sweep 348 Burst 348 Trigger Characteristics 348 Programming Times 348 General 349 Product Dimensions 350

Index 351

Contents

Page 13

Quick Start

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Quick Start

One of the first things yo u will want to do w ith your function ge nerator is to become acquainted with the fron t panel. W e have written the exercises in this chapter to prepare the instrument for use and help you get familiar with some of its front-panel operations. This chapter is divided into the following sections:

• To Prepare the Function Generator for Use, on page 15

• To Adjust the Carrying Handle, on page 16

• To Set the Output Frequency, on page 17

• To Set the Output Amplitude, on page 18

• To Set a DC Offset Voltage, on page 20

• To Set the High-Level and Low-Level V alues, on page 21

• To Select “DC Volts”, on page 22

• To Set the Duty Cycle of a Square Wave, on page 23

• To Configure a Pulse Waveform, on page 24

• To View a Waveform Graph, on page 25

• To Output a Stored Arbitrary Waveform, on page 26

• To Use the Built-In Help System, on page 27

• To Rack Mount the Function Generator, on page 29

Page 15

Chapter 1 Quick Start

To Prepare the Function Generator for Use

1 Check the list of supplied items.

Verify that you have received the following items with your instrument. If anything is missing, please contact your nearest Agilent Sales Office.

Power Switch

• Power cord (for country of destination).

• Certificate of Calibration.

• Agilent 33220A Product Reference CD (product software, programming examples, and manuals).

• Agilent Automation-Ready CD (Agilent IO Libraries Suite).

• USB 2.0 cable.

2 C onnect the power cord and turn on the function generator.

The instrument runs a short power-on self test, which takes a few seconds. When the instrument is ready for use it displays a message about how to obtain help, along with the current GPIB address and USB identification string. The function generator powers up in the sine wave function at 1 kHz with an amplitude of 100 mV peak-to-peak (into a 50Ω termination). enable the Output

If the function generator does not turn on, verify that the power cord is firmly connected to the power receptacle on the rear p a ne l (t he po w er -line voltage is automatically sensed at power-on). You should also make sure that the function generator is connected to a power source that is energized Then, verify that the function generator is turned on.

At power-on, the

connector, press the key

Output

connecto r

is disabled. To

If the power-on self test fails, “Self-Test Failed” is displayed along with an error code. See the Agilent 33220A Service Guide for information on error codes, and for Agilent for service.

instructions on returning the function generator to

Page 16

Chapter 1 Quick Start

To Adjust the Carrying Handle

To adjust the position, grasp the handle by the sides and pull outward. Then, rotate the handle to the desired position.

Retracted

Carrying

Position

Extended

Page 17

Chapter 1 Quick Start

To Set the Output Frequency

At power-on, the function generator outputs a sine wave at 1 kHz with an amplitude of 100 mV peak-to-peak (into a 50Ω termination). The following steps show you how to change the frequency to 1.2 MHz.

1Press the “Freq” softkey.

The displayed frequency is either the power-on value or the frequency previously selected. When you change functions, the same frequency is used if the present value is valid for the new function. To set the waveform period instead, press the Freq softkey again to toggle to the Period softkey (the current selection is highlighted).

2 Enter the magnitude of the desired frequency.

Using the numeric keypad, enter the value “1.2”.

3 Select the desired units.

Press the softkey that corresponds to the desired units. When you select the units, the function generator outputs a waveform with the displayed frequency (if the output is enabled). For this example, press MHz

Note: Y keys.

ou can also enter the desired value using the knob and cursor

Page 18

Chapter 1 Quick Start

To Set the Output Amplitude

At power-on, the function generator outputs a sine wave with an amplitude of 100 mV peak-to-peak (into a 50Ω termination).

The following steps show you how to change the amplitude to 50 mVrms.

1Press the “Ampl” softkey.

The displayed amplitude is either the power-on value or the amplitude previously selected. When you change functions, the same amplitude is used if the present value is valid for the new function. To set the amplitude using a high level and low level, press the Ampl softkey again to toggle to the HiLevel and LoLevel softkeys (the current selection is highlighted).

2 Enter the magnitude of the desired amplitude.

Using the numeric keypad, enter the value “50”.

3 Select the desired units.

Press the softkey that corresponds to the desired units. When you select the units, the functio n ge ner ator out puts the wave form w ith the disp layed amplitude (if the output is enabled). For this example, press mV

Note: Y keys.

ou can also enter the desired value using the knob and cursor

RMS

Page 19

Chapter 1 Quick Start

To Set the Output Amplitude

You can easily convert the displayed amplitude from one unit to another. For example, the following steps show you how to convert the amplitude from Vrms to Vpp.

4 Enter the numeric entry mode.

Press the key to enter the numeric entry mode.

5 Select the new units.

Press the softkey that corresponds to the desired units. The displayed value is converted to the new units. For this example, press the Vpp softkey to convert 50 mVrms to its equivalent in volts peak-to-peak.

To change the displayed amplitude by decades, press the right-cursor key to move the cursor to the units on the right side of the display. Then, rotate the knob to increase or decrease the displayed amplitude by decades.

Page 20

Chapter 1 Quick Start

To Set a DC Offset Voltage

At power-on, the function generator outputs a sine wave with a dc offset of 0 volts (into a 50Ω termination). The following steps show you how to

change the offset to –1.5 mVdc.

1Press the “Offset” softkey.

The displayed off set voltage is either the power-on value or the offset previously selected. When you change functions, the same offset is used if the present value is valid for the new function.

2 Enter the magnitude of the desired offset.

Using the numeric keypad, enter the value “–1.5”.

3 Select the desired units.

Press the softkey that corresponds to the desired units. When you select the units, the functio n ge ner ator out puts the wave form w ith the disp layed offset (if the output is enabled). For this example, press mV

Note: Y keys.

ou can also enter the desired value using the knob and cursor

Page 21

Chapter 1 Quick Start

To Set the High-Level and Low-Level Values

To Set the High-Level and Lo w-Level Values

You can specify a signal by setting its amplitude and dc offset values, as described previously. Another way to set the limits of a signal is to specify its high-level (maximum) and low-level (minimum) values. This is typically convenient for digital applications. In the following example, let's set the high-level to 1.0 V and the low-level to 0.0 V.

1 Press the "Ampl" softkey to select "Ampl".

2 Press the softkey again to toggle to "HiLevel".

Note that both the Ampl and Offset softkeys toggle together, to HiLevel and LoLevel, respectively.

3 Set the "HiLevel" value.

Using the numeric keypad or the knob, select a value of "1.0 V". (If you are using the keypad, you will need to select the unit, "V", to enter the value.)

4 Press the "LoLevel" softkey and set the value.

Again, use the numeric keyp ad or the knob to enter a value of "0.0 V".

Note that these settings (high-level = "1.0 V" and low-level = "0.0 V") are equivalent to setting an amplitude of "1.0 Vpp" and an offset of "500 mVdc".

Page 22

Chapter 1 Quick Start

To Select “DC Volts”

You can select the "DC Volts" feature from the “Utility” menu, and then set a constant dc voltage as an "Offset" value. Let's set "DC Volts" = 1.0 Vdc.

1 Press and then select the DC On softkey.

The Offset value becomes selected.

2 Enter the desired voltage level as an "Offset".

Enter 1.0 Vdc with the numeric keypad or knob.

You can enter any dc voltage from -5 Vdc to +5 Vdc.

Page 23

Chapter 1 Quick Start

To Set the Duty Cycle of a Square Wave

At power-on, the duty cycle for square waves is 50%. You ca n adjust the duty cycle from 20% to 80% for output frequencies up to 10 MHz. The

following steps show you how to change the duty cycle to 30%.

1 Select the square wave function.

Press the key and then set the d esired output frequency to any value up to 10 MHz.

2Press the “Duty Cycle” softkey.

The displayed duty cycle is either the power-on value or the percentage previously selected. Th e duty cycle represents the amount of time per cycle that the square wave is at a high level (note the icon on the right side of the display).

3 Enter the desired duty cycle.

Using the numeric keypad or the knob, select a duty cycle value of “30”. The function generator adjusts the duty cy cle immediately and outputs a square wave with the specified value (if the output is enabled).

Page 24

Chapter 1 Quick Start

To Configure a Pulse Waveform

You can configure the function generator to output a pulse waveform with variable pulse width and edge time. The following steps show you

how to configure a 500 ms pulse waveform with a pulse width of 10 ms and edge times of 50 ns.

1 Select the pulse function.

Press the key to select the pulse function and output a pulse waveform with the default parameters.

2 Set the pulse period.

Press the Period softkey and then set the pulse period to 500 ms.

3 Set the pulse width.

Press the Width softkey and then set the pulse width to 10 ms. The pulse width represents the time from the 50% threshold of the rising edge to the 50% threshold of the next falling edge (note the display icon).

4 Set the edge time for both edges.

Press the Edge Time softkey and then set the edge time for both the rising and falling edges to 50 ns. The edge time represents the time from the 10% threshold to the 90% threshold of each edge (note the display icon

Page 25

Chapter 1 Quick Start

To View a Waveform Graph

In the Graph Mode, you can view a graphical representation of the current waveform parameters. The softkeys are listed in the same order as in the normal display mode, and they perform the same functions. However, only one label (for example, Freq or Period) is displayed for each softkey at one time.

1 Enable th e Graph Mode.

Press the key to enable the Graph Mode. The na me of the selected parameter’s numeric value field are both highlighted.

2 Select the desired paramet er.

To select a specific parameter, note the softkey labels at the bottom of the display.

• As in the normal disp lay mode , you can e dit numb ers using either the

•

• To exit the Graph Mode, press again.

parameter,

For example

numeric keypad or the knob and cursor keys. Param ete rs w h ic h n o rmally tog g le when you p re ss a key a seco nd t im e

also toggle in the Graph Mode. Howev er, you can see on ly on e label for each softkey at one time (for example, Freq or Period).

The key also serves as a key to restore front-panel control after remote interface operations.

shown in the up per-left corne r of the display, a nd the

, to select period, press the Period softkey.

currently

Page 26

Chapter 1 Quick Start

To Output a Stored Arbitrary Waveform

There are five built-in arbitrary waveforms stored in non-volatile memory

The following steps show you how to output the built-in “exponential fall” waveform

For information on creating a custom arbitrary waveform, refer to “To Create and Store an Arbitrary Waveform” on page 120.

1 Select the arbitrary waveform function.

When you press the key to select the arbitrary waveform function, a temporary message is displayed indicating which waveform is currently selected (the default is “exponential rise”).

2 Select the active waveform.

Press the Select Wform softkey and then press the Built-In softkey to select from the five built-in waveforms. Then press the Exp Fall softkey. The waveform is output using the present settings for frequency, amplitude, and offset unless you change them.

from the front panel.

The selected waveform is now assigned to the key. Whenever you press this key, the selected arbitrary waveform is output. To quickly determine which arbitrary waveform is currently selected, press .

Page 27

Chapter 1 Quick Start

To Use the Built-In Help System

The built-in help system is designed to provide context-sensitive assistance on any front-panel key or menu softkey. A list of help topics is also available to assist you with several front-panel operations.

1 View the help information for a function key.

Press and hold down the key. If th e message contains information than will fit on the di spla y, pre s s th e ↓ softkey or turn the knob clockwise to view the remaining information.

Press DONE to exit Help.

2 View the help information for a menu softkey.

Press and hold down the Freq softkey. information than will fit on the di spla y, pre s s th e ↓ softkey or rotate the knob clockwise to view the remaining information.

Press DONE to exit Help.

If the message con tai ns

Page 28

Chapter 1 Quick Start

To Use the Built-In Help System

3 View the list of help topics.

Press the key to view the li st of available help topics. To scroll through the list, press the ↑ or ↓ softkey or rotate the knob. Sele ct the third topic “Get HELP on any key” and then press SELECT.

Press DONE to exit Help.

4 View the help information for displayed messages.

Whenever a limit is exceeded or an y other invali d config uration i s found, the function generator will display a message. For example, if you enter a value that exceeds the frequency limit for the selected function, a message will be displayed. The built-in help system provides additional information on the most recent message to be displayed.

Press the k ey, select the first top ic “ and then press SELECT.

Press DONE to exit Help.

Local Language Help: The built-in help system in available in multiple languages. All messages, context-sensitive help, and help topics appear in the selected language. The menu softkey labels and status line messages are not translated.

To select the local language, press the key, press the System softkey, and then press the Help In softkey. Select the desired language.

View the last message displayed”,

Page 29

Chapter 1 Quick Start

To Rack Mount the Function Generator

You can mount the Agilent 33220A in a standard 19-inch rack cabinet using one of two optional kits available. Instructions and mounting hardware are included with each rack-mounting kit. Any Agilent System II instrument of the same size can be rack-mounted beside the Agilent 33220A.

Note:

before rack-mounting the instrument.

Remove the carrying handle, and the front and rear rub ber bumpers

To remove the handle, rotate it to vertical and pull the ends outward.

Front

To remove the rubber bumper, stretch a corner and then slide it off.

Rear (bottom view)

Page 30

Chapter 1 Quick Start

To Rack Mount the Function Generator

To rack mount a single instrument, order adapter kit 5063-9240.

To rack mount two instruments side-by-side, order lock-link kit 5061- 8769 and flange kit 5063-9212. Be sure to use the support rails in the rack cabinet.

In order to prevent overheating, do not block the flow of air into or out of the instrument. Be sure to allow enough clearance at the rear, sides, and bottom of the instrument to permit adequate internal air flow.

Page 31

Front-Panel Menu Operation

Page 32

Front-Panel Menu Operation

This chapter introduces you t o the fro nt-pane l keys and menu oper ation. This chapter does not give a deta iled descri ption of eve ry front-pa nel key or menu operation. It does, however, give you an overview of the frontpanel menus and many front-panel operations. See chapter 3 “Features and Functions,” starting on page 53, for a complete discussion of the function generator’s capabilities and operation.

• Front-Panel Menu Reference, on page 33

• To Select the Output Termination, on page 35

• To Reset the Function Generator, on page 35

•To Output a Modulated Waveform, on page 36

• To Output an FSK Waveform, on page 38

•To Output a PWM Waveform, on page 40

• To Output a Frequency Sweep, on page 42

• To Output a Burst Waveform, on page 44

• To Trigger a Sweep or Burst, on page 46

• To Store the Instrument State, on page 47

• To Configure the Remote Interface, on page 48

Page 33

Chapter 2 Front-Panel Menu Operation

Front-Panel Menu Reference

This section gives an overview of the front-panel menus. The remainder of this chapter contains examples of using the front-panel menus.

Configure the modulation parameters for AM, FM, PM, FSK and PWM.

• Select the modulation type.

• Select an internal or external modulation source.

• Specify AM modulation depth, modulating frequency, and modulation shape. Specify FM frequency deviation, modulating frequency, and modulation shape.

•

Specify PM phase deviation, modulating frequency, and modulation shape.

• Specify FSK “hop” frequency and FSK rate.

• Specify PWM deviation, modulating frequency, and modulation shape.

Configure the parameters for frequency sweep.

• Select linear or logarithmic sweeping.

• Select the start/stop frequencies or

• Select the time in seconds required to complete a sweep.

• Specify a marker frequency.

• Specify an internal or external trigger source for the sweep.

• Specify the slope (rising or falling edge) for an external trigger source.

• Specify the slope (rising or falling edge) of the “Trig Out” signal.

Configure the parameters for burst.

center/ span frequencies.

• Select the triggered (N Cycle) or externally-gated burst mode.

• Select the number of cycles per burst (1 to 50,000, or Infinite).

• Select the starting phase angle of the burst (-360° to +360°).

• Specify the time from the start of one burst to the start of the next burst.

• Specify an internal or external trigger source for the burst.

• Specify the slope (rising or falling edge) for an external trigger source.

• Specify the slope (rising or falling edge) of the “Trig Out” signal.

Page 34

Chapter 2 Front-Panel Menu Operation

Front-Panel Menu Reference

Store and recall instrument states.

• Store up to four instrument states in non-volatile memory.

• Assign a custom name to each storage location.

• Recall stored instrument states.

• Restore all instrument settings to their factory default values.

• Select the instrument’s power-on configuration (last or factory default).

Configure system-related parameters.

• Generate a dc-only voltage level.

• Enable/disable the Sync signal which is output from the “Sync” connector.

• Select the output termination (1Ω to 10 kΩ, or Infinite).

• Enable/disable amplitude autoranging.

• Select the waveform polarity (normal or inverted).

• Select the GPIB address.

• Specify the LAN configuration (IP address and network configuration). Select how periods and commas are used in numbers displayed on the front panel.

•

• Select the local language for front-panel messages and help text.

• Enable/disable the tone heard when an error is generated.

• Enable/disable the display bulb-saver mode.

• Adjust the contrast setting of the front-panel display.

• Perform an instrument self-test.

• Secure/unsecure the instrument for calibration and perform manual calibrations.

• Query the instrument’s firmware revision codes.

View the list of Help topics.

• View the last message displayed.

• View the remote command error queue.

• Get HELP on any key.

• How to generate a dc-only voltage level.

• How to generate a modulated waveform.

• How to create an arbitrary waveform.

• How to reset the instrument to its default state.

• How to view a waveform in the Graph Mode.

• How to synchronize multiple instruments.

• How to obtain Agilent Technical Support.

Page 35

Chapter 2 Front-Panel Menu Operation

To Select the Output Termination

The Agilent 33220A has a fixed series output impedance of 50 ohms to the front-panel Output connector. If the actual load impedance is different than the value specified, the displayed amplitude and offset levels will be incorrect. The load impedance setting is simply provided as a convenience to ensure that the displayed voltage matches the expected load.

1Press .

2 Navigate the menu to set the output termination.

Press the Output Setup softkey and then select the Load softkey.

3 Select the desired output termination.

Use the knob or numeric keypad to select the desired load impedance or press the Load softkey again to choose “High Z”.

To Reset the Function Generator

To reset the instrument to its factory default state, press and then select the Set to Defaults softkey. Press YES to confirm the operation.

For a complete listing of the instrument’s power-on and reset conditions, see “Agilent 33220A Factory Default Settings” on page 151.

Page 36

Chapter 2 Front-Panel Menu Operation

To Output a Modulated Waveform

A modulated waveform consists of a carrier and a modulating waveform. In AM (amplitude modulation), the amplitude of the carrier is varied by the amplitude of the modulating waveform. For this example, you will output an AM waveform with 80% modulation depth. The carrier will be a 5 kHz sine wave and the modulating waveform will be a 200 Hz sine wave.

1 Select the function, frequency, and amplitude of the carrier.

Press and then press the Freq, Ampl, and Offset softkeys to configure the carrier waveform.

with an amplitude of 5 Vpp.

2 Select AM.

Press and then select “AM” using the Type softkey. Notice that a status message “AM by Sine” is shown in the upper-left corner of the display.

3 Set the modulation depth.

Press the AM Depth softkey and then set the value to 80% using the numeric keypad or the knob and cursor keys.

For this example, select a 5 kHz sine wave

Page 37

Chapter 2 Front-Panel Menu Operation

To Output a Modulated Waveform

4 Set the modu lating frequency.

Press the AM Freq softkey and then set the value to 200 Hz usi ng the numeric keypad or the knob and cursor keys.

5 Select the modulating waveform shape.

Press the Shape softkey to select the shape of the modulating waveform. For this example, select a sine wave.

At this point, the function generator outputs an AM waveform with the specified modulation parameters (if the output is enabled).

6 View the waveform.

Press t

To turn off the Graph Mode, press

o view the waveform parameters.

again

Page 38

Chapter 2 Front-Panel Menu Operation

To Output an FSK Waveform

You can configure the function generator to “shift ” its output frequency between two preset values using FSK modul ati on. The ra te at which the output shifts between the tw o freq uencies (cal led the “ca rrier freq ue ncy” and the “hop frequency”) is determined by the internal rate generator or the signal level on the rear-panel Trig In connector. For this example,

you will set the “carrier” frequency to 3 kHz and the “hop” frequency to 500 Hz, with an FSK rate of 100 Hz.

1 Select the function, frequency, and amplitude of the carrier.

Press and then press the Freq, Ampl, and Offset softkeys to configure the carrier waveform.

with an amplitude of 5 Vpp.

2 Select FSK.

Press and then select “FSK” using the Ty pe softkey. Notice that a status message “FSK” is shown in the upper-left corner of the display.

For this example, select a 3 kHz sine wave

Page 39

Chapter 2 Front-Panel Menu Operation

To Output an FSK Waveform

3 Set the “hop” frequency.

Press the Hop Freq softkey and then set the value to 500 Hz using the numeric keypad or the knob and cursor keys.

4 Set the FSK “shift” rate.

Press the FSK Rate softkey and then set the value to 100 Hz using the numeric keypad or the knob and cursor keys.

At this point, the function generator outputs an FSK waveform (if the output is enabled).

5 View the waveform.

Press t

To turn off the Graph Mode, press

o view the waveform parameters.

again

Page 40

Chapter 2 Front-Panel Menu Operation

To Output a PWM Waveform

You can configure the function generator to output a pul se wi dth modulated (PWM) waveform. The Agilent 33220A provides PWM for pulse carrier waveforms, and PWM is the only type of modulation supported for pulse waveforms. In PWM, the pulse wi dth or duty cycle of the carrier waveform is varied according to the modulating waveform. You can specify either a pulse wi dth and widt h deviat ion, or a pulse duty cycle and duty cycle deviation, the deviation to be controlled by the modulating waveform.

For this example, you will specify a pulse width and pulse width deviation for a 1 kHz pulse waveform with a 100 Hz sine wave modulating waveform.

1 Select the carrier waveform parameters.

Press and then press the Freq, Ampl, Offset, Width, and Edge Time softkeys to configure the carrier waveform. For this example, select

a 1 kHz pulse waveform with an amplitude of 1 Vpp, a zero offset, a pulse width of 100 µs, and an edge time of 50 ns.

2 Select PWM.

Press (PWM is the only modulatio n typ e for Pulse). Notice that a status message "PWM by Sine" is shown in the upper-left corner of the

display.

3 Set the width deviation.

Press the Width Dev softkey and set the va lue to 20 µs using the numeric keypad or the knob and cursor keys.

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Chapter 2 Front-Panel Menu Operation

To Output a PWM Waveform

4 Set the modu lating frequency.

Press the PWM Freq softkey and then set the value to 5 Hz using the numeric keypad or the knob and cursor keys.

5 Select the modulating waveform shape.

Press the Shape softkey to select the shape of the modulating waveform. For this example, select a sine wave.

At this point, the function generator outputs a PWM waveform with the specified modulation parameters (if the output is enabled).

6 View the waveform.

Press to view the waveform and paramet ers.

To turn off the Graph Mode, press again.

Of course, to really view the PWM wavef orm, you would need to ou tput it to an oscilloscope. If you do this, you will see how the pulse width varies, in this case, from 80 to 120 µs. At a modulation frequency of 5 Hz, the deviation is quite visible.

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Chapter 2 Front-Panel Menu Operation

To Output a Frequency Sweep

from 50 Hz to 5 kHz. You will not change the other parameters from their default settings: internal sweep trigger, linear spacing, and 1 second sweep time.

1 Select the function and amplitude for the sweep.

For sweeps, you can select sine, square, ramp, or arbitrary waveforms (pulse, noise, and dc are not allowed) . For this example, select a sine wave

with an amplitude of 5 Vpp.

2 Select the sweep mode.

Press and then verify that the linear sweep mode is currently selected. Notice that a status message “Linear Sweep” is shown in the upper-left corner of the display.

3 Set the start frequency.

Press the Start softkey and then set the value to 50 Hz using the numeric keypad or the knob and cursor keys.

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Chapter 2 Front-Panel Menu Operation

To Output a Frequency Sweep

4 Set the stop frequency.

Press the Stop softkey and then set the value to 5 kHz using the numeric keypad or the knob and cursor keys.

At this point, the function generator outputs a continuous sweep from 50 Hz to 5 kHz (if the output is enabled).

Note: If desired, you can set the frequency boundaries of the sweep using a center frequency and frequency span. These parameters are similar to the start frequency and stop frequency and are included to give you added flexibility. To achieve the same results, set the center frequency to 2.525 kHz and the frequency span to 4.950 kHz.

5 View the waveform.

Press t

To turn off the Graph Mode, press

You can generate a single frequency sweep by pressing the key. For more information, see “To Trigger a Sweep or Burst” on page 46.

o view the waveform parameters.

again

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Chapter 2 Front-Panel Menu Operation

To Output a Burst Waveform

You can configure the function generator to output a waveform with a specified number of cycles, called a burst. You can output the burst at a rate determined by the internal rate generator or the signal level on the rear-panel Trig In connector. For this example, you will output a

three-cycle sine wave with a 20 ms burst period. You will not change the other parameters from their default settings: internal burst source and 0 degree starting phase.

1 Select the function and amplitude for the burst.

For burst waveforms, you can select sine, square, ramp, pulse, or arbitrary waveforms (noise is allowed only in the “gated” burst mode and dc is not allowed). For this example, select a sine wave with an

amplitude of 5 Vpp.

2 Select the burs t mode.

Press and then verify that the “N Cycle” (inte rnally-triggered) mode is currently selected. Notice that a status message “N Cycle Burst” is shown in the upper-left corner of the display.

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Chapter 2 Front-Panel Menu Operation

To Output a Burst Waveform

3 Set the burst count.

Press the # Cycles softkey and then set the count to “3” u sing the numeric keypad or knob.

4 Set the burst period.

Press the Burst Period softkey and then set the period to 20 ms using the numeric keypad or the knob an d cursor keys. The burst period sets the time from the start of one burst to the start of the next burst (note the display icon).

At this point, the function generator outputs a continuous three-cycle burst (if the output is enabled).

5 View the waveform.

Press t

To turn off the Graph Mode, press

You can generate a single burst (with the specified count) by pressing the key. For more information, see “To Trigger a Sweep or Burst” on page 46.

You can also use an external gate signal to either turn the burst signal “on” or “off” based on the external signal applied to the rear-panel Tri g In connector. For more information, see “Burst Mode” on page 106.

o view the waveform parameters.

again

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Chapter 2 Front-Panel Menu Operation

To Trigger a Sweep or Burst

You can issue triggers from the front pa nel for sweeps and b ursts using a manual trigger or an internal trigger.

• Internal or “automatic” triggering is enabled with the default settings of the function generator. In this mode, the function generator outputs continuously when the sweep or burst mode is selected.

• Manual triggering init iates one sweep o r outp uts one b urst each ti me you press the key from the front-panel. Continue pressing this key to re-trigger the function generator.

• The key is disabled when in remote (the remote icon turns on while in remote) and when a function other than sweep or burst is currently selected (or when the output is disabled). The key flashes off momentarily when us ing a manual trigger.

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Chapter 2 Front-Panel Menu Operation

To Store the Instrument State

You can store the instrument state in one of four non-volatile storage locations. A fifth storage location automatically holds the power-down configuration of the instrument. When power is restored, the instrument can automatically return to its state before power-down.

1 Select the desired storage location.

Press and then select the Store State softkey.

2 Select a custom name for the selected location.

If desired, you can assign a custom name to each of the four locations.

• The name can contain up to 12 characters. The first character be a letter but the remaining cha racters can be letters, numbers the underscore character (“_”).

• To add additional characters, press the right-cursor key until the cursor is to the right of the existing name and then turn the knob.

• To delete all characters to the right of the cursor position, press .

• To use numbers in the name, you can enter them directly from the numeric keypad. Use the de cimal point from the numeric keypad to add the underscore character (“_”) to the name.

must

, or

3 St o re the instrument state.

Press the STORE STATE softkey. The instrument stores the selected function, frequency, amplitude, dc offset, duty cycle, symmetry, as well as any modulation parameters in use. The instrument does not store volatile waveforms created in the arbitrary waveform function.

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Chapter 2 Front-Panel Menu Operation

To Configure the Remote Interface

The Agilent 33220A supports remote interface communication using a choice of three interfaces: GPIB, USB, and LAN (LXI Class C compliant). All three interfaces are "live" at power up. The following sections tell how to configure the remote interface from the instrument front panel.

Note: Two CDs, provided with your instrument, contain connectivity software to enable communications over the remote interfaces. See “Connectivity Software and Product CDs” on page -135 for further information on these CDs and the software they contain.

GPIB Configuration

You need only select a GPIB address.

1 Selec t the “I/O” menu.

Press and then press the

2 Set the GPIB address.

Use the knob and cursor keys or the numeric keypad to select a GPIB address in the range 0 through 30 (the factory default is “10”).

The GPIB address is shown on the front-panel display at power-on.

3 Exit the menu.

Press the DONE softkey.

I/O

softkey.

USB Configuration

The USB interface requires no front panel configuration parameters. Just connect the Agilent 33220A to your PC with the appropriate USB cable. The interface will self configure. Press the Show USB Id softkey in the “I/O menu” to see the USB interface identification string. Both USB

1.1 and USB 2.0 are supported.

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Chapter 2 Front-Panel Menu Operation

To Configure the Remote Interface

LAN Configuration

There are several parameters that you may need to se t to establish network communication using the LAN interface. Primarily, you will need to establish an IP address. You may need to contact your network administrator for help in establishing communication with the LAN interface.

1 Select the “I/O” menu.

Press and then press the

2 Selec t the “LA N” menu.

Press the

You can select

Config

Press

LAN

softkey.

Modify Settings

to view the current LA N settings (including the MA C address).

Modify Settings

I/O

softkey.

to chang e the LAN settings, or

Current

From this menu, you can select Reset LAN to restart the LAN, IP Setup to set an IP address and related parameters, DNS Setup to configure DNS, or Password to set a password for the Web Server Interface.

Note: To se t a password us e the kn ob and cursor keys (us e to delete all characters to the right of the cursor position). The Web Server

Interface will prompt for the password to protect certain windows. See “Agilent 33220A Web Interface” on page -143 for further information.

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Chapter 2 Front-Panel Menu Operation

To Configure the Remote Interface

3 Establish an “IP Setup.”

To use the Agilent 33220A on the network, you must first establish an IP setup, including an I P addre ss, and pos sib ly a su bnet mask and gate way address. Press the IP Setup softkey. By default, bo th DHCP and Auto IP are set to On.

With DHCP On, an IP address will automatically be set by DHCP (Dynamic Host Configuration Pr otocol) when you connect the Agilent 33220A to the network, provided the DHCP server is found and is able to do so. DHCP also automatically deals with the subnet mask and gateway address, if required. This is typically the easiest way to establish LAN

communication for your instrument. All you need to do is leave DHCP On.

With Auto IP On, if DHCP fails to assign an IP address, Auto IP will attempt to do so after a time-out period.

However, if you cannot establish communication by means of DHCP or Auto IP, you will need to manually set an IP address, and a subnet mask and gateway address if they are in use. Follow these steps:

a. Set the “IP Address.” Press the softkeys to select DHCP Off and

Auto IP Off. The manual selection s oftkeys appea r and the current IP address is displayed:

Contact your network administrator for the IP address to use. All IP addresses take the dot-notation form "nnn.nnn.nnn.nnn" where "nnn" in each case is a byte value in the range 0 through 255. You can enter a new IP address using the numeric keypad (not the knob). Just type in the numbers and the period delimiters using the k eypad. Use the left cursor key as a backspace key. Do not enter leading zeros. For further informati on, s ee “More about I P Address es and Do t Nota tion ” at the end of this section.

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Chapter 2 Front-Panel Menu Operation

To Configure the Remote Interface

b. Set the “Subnet Mask.” The subnet mask is required if your

network has been divided into subnets. Ask your network administrator whether a subnet mask is needed, and for the correct mask. Press the Subnet Mask softkey and enter the subnet mask in the IP address format (using the keypad).

c. Set the “Default Gateway.” The gateway address is the address of

a gateway, which is a device that connects two networks. Ask your network administrator whether a gateway is in use and for the correct address. Press the Default Gateway softkey and enter the gateway address in the IP address format (using the keypad).

d. Exit the “IP Setup” menu. Press DONE to return to the "Modify

Settings" menu.

4 Configure the “DNS Setup” (optional).

DNS (Domain Name Service) is an Internet service that translates domain names into IP addresses. Ask your network administrator whether DNS is in use, and if it is, for the host name, domain name, and DNS server address to use.

Start at the “Modify Settings” menu.

Press the DNS Setup softkey to display the “Host Name” field.

a. Set the “Host Name.” Enter the host name. The host name is the

host portion of the domain name, which is translated into an IP address. The host name is entered as a string using the knob and cursor keys to select and change characters. The host name may

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Chapter 2 Front-Panel Menu Operation

To Configure the Remote Interface

include letters, numbers, and dashes (“ -”). You can use the keypad for the numeric characters only.

Press to delete all characters to the right of the cursor position.

b. Set the “Domain Name.” Press the Domain Name softkey and ent er

the domain name. The domain name is translated into an IP address. The domain name is entered as a string using the knob and cursor keys to select and change characters. The domain name may include letters, numbers, dashes (“-”), and periods (“.“). You can use the keypad for the numeric characters only.

Press to delete all characters to the right of the cursor position.

c. Set the “DNS Server” address. Press the DNS Server softkey and

enter the address of the DNS server in the IP address format (using the keypad).

5 Exit the menus.

Press DONE to exit each menu in turn, or p menu directly.

More about IP Addresses and Dot Notation

Dot-notation addresses ("nnn.nnn.nnn.nnn" where "nnn" is a byte value) such as IP addresses must be expressed with care. This is because most web software on the PC will interpret byte values with leading zeros as octal numbers. Thus, "255.255.020.011" is actually equivalent to the decimal "255.255.16.9" rather than "255.255.20.11" because ".020" is interpreted as "16" expressed in octal, and ".011" as "9". To avoid confusion it is best to use only decimal expressions of byte values (0 to

255), with no leading zeros.

ress

to exit the “Utility”

The Agilent 33220A assumes that all IP addresses and other dotnotation addresses are expressed as decimal byte values, and strips all leading zeros from these byte values. Thus, if you try to enter "255.255.020.011" in the IP address field, it becomes "255.255.20.11" (a purely decimal expression). You should enter exactly the same expression, "255.255.20.11" in your PC web software to address the instrument. Do not use "255.255.020.011"—the PC will interpret that address differently due to the leading zeros.

Page 53

Features and Functions

Page 54

Features and Functions

This chapter makes it easy to look up all the details about a particular feature of the function generator. It covers both front panel and remote interface operation. You may want to read chapter 2, “Front-Panel Menu Operation” first. See chapter 4, “Remote Interface Reference” for a detailed discussion of the syntax of the SCPI commands to program the function generator. This chapter is divided into the following sections:

• Output Configuration, on page 55

•Pulse Waveforms, on page 70

• Amplitude Modulation (AM), on page 74

• Frequency Modulation (FM), on page 79

• Phase Modulation (PM), on page 85

• Frequency-Shift Keying (FSK) Modulation, on page 89

• Pulse Width Modulati on (PWM), on page 93

• Frequency Sweep, on page 99

•Burst Mode, on page 106

•Triggering, on page 115

• Arbitrary Waveforms, on page 120

• System-Related Operations, on page 126

• Remote Interface Configuration, on pa ge 135

• External Timebase Reference (Option 001), on page 144

• Calibration Overview, on page 146

• Factory Default Sett ing s, on page 150

Throughout this manual “default” states and values are identified. These are the power-on default states provided you have not enabled the power-down recall mode (see “Instrument State Storage” on page 126).

Throughout this manual, the following conventions are used for SCPI command syntax for remote interface programming:

• Square brackets ( [ ] ) indicate optional keywords or parameters.

• Braces ( { } ) enclose pa rameters within a command string.

• Triangle brackets ( < > ) enclose parameters for which you must substitute a value.

• A vertical bar ( | ) separates multiple parameter choices.

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Chapter 3 Features and Functions

Output Configuration

This section contains information to help yo u configure the function generator for outputting waveforms. You may nev er have to change some of the parameters discussed here, but they are provided to give you the flexibility you might need.

Output Function

The function generator can output five standard waveforms (sine, square, ramp, pulse, and noise), plus dc. You can also select one of five built-in arbitrary waveforms or create your own custom waveforms. You can internally modulate sine, square, ramp, and arbitrary waveforms using AM, FM, PM, or FSK. You can also modulate pulse using PWM. Linear or logarithmic frequency sweeping is available for sine, square, ramp, and arbitrary waveforms. You can generate a burst waveform using any of the standard or arbi trary waveforms (but not dc). The default function is sine wave.

• The table below shows which output functions are allowed with modulation, sweep, and burst. Each “ • ” indicates a valid com bina tion If you change to a function that is not allowed with modulation, sweep, or burst, then t he modulation or mode is turned off.

Sine Square Ramp Pulse Noise DC Arb

AM, FM, PM, FSK Carrier

PWM Carrier •

Sweep Mode •• • •

Burst Mode •• •• •

Allowed in the External Gated burst mode only.

•• • •

•

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Chapter 3 Features and Functions

Output Configuration

• Function Limitations: If you change to a function whose maximum frequency is less than that of the current function, the frequency is adjusted to the maximum value for the new function. For example, if you are currently outputting a 20 MHz sine wave and then change to the ramp function, the function generator will automatically the output frequency to 200 kHz (the upper limit for ramps).

• Amplitude Limitations: If you change to a function whose maximum amplitude is less than that of the current function, the amplitude is automatically adjusted to the maximum value for the new function. This may occur when the output units are Vrms or dBm due to the differences in crest factor fo r the various output functions.

For example, if you output a 5 Vrms square wave (into 50 ohms) and then change to the sine wave function, the function generator will automatically adjust the output amplitude to 3.536 Vrms (the upper limit for sine in Vrms).

• Front-Panel Operation: To select a function, press any key in the top row of function keys. Press to output the arbitrary waveform currently selected. To view the other arbitrary waveform choices, press the Select Wform softkey.

adjust

To select dc volts from the front panel, press and then select the DC On softkey. Press the Offset softkey to enter t he desired offset voltage level.

• Remote Interface Operation:

FUNCtion {SINusoid|SQUare|RAMP|PULSe|NOISe|DC|USER}

You can also use the amplitude, and offset with a single command.

APPLy

command to select the function, frequency

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Chapter 3 Features and Functions

Output Configuration

Output Frequency

As shown below, th e ou t pu t fr eq ue n c y rang e de p en d s on th e fu nc t i on currently selected. The default frequency is 1 kHz for all functions.

Function Minimum Frequency Maximum Frequency

Sine

Square

Ramp

Pulse

Noise, DC

Arbs

1 µHz 1 µHz 1 µHz

500 µHz

Not Applicable

1 µHz

20 MHz 20 MHz

200 kHz

5 MHz

Not Applicable

6 MHz

adjust

the output frequency to 200 kHz (the upper limit for ramps).

• Burst Limitation: For internally-triggered bursts, the minimum frequency is 2.001 mHz. For sine and square waveforms, frequencies above 6 MHz are allowed only with an “infinite” burst count.

Duty Cycle Limitations

•

: For square waveforms, the function generato may not be able to use the full range of duty cycle values at higher frequencies as shown below.

20% to 80% (frequency <

10 MHz)

40% to 60% (frequency > 10 MHz)

If you change to a frequency that cannot produce the current duty cycle the duty cycle is automatically adjusted to the maximum value for the new frequency. For example, if you currently have the duty cycle set to 70% and then change the frequency to 12 MHz, the function generator will automatically adjust the duty cycle to 60% (the upper limit for this frequency).

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Chapter 3 Features and Functions

Output Configuration

• Front-Panel Operation: To set the output frequency, press the Freq softkey for the selected function. Then use the knob or numeric keypad to enter the desired frequency. To set the waveform period instead, press the Freq softkey again to toggle to the Period softkey.

• Remote Interface Operation:

FREQuency {<frequency>|MINimum|MAXimum}

You can also use the amplitude, and offset with a single command.

APPLy

command to select the function, frequency

Output Amplitude

The default amplitude is 100 mVpp (into 50 ohms) for all functions.

• Offset Voltage Limitations: The relationship between output amplitude and offset voltage is shown below. Vmax is the maximum peak voltage for the selected output termination (5 volts for a 50Ω load or 10 volts for a high-impedance load).

Vpp <

• Limits Due to Output Termination: If you change the output termination setting, the displayed output amplitude will be adjusted (and no error will be generated). For example, if you set the amplitude to 10 Vpp and then change the output termination from 50 ohms to “high impedance”, the amplitude displayed on the function generator’s front-panel will double to 20 Vpp. If you change from “high impedance” to 50 ohms, the displayed amplitude will drop in half. For more information, see “Output Termination” on page 63.

• Limits Due to Units Selection: In some cases, the amplitude limits are determined by the ou tput units selected . This may occur when the units are Vrms or dBm due to the differences in crest factor for the various output functions. For example, if you output a 5 Vrms square wave (into 50 ohms) and then change to the sine wave function, the function generator will automatically adjust the output amplitude to 3.536 Vrms (the upper limit for sine waves in Vrms).

2 X (Vmax –|Voffset|)

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Chapter 3 Features and Functions

Output Configuration

• You can set the output amplitude in Vpp, Vrms, or dBm. For more information, see “Output Units” on page 62.

• You cannot specify the output amplitude in dBm if the output termination is currently set to “high impedance”. The units are automatically converted to Vpp. For more information, see “Output

Units” on page 62.

• Arbitrary Waveform Limitations: For arbitrary waveforms, the maximum amplitude will be limited if the waveform data points do not span the For example of values between ±1 and therefore its maximum ampli tude is limite d to 6.087 Vpp (into 50 ohms).

• While changing amplitude, you may notice a momentary disruption in the output waveform at certain voltages due to switching of the output attenuators. To prevent this disruption in the output, you can disable the voltage autoranging feature as described on page 66.

full range of th e outpu t DAC (Digital- to-Analog Conve rter).

, the built-in “Sinc” waveform does not use the full range

• You can also set the amplitude (with an associated offset vo ltage) by specifying a high level and low level. For example, if you set the high level to +2 volts and the low level to -3 volts, the resulting amplitude is 5 Vpp (with an offset voltage of -500 mV).

• For dc volts, the output level is actually controlled by setting the offset voltage. You can set the dc level to any value between ±5 Vdc into 50 ohms or ±10 Vdc into an open circuit. See “DC Offset Voltage”

on the following page for more information. To select dc volts from the front panel, press and then select the

DC On softkey. Press the Offset softkey to set the desired offset voltage level.

• Front-Panel Operation: softkey for the selected function. Then use the knob or numeric keypad to enter the desired amplitude. To set the amplitude using a high level and low level, press the Ampl softkey again to to ggl e to t he HiLevel and LoLevel softkeys.

To set the output amplitude, press the

Ampl

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Chapter 3 Features and Functions

Vpp

---

Output Configuration

• Remote Interface Operation:

VOLTage {<amplitude>|MINimum|MAXimum}

Or, you can set the amplitude by specifying a high level and low level using the following commands.

VOLTage:HIGH {<voltage>|MINimum|MAXimum} VOLTage:LOW {<voltage>|MINimum|MAXimum}

You can also use the amplitude, and offset with a single command.

APPLy

command to select the function, frequency

DC Offset Voltage

The default offset is 0 volts for all functions.

Limits Due to Amplitude

• output ampl itude i s sh own belo w. Vmax is the maximum peak vol tage for the selected output termination (5 volts for a 50Ω load or 10 volts for a high-impedance load).

|Voffset| <

If the specified offset voltage is not valid, the function generator will automatically adjust it to the maximum dc voltage allowed with the amplitude specified.

• Limits Due to Output Termination: The offset limits are determined by the current output termination setting. For example, if you set the offset to 100 mVdc and then change the output termination from 50 ohms to “high impedance”, the offset voltage displayed on the function generator’s front-panel w ill double to 200 mVdc (and no error will be generated). If you change from “high impedance” to 50 ohms, the displayed offset will drop in half. See “Output Termination” on

page 63 for more information.

Vmax –

: The relatio nship between offs et voltage and

------2

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Chapter 3 Features and Functions

Output Configuration

• Arbitrary Waveform Limitations: For arbitrary waveforms, the maximum points do not Converter). the full range of values between ±1 and therefore its maximum offset is limited to 4.95 volts (into 50 ohms).

• You can also set the offset by specifying a high level and low level. For example, if you set the high level to +2 volts and the low level to

-3 volts, the resulting amplitude is 5 Vpp (with an offset voltage of

-500 mV).

offset and am p lit u d e w ill be lim it ed if the w aveform data

span the

For example, the built-in “Sinc” waveform does not use

full range of the output DAC (Digital-to-Analog

• For dc volts, the output level is actually controlled by setting the offset voltage. You can set the dc level to any value between ±5 Vdc into 50 ohms or ±10 Vdc into an open circuit.

To select dc volts from the front panel, press and then select the DC On softkey. Press the Offset softkey to set the desired offset voltage level.

• Front-Panel Operation: for the selected function. Then use the knob or numeric keypad to enter the desired offset. To set the offset using a high level and low level, press the Offset softkey again to toggle to the HiLevel and LoLevel softkeys.

• Remote Interface Operation:

VOLTage:OFFSet {<offset>|MINimum|MAXimum}

Or, you can set the offset by specifying a high level and low level using the following commands.

VOLTage:HIGH {<voltage>|MINimum|MAXimum} VOLTage:LOW {<voltage>|MINimum|MAXimum}

You can also use the amplitude, and offset with a single command.

To set the dc offset, pre ss the

APPLy

command to select the function, frequency

Offset

softkey

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Chapter 3 Features and Functions

Output Configuration

Output Units

Applies to output amplitude only

amplitude are volts peak-to-peak.

• Output units: Vpp, Vrms, or dBm. The default is Vpp.

• The unit setting is stored in volatile memory. The units are set to “Vpp”when power has been off or after a remote interface reset (provided the Pow er On state is set to “default”).

• The function generator uses the current units selection for both front panel and remote interface operations. For example, if you select “VRMS” from the remote interface, the units are displayed as “VRMS” on the front panel.

• The output units for amplitude cannot be set to dBm if the output termination is currently set to “high impedance”. The units are automatically converted to Vpp.

• Front-Panel Operation: Use the numeric keypad to enter the desired magnitude and then press th e approp ria te so ftk ey to s elect the unit s. You can also convert from one unit to another from the front panel. For example, to convert 2 Vpp to its equivalent value in Vrms, press and then press the V

707.1 mVrms for a sine wave.

• Remote Interface Operation:

. At power-on, the units for output

softkey. The converted value is

RMS

VOLTage:UNIT {VPP|VRMS|DBM}

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Chapter 3 Features and Functions

Output Configuration

Output Termination

Applies to output amplitude and offset voltage only. The Agilent 33220A has a fixed series output i mpedance of 50 o hms to the front-panel Output connector. If the actual load impedance is different than the value specified, the displayed amplitude and offset levels will be incorrect.

• Output termination: 1Ω to 10 kΩ, or Infinite. The default is 50Ω. The message line at the top of the display calls attention to output termination settings other than 50Ω.

• The output termination setting is stored in non-volatile memory and does not change when power has been off or after a remote interface reset (assuming the Power On state is set to “default”).

• If you sp eci f y a 50- o hm te r mination but ar e a ctu a l ly te r mi nat i n g i nt o an open circuit, the actual output will be twice the value specified. For example, if you set the offset to 100 mVdc (and specify a 50-ohm load) but are terminating the output into an open circuit, the actual offset will be 200 mVdc.

• If you change the output termination setting, the displayed output amplitude and offset levels are automatically adjusted (no error will be generated). For example, if you set the amplitude to 10 Vpp and then change the output termination from 50 ohms to “high impedance” , the ampli tu de displayed on the fun ct i on ge n erator’s front-pan el w ill to 50 ohms, the displayed amplitude will drop in half.

• You cannot specify the output amplitude in dBm if the output termination is currently set to “high impedance”. The units are automatically converted to Vpp.

• Front-Panel Operation: Press and select the Output Setup softkey. Then use the knob or numeric keypad to select the desired load impedance or press the Load softkey again to choose “High Z”.

• Remote Interface Operation:

OUTPut:LOAD {<ohms>|INFinity|MINimum|MAXimum}

double

to 20 Vpp. If you change from “high impedance”

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Chapter 3 Features and Functions

Output Configuration

Duty Cycle (Square Waves)

The duty cycle of a square wave represents the amount of time per cycle that the square wave is at a high level (assuming that the waveform is

not inverted).

20% Duty Cycle 80% Duty Cycle

(See Pulse Waveforms, on page 70 for information about duty cycle for pulse waveforms.)

• Duty Cycle: 20% to 80% (frequency < 40% to 60% (frequency > 10 MHz)

• The duty cycle is stored in volatile memory; the duty cycle is set to

50% (the default) when powe r has been o ff o r af te r a remot e inte rfac e reset (assuming the Power On state is set to “default”).

• The duty cycle setting is remembered when you change from square

wave to another function. When you return to the square function, the previous duty cycle is used.

• Limits Due to Frequency: If the square wave function is selected and

you change to a frequency that cannot produce the current duty cycle, the duty cycle is automatically adjusted to the maximum value for the new frequency. For example, if you currently have the duty cycle set to 70% and then change the frequency to 12 MHz, the function generator will automatically adjust the duty cycle to 60% (the upper limit for this frequency).

• The duty cycle setting does not apply to a square waveform used as

the modulating waveform for AM, FM, PM or PWM. A 50% duty cycle is always used for a modulating square waveform. The duty cycle setting applies only to a square waveform carrier.

• Front-Panel Operation: After selecting the square wave function,

press the Duty Cycle softkey. Then use the knob or numeric keypad to enter the desired duty cycle.

10 MHz)

Page 65

Chapter 3 Features and Functions

Output Configuration

• Remote Interface Operation:

FUNCtion:SQUare:DCYCle {<percent>|MINimum|MAXimum}

The APPLy command automatically sets the duty cycle to 50%.

Symmetry (Ramp Waves)

Applies to ramp waves only. Symmetry represents the amount of time per cycle that the ramp wave is rising (assuming that the waveform is not inverted).

0% Symmetry 100% Symmetry

• The symmetry is st ored in volatile memory; the symmetry is set to 100% (the default) when power has been off or after a remote interface reset (assuming the Power On state is set to “default”).

• The symmetry setting is remembered when you change from ramp wave to another function. When you return to the ramp function, the previous symmetry is used.

• If you select a ramp waveform as the modulating waveform for AM, FM, PM, or PWM, the symmetry setting does not apply.

• Front-Panel Operation: After selecting the ramp function, press the Symmetry softkey. Then use the knob or numeric keypad to enter the desired symmetry.

• Remote Interface Operation:

FUNCtion:RAMP:SYMMetry {<percent>|MINimum|MAXimum}

The APPLy command automatically sets the symmetry to 100%.

Page 66

Chapter 3 Features and Functions

Output Configuration

Voltage Autoranging

Autoranging is automatically selects the optimal settings for the output amplifier and attenuators. With autoranging disabled, the function generator uses the current

• You can disable autoranging to eliminate momentary disruptions

• Front-Panel Operation: Press and select the Output Setup

• Remote Interface Operation:

amplifier and attenuator settings.

caused by switching of the attenuators while changing amplitude.

However, turning autoranging off has side effects:

• The amplitude and offset accuracy and resolution (as well as waveform fidelity) may be adversely affected when reducing the amplitude below a range change that would occur with autoranging on.

• You may not be able to achieve the minimum amplitude that is available with autoranging on.

softkey. Then press the Range softkey again to toggle between the “Auto” and “Hold” selections.

VOLTage:RANGe:AUTO {OFF|ON|ONCE}

The APPLy command automatically enables autoranging.

enabled by default and the function generator

overrides the voltage autorange setting

and

Output Control

You can disable or enable the front-panel Output connector. By default, the output is disabled at power on to protect other equipment. When enabled, the key is illuminated.

• If an excessive external voltage is applied to the front-panel Output connector, an error message will be displayed and the output will be disabled.

Output

• Front-Panel Operation: Press to enable or disable the output.

To re-enable the output, remove the overload from the

connector

and press to enable the output.

Page 67

Chapter 3 Features and Functions

Inverted

Normal

Output Configuration

• Remote Interface Operation: OUTPut {OFF|ON}

The APPLy command overrides the current setting and automatically enables the Output connector.

Waveform Polarity

In the normal mode (default), the wa veform goes po sitive during the fi rst part of the cycle. In the inverted mode, the waveform goes negative during the first part of the cycle.

• As shown in the examples below, the waveform is inverted relative to

the offset voltage. Any offset voltage present will remai n unchanged when the waveform is inverted.

ormal

No Offset Voltage

Inverted

With Offset Voltage

Offset

• When a waveform is inverted, the Sync sign al asso ciat ed with the

waveform is not inverted.

• Front-Panel Operation: Press and select the Output Setup

softkey. Then press the Normal softkey again to toggle between the “Normal” and “Invert” selections.

• Remote Interface Operation: OUTPut:POLarity {NORMal|INVerted}

Page 68

Chapter 3 Features and Functions

Output Configuration

Sync Output Signal

A sync output is provided on t h e front-panel Sync connector. All of the standard output functions (except dc and noise) have an associated Sync signal. For certain applications where you may not want to output the Sync signal, you can disable the Sync connector.

• By default, the Sync signal is ro uted to the Sync connector (enabled). When the Sync signal is disabled, the output level on the Sync connector is at a logic “low” level.

When a waveform is in verted (see “W avefo rm P olarity” on the previous

• page), the Sync signal associated with the waveform is not inverted.

• The Sync signal setting is overridden by the setting of the marker used with the sweep mode (see page 103). Therefore, when is enabled (and the sweep mode is also enabl ed setting is ignored.

•For sine, ramp, and pulse waveforms, the Sync signal is a square waveform with a 50% duty cycle. The Sync signal is a TTL “high” when the waveform’s output is positive, relative to zero volts (or the dc offset value). The Sync signal is a TTL “low” when the output is negative, relative to zero volts (or the dc offset value).

•For square waveforms, the Sync signal is a square waveform with the same duty cycle as the main output. The Sync signal is a TTL “high” when the waveform’s output is positive, relative to zero volts (or the dc offset value). The Sync signal is a TTL “low” when the output is negative, relative to zero volts (or the dc offset value).

•For arbitrary waveforms, the Sync signal is a square waveform with a 50% duty cycle. The Sync signal is a TTL “high” when the first downloaded waveform point is output.

• For internally-modulated AM, FM, PM, and PWM, the Sync signal is referenced to the modulating waveform (not the carrier) and is a square waveform with a 50% duty cycle. The Sync signal is a TTL “high” during the first half of the modulating waveform.

), the Sync signal

the marker

• For externally-modulated AM, FM, PM, and PWM, the Sync signal is referenced to the carrier waveform (not the modulating waveform) and is a square waveform with a 50% duty cycle.

Page 69

Chapter 3 Features and Functions

Output Configuration

•For FSK, the Sync signal is referenced to the “hop” frequency. Sync signal is a TTL “high”

•For frequency sweeps with Marker Off, the Sync signal is a square waveform with a 50% duty cycle for the duration of the sweep. The Sync signal is a TTL “high” at “low” at the midpoin t of the sweep with the sweep, but is not literally equal to the sweep time because its timing includes the re-arm time.

•For frequency sweeps with Marker On, the Sync signal is a TTL “high” at the beginning of the sw eep and go es “l ow” at th e ma rker fre quency.

•For a triggered burst, the Sync signal is a TTL “high” when the burst

. The S ync sign al

begins number of cycles (may not be has an associated start phase). For an signal is the same as for a continuous waveform.

•For an externally-gated burst, the Sync signal follows the external gate signal. However, note that the signal will not go to a TTL “low” until the end of the last cycle (may not be the zero-crossing point if the waveform has an associated start phase).

• Front-Panel Operation: Press and select the Sync softkey again to toggle between “off” and “on”.

on the transition to the “ho p” frequency.

the beginning of the swe ep and goes

. The Sync signal is synchronized

is a TTL “low” at the end of the specified

the zero-crossing point if the waveform

infinite count burst

The

, the Sync

• Remote Interface Operation:

OUTPut:SYNC {OFF|ON}

Setting is stored in non-volatile memory

Page 70

Chapter 3 Features and Functions

Pulse Waveforms

A shown below, a pulse waveform consists of a period, a pulse width, a rising edge, and a falling edge.

90%

Pulse Width

10%

Rise Time

Period

90%

50%

10%

Fall Time

Pulse Period

• Pulse period: 200 ns to 2000 s. The default is 1 ms.

• The specified period must be greater than the sum of the pulse width and the edge time as shown below. The function generator will adjust the pulse width and edge time as needed to accommodate the specified period.

Period >

• Front-Panel Operation: After selecting the pulse function, press the Freq softkey again to toggle to the Period softkey. Then use the knob or numeric keypad to enter the desired pulse period.

Pulse Width + (1.6 X Edge Time)

• Remote Interface Operation:

PULSe:PERiod {<seconds>|MINimum|MAXimum}

Page 71

Chapter 3 Features and Functions

Pulse Waveforms

Pulse Width

The pulse width represents th e time from the 50% threshold of the rising edge of the pulse to the 50% threshold of the next falling edge.

Pulse width: 20 ns to 2000 s (see restrictions below).

• width is 100 µs.

•The minimum pulse width (Wmin) is affected by the period.

Wmin = 20 ns for period < Wmin = 200 ns for period > 10 s, but < Wmin = 2 µs for period > 100 s, but < Wmin = 20 µs for period > 1000 s.

• The specified pulse width must also be less than the difference between the period and the minimum pulse width as shown below. The function generator will adjust the pulse width as needed to accommodate the specified period.

Pulse Width <

• The specified pulse width must be less than the difference between the period and the edge time as shown below. The function generator will automatically adjust the pulse width as needed to accommodate the specified period.

Pulse Width <

• The pulse width must also be greater than the total time of one edge as shown below.

Period – Wmin

Period – (1.6 X Edge Time)

10 s.

100 s.

1000 s.

The default

pulse

Pulse Width >

• Front-Panel Operation: After selecting the pulse function, press the Width softkey. Then use th e knob or numeric keypad to enter the desired pu l se width.

• Remote Interface Operation:

FUNCtion:PULSe:WIDTh {<seconds>|MINimum|MAXimum}

1.6 X Edge Time

Page 72

Chapter 3 Features and Functions

Pulse Waveforms

Pulse Duty Cycle

The pulse duty cycle is defined as:

Duty Cycle = 100 X Pulse Width ÷ Period

where the pulse width represen ts the ti me from the 50% threshold of the rising edge of the pulse to the 50% threshold of the next falling edge.

• Pulse duty cycle: 0% to 100% (see restrictions below). The default is 10%.

• The specified pulse duty cycle must conform to the following restrictions determined by the minimum pulse width (Wmin). The function generator will adjust the pulse duty cycle as needed to accommodate the specified period.

Duty Cycle >

and

Duty Cycle <

where:

Wmin = 20 ns for period < Wmin = 200 ns for period > 10 s, but < Wmin = 2 µs for period > 100 s, but < Wmin = 20 µs for period > 1000 s.

• The specified pulse duty cycle must conform to the following restriction determined by the edge time. The function generator will adjust the pulse duty cycle as needed to accommodate the specified period.

Duty Cycle >

and

Duty Cycle <

• Front-Panel Operation: After selecting the pulse function, press the Dty Cyc softkey. Then use the knob or numeric keypad to enter the desired duty cycle.

• Remote Interface Operation:

100 X Wmin ÷ Period

100 X (1 – Wmin ÷ Period)

10 s.

100 s.

1000 s.

100 X (1.6 X Edge Time) ÷ Period

100 X (1 – (1.6 X Edge Time) ÷ Period)

FUNCtion:PULSe:DCYCle {<percent>|MINimum|MAXimum}

Page 73

Chapter 3 Features and Functions

Pulse Waveforms

Edge Time

The edge time sets each edge transition time (rising and falling) of the pulse. The rise time and fall time cannot be set independently—each is equal to the edge time. For each transition, the edge t ime represents the time from the 10% threshold to the 90% threshold.

• Edge time: 5 ns to 100 ns (see restrictions below). The default edge time is 5 ns.

• The specified edge time must fit within the specified pulse width as shown below. The function generator will adjust the edge time as needed to accommodate the specified pulse width.

Edge Time <

or in terms of duty cycle

Edge Time <

• Front-Panel Operation: After selecting the pulse function, press the Edge Time softkey. T hen use the knob or numeric k eypad to enter the desired edge time.

• Remote Interface Operation:

FUNCtion:PULSe:TRANsition {<seconds>|MINimum|MAXimum}

0.625 X Pulse Width

0.625 X Period X Duty Cycle ÷ 100

Page 74

Chapter 3 Features and Functions

Amplitude Modulation (AM)

A modulated waveform consists of a carrier waveform and a modulating waveform. In AM, the amplitude of the carrier is varied by the instantaneous voltage of the modulating waveform. The function generator will accept an internal or external modulation source.

For more information on the fundamentals of Amplitude Modulation, refer to chapter 7, “Tutorial”.

To Select AM Modulation

• The function generator will allow only one modulation mode to be enabled at a time. For example, you cannot enable AM and FM at the same time. When you enable AM, the previous modulation mode is turned off.

• The function generator will not allow AM to be enabled at the same time that sweep or burst is enabled. When you enable AM, the sweep or burst mode is turned off.

• Front-Panel Operation: You must enable AM before setting up any of the other modulation parameters. Press and then select “AM” using the Type softkey. The AM waveform is output using the present settings for the carrier frequency, modulating frequency, output amplitude, and offset voltage.

• Remote Interface Operation: To avoid multiple waveform changes, enable AM after you have set up the other modulation parameters.

AM:STATe {OFF|ON}

Page 75

Chapter 3 Features and Functions

Amplitude Modulation (AM)

Carrier Waveform Shape

• AM carrier shape: Sine, Square, Ramp, or Arbitrary waveform.

The default is Sine. You cannot use pulse, noise, or dc as the carrier waveform.

• Front-Panel Operation: Press any of the front-panel function keys except or . For arbitrary waveforms, press and then choose the Select Wform softkey to select the active waveform.

• Remote Interface Operation:

FUNCtion {SINusoid|SQUare|RAMP|USER}

You can also use the

APPLy

command to select the function, frequency

amplitude, and offset with a single command.

Carrier Frequency

The maximum carrier frequency depends on the function selected as shown below. The default is 1 kHz for all functions.

Function Minimum Frequency Maximum Frequency

Sine

Square

Ramp

Arbs

• Front-Panel Operation: To set the carrier frequency, press the Freq softkey for the selected function. Then use the knob or numeric keypad to enter the desired frequency.

• Remote Interface Operation:

FREQuency {<frequency>|MINimum|MAXimum}

1 µHz 1 µHz 1 µHz 1 µHz

20 MHz 20 MHz

200 kHz

6 MHz

You can also use the

APPLy

command to select the function, frequency

amplitude, and offset with a single command.

Page 76

Chapter 3 Features and Functions

Amplitude Modulation (AM)

Modulating Waveform Shape

The function generator will accept an internal or external modulation source for AM.

• Modulating waveform shape (internal source): Sine, Square, Ramp, Negative Ram p, Triangle, Noise , or Arb waveform.

• Square has 50% duty cycle.

• Ramp has 100% symmetry.

• Triangle has 50% sy m m e try .

• Negative ramp has 0% symmetry.

• You can use noise as the modulating waveshape, but you cannot use noise, pulse, or dc as the carrier waveform.

The default is Sine.

If you select an arbitrary waveform as the

• the waveform is automatically limited to 4K points. Extra waveform points are removed using decimation.

• Front-Panel Operation: After enabling AM, press the Shape softkey.

• Remote Interface Operation:

AM:INTernal:FUNCtion {SINusoid|SQUare|RAMP|NRAMp|

TRIangle|NOISe|USER}

modulating

waveshape

Modulating Waveform Frequency

The function generator will accept an internal or external modulation source for AM.

• Modulating frequency (internal source): 2 mHz to 20 kHz.

The default is 100 Hz

•

Front-Panel Operation

• Remote Interface Operation:

AM:INTernal:FREQuency {<frequency>|MINimum|MAXimum}

: After enabling AM, press the

AM Freq

softkey.

Page 77

Chapter 3 Features and Functions

Amplitude Modulation (AM)

Modulation Depth

The modulation depth is expressed as a percentage and represents the extent of the amplitude variation. At 0% depth, the output ampli tude is half of the selected value. A t 100% depth, the output amplitude equals the selected value.

• Modulation depth: 0% to 120%. The default is 100%.

• Note that even at greater than 100% depth, the function generator will not exceed ±5V peak on the output (into a 50Ω load).

•If you select the External modulating source, the carrier waveform is modulated with an external waveform. The modulation depth is controlled by the ±5V signal level present on the rear-panel Modulation In connector. Fo r example, if you have set th e modulatio n depth to 100%, then when the modulating signal is at +5 volts, the output will be at the maximum amplitude. When the modulating signal is at -5 volt s, then the outpu t will be at the

• Front-Panel Operation: After enabling AM, press the AM Depth softkey. Then use the knob or numeric keypad to enter the depth.

minimum

amplitu d e

• Remote Interface Operation:

AM:DEPTh {<depth in percent>|MINimum|MAXimum}

Page 78

Chapter 3 Features and Functions

Amplitude Modulation (AM)

Modulating Source

The function generator will accept an internal or external modulation source for AM.

• Modulating source: Internal or External. The default is Internal.

•

If you select the External source, the carrier waveform is modulated with an external waveform. The modulation depth is contro lled by the ±5V signal level present on the rear-panel Modulation In connector. For example, if you have set the modulation depth to 100% when the modulating signal is at +5 volts, the output will be at the

maximum

the output will be at the

Modulation

amplitude. When the modulating sign al is at -5 volts, then

minimum

+5 V

amplitude.

, then

-5 V

Front-Panel Operation

•

Remote Interface Operation

AM:SOURce {INTernal|EXTernal}

: After enabling AM, press the

Source

softkey.

Page 79

Chapter 3 Features and Functions

Frequency Modulation (FM)

A modulated waveform consists of a carrier waveform and a modulating waveform. In FM, the frequency of the carrier is varied by the instantaneous voltage of the modulating waveform.

For more information on the fundamentals of Frequency Modulation, refer to chapter 7, “Tutorial”.

To Select FM Modulation

• The function generator will allow only one modulation mode to be enabled at a time. For example, you cannot enable FM and AM at the same time. When you enable FM, the previous modulation mode is turned off.

• The function generator will not allow FM to be enabled at the same time that sweep or burst is enabled. When y ou enable FM, the sweep or burst mode is turned off.

• Front-Panel Operation: You must enable FM before setting up any of the other modulation parameters. Press and then select “FM” using the Type softkey. The FM waveform is output using the present settings for the carrier frequency, modulating frequency, output amplitude, and offset voltag e.

• Remote Interface Operation: To avoid multiple waveform changes, enable FM after you have set up the other modulation parameters.

FM:STATe {OFF|ON}

Page 80

Chapter 3 Features and Functions

Frequency Modulation (FM)

Carrier Waveform Shape

• FM carrier shape: Sine, Square, Ramp, or Arbitrary waveform.

The default is Sine. You cannot use pulse, noise, or dc as the carrier waveform.

• Front-Panel Operation: Press any of the front-panel function keys except or . For arbitrary waveforms, press and then choose the Select Wform softkey to select the active waveform.

• Remote Interface Operation:

FUNCtion {SINusoid|SQUare|RAMP|USER}

You can also use the amplitude, and offset with a single command.

APPLy

command to select the function, frequency

Page 81

Chapter 3 Features and Functions

Frequency Modulation (FM)

Carrier Frequency

The maximum carrier frequency depends on the function selected as shown below. The default is 1 kHz for all functions.

Function Minimum Frequency Maximum Frequency

Sine

Square

Ramp

Arbs

1 µHz 1 µHz 1 µHz 1 µHz

20 MHz 20 MHz

200 kHz

6 MHz

•The carrier frequency must always be greater than or equal to the frequency deviation. If you attempt to set the deviation to a value greater than the carrier frequency (with FM enabled), the function generator will automatically adjust the deviation to the maximum value allowed with the present carrier frequency.

• The sum of the carrier frequency and deviation must be less than or equal to the maximum frequency for the selected function

plus 100 kHz

(20.1 MHz for sine and square, 300 kHz for ramp, and 6.1 MHz for arbitrary waveforms). If you attempt to set the deviation to a value that is not valid, the function generator will automatically adjust it to the maximum value allowed with the present carrier frequency.

• Front-Panel Operation: To set the carrier frequency, press the Freq softkey for the selected function. Then use the knob or numeric keypad to enter the desired frequency.

• Remote Interface Operation:

FREQuency {<frequency>|MINimum|MAXimum}

You can also use the

APPLy

command to select the function, frequency

amplitude, and offset with a single command.

Page 82

Chapter 3 Features and Functions

Frequency Modulation (FM)

Modulating Waveform Shape

The function generator will accept an internal or external modulation source for FM.

• Modulating waveform shape (internal source): Sine, Square, Ramp, Negative Ram p, Triangle, Noise , or Arb waveform.

• Square has 50% duty cycle.

• Ramp has 100% symmetry.

• Triangle has 50% sy m m e try .

• Negative ramp has 0% symmetry.

• You can use noise as the modulating waveshape, but you cannot use noise, pulse, or dc as the carrier waveform.

The default is Sine.

If you select an arbitrary waveform as the

• the waveform is automatically limited to 4K points. Extra waveform points are removed using decimation.

• Front-Panel Operation: After enabling FM, press the Shape softkey.

• Remote Interface Operation:

FM:INTernal:FUNCtion {SINusoid|SQUare|RAMP|NRAMp|

TRIangle|NOISe|USER}

modulating

waveshape

Modulating Waveform Frequency

The function generator will accept an internal or external modulation source for FM.

• Modulating frequency (internal source): 2 mHz to 20 kHz.

The default is 10 Hz

•

Front-Panel Operation

•

Remote Interface Operation

FM:INTernal:FREQuency {<

: After enabling FM, press the

frequency

>|MINimum|MAXimum}

FM Freq

softkey.

Page 83

Chapter 3 Features and Functions

Frequency Modulation (FM)

Frequency Deviation

The frequency deviation setting represents the peak v ariation in frequency of the modulated waveform from the carrier frequency.

• Frequency deviation: 1 µHz to 10.05 MHz (limited to 150 kHz ramps and 3.05 MHz for arbitrary waveforms).

•The carrier frequency must always be greater than or equal to the deviation. If you attempt to set the deviation to a value greater than the carrier frequency (with FM enabled), the function generator will limit the deviation to the maximum value allowed with the present carrier frequency.

• The sum of the carrier frequency and deviation must be less than or equal to the maximum frequency for the selected function (20.1 MHz for sine and square, 300 kHz for ramp, and 6.1 MHz for arbitrary waveforms). If you attempt to set the deviation to a value that is not valid, the function generator will limit it to the maximum value allowed with the present carrier frequency.

•

Front-Panel Operation

Then use the knob or numeric keypad to enter the desired deviation.

• Remote Interface Operation:

FM:DEViation {<peak deviation in Hz>|MINimum|MAXimum}

: After enabling FM, press the

The default is 100 Hz.

plus 100 kHz

Freq Dev

for

softkey.

Page 84

Chapter 3 Features and Functions

Frequency Modulation (FM)

Modulating Source

The function generator will accept an internal or external modulation source for FM.

• Modulating source: Internal or External. The default is Internal.

•

If you select the External source, the carrier waveform is modulated with an external waveform. The frequency deviation is controlled by the ±5V signal level present on the rear-panel Modulation In connector. For example, if you have set the deviation to 100 kHz, then a +5V signal level corresponds to a 100 kHz increase in frequency Lower external signal levels produce less deviation and negative signal levels reduce the frequency below the carrier frequency.

Modulation

+5 V

-5 V

Front-Panel Operation

•

Remote Interface Operation

FM:SOURce {INTernal|EXTernal}

: After enabling FM, press the

Source

softkey.

Page 85

Chapter 3 Features and Functions

Phase Modulation (PM)

A modulated waveform consists of a carrier waveform and a modulating waveform. PM is very similar to FM, but in PM the phase of the modulated waveform is varied by the instantaneous voltage of the modulating waveform.

For more information on the fundamentals of Phase Modulation, refer to chapter 7, “Tutorial”.

To Select PM Modulation

• The function generator will allow only one modulation mode to be enabled at a time. For example, you cannot enable PM and AM at the same time. When you enable PM, the previous modulation mode is turned off.

• The function generator will not allow PM to be enabled at the same time that sweep or burst is enabled. When y ou enable PM, the sweep or burst mode is turned off.

• Front-Panel Operation: You must enable PM before setting up any of the other modulation parameters. Press and then select “PM” using the Type softkey. The PM waveform is output using the present settings for the carrier frequency, modulating frequency, output amplitude, and offset voltag e.

• Remote Interface Operation: To avoid multiple waveform changes, enable PM after you have set up the other modulation parameters.

PM:STATe {OFF|ON}

Page 86

Chapter 3 Features and Functions

Phase Modulation (PM)

Carrier Waveform Shape

• PM carrier shape: Sine, Square, Ramp, or Arbitrary waveform.

The default is Sine. You cannot use pulse, noise, or dc as the carrier waveform.

• Front-Panel Operation: Press any of the front-panel function keys except or . For arbitrary waveforms, press and then choose the Select Wform softkey to select the active waveform.

• Remote Interface Operation:

FUNCtion {SINusoid|SQUare|RAMP|USER}

You can also use the

APPLy

command to select the function, frequency

amplitude, and offset with a single command.

Carrier Frequenc y

The maximum carrier frequency depends on the function selected as shown below. The default is 1 kHz for all functions.

Function Minimum Frequency Maximum Frequency

Sine

Square

Ramp

Arbs

• Front-Panel Operation: To set the carrier frequency, press the Freq softkey for the selected function. Then use the knob or numeric keypad to enter th e des ir e d fr e qu e n c y.

• Remote Interface Operation:

FREQuency {<frequency>|MINimum|MAXimum}

1 µHz 1 µHz 1 µHz 1 µHz

20 MHz 20 MHz

200 kHz

6 MHz

You can also use the

APPLy

command to select the function, frequency

amplitude, and offset with a single command.

Page 87

Chapter 3 Features and Functions

Phase Modulation (PM)

Modulating Waveform Shape

The function generator will accept an internal or external modulation source for PM.

• Modulating waveform shape (internal source): Sine, Square, Ramp, Negative Ram p, Triangle, Noise , or Arb waveform.

• Square has 50% duty cycle.

• Ramp has 100% symmetry.

• Triangle has 50% sy m m e try .

• Negative ramp has 0% symmetry.

• You can use noise as the modulating waveshape, but you cannot use noise, pulse, or dc as the carrier waveform.

The default is Sine.

If you select an arbitrary waveform as the

• the waveform is automatically limited to 4K points. Extra waveform points are removed using decimation.

• Front-Panel Operation: After enabling PM, press the Shape softkey.

• Remote Interface Operation:

PM:INTernal:FUNCtion {SINusoid|SQUare|RAMP|NRAMp|

TRIangle|NOISe|USER}

modulating

waveshape

Modulating Waveform Frequency

The function generator will accept an internal or external modulation source for PM.

• Modulating frequency (internal source): 2 mHz to 20 kHz.

The default is 10 Hz

•

Front-Panel Operation

•

Remote Interface Operation

PM:INTernal:FREQuency {<

: After enabling PM, press the

frequency

>|MINimum|MAXimum}

PM Freq

softkey.

Page 88

Chapter 3 Features and Functions

Phase Modulation (PM)

Phase Deviation

The phase deviation setting repre sents the pe ak variat ion in phas e of the modulated waveform from the carrier wave form. The phase deviation can be set from 0 to 360 degrees. The default is 180 degrees.

•

Front-Panel Operation

softkey. Then use the knob or numeric keypad to enter the desired deviation.

• Remote Interface Operation:

: After enabling PM, press the

Phase Dev

PM:DEViation {< deviation in degrees>|MINimum|MAXimum}

Modulating Source

The function generator will accept an internal or external modulation source for PM.

• Modulating source: Internal or External. The default is Internal.

•

If you select the External source, the carrier waveform is modulated with an external waveform. The phase deviation is controlled by the ±5V signal level present on the rear-panel Modulation In connector. For example, if you hav e set the deviation to 180 degrees, signal level corresponds to a 180 degree phase shift. signal levels produce less deviation.

Modulation

•

Front-Panel Operation

: After enabling PM, press the

+5 V

-5 V

Lower external

then a +5V

Source

softkey.

•

Remote Interface Operation

PM:SOURce {INTernal|EXTernal}

Page 89

Chapter 3 Features and Functions

Frequency-Shift Keying (FSK) Modulation

You can configure the function generator to “shift” its output frequency between two preset values using FS K modulati on. The ra te at which the output shifts between the tw o freq uencies (cal led the “ca rrier freq ue ncy” and the “hop frequency”) is determined by the internal rate generator or the signal level on the rear-panel Trig In connector.

For more information on the fundamentals of FSK Modulation, refer to chapter 7, “Tutorial”.

To Select FSK Modulation

• The function generator will allow only one modulation mode to be enabled at same time turned off.

• The function generator will not allow FSK to be enabled at the same time that sweep or burst is enabled. When you enable FSK, the sweep or burst mode is turned off.

• Front-Panel Operation: You must enable FSK before setting up any of the other modulation parameters. Press and then select “FSK” using the Typ e softkey. The FSK waveform is output using the present settings for th e carrier frequency, output amplitude, and offset voltage.

• Remote Interface Operation: To avoid multiple waveform changes, enable FSK after you have set up the other modulation parameters.

FSKey:STATe {OFF|ON}

a time. For example, you cannot enable FSK and AM at the

. When you enable FSK, the previous modulation mode is

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Chapter 3 Features and Functions

Frequency-Shift Keying (FSK) Modulation

Carrier Waveform Shape

• FSK carrier shape: Sine, Square, Ramp, or Arbitrary waveform.

The default is Sine. You cannot use pulse, noise, or dc as the carrier waveform.

• Front-Panel Operation: Press any of the front-panel function keys except or . For arbitrary waveforms, press and then choose the Select Wform softkey to select the active waveform.

• Remote Interface Operation:

FUNCtion {SINusoid|SQUare|RAMP|USER}

You can also use the

APPLy

command to select the function, frequency

amplitude, and offset with a single command.

FSK Carrier Frequency

The maximum carrier frequency depends on the function selected as shown below. The default is 1 kHz for all functions.

Function Minimum Frequency Maximum Frequency

Sine

Square

Ramp

Arbs

•When the External source is selected, the output frequency is determined by the signal level on the rear-panel Trig In connector. When a logic low level is present, the carrier frequency is output. When a logic high level is present, the hop frequency is output.

• Front-Panel Operation: To set the carrier frequency, press the Freq softkey for the selected function. Then use the knob or numeric keypad to enter th e des ir e d fr e qu e n c y.

1 µHz 1 µHz 1 µHz 1 µHz

20 MHz 20 MHz

200 KHz

6 MHz

• Remote Interface Operation:

FREQuency {<frequency>|MINimum|MAXimum}

You can also use the

APPLy

command to select the function, frequency

amplitude, and offset with a single command.

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Chapter 3 Features and Functions

Frequency-Shift Keying (FSK) Modulation

FSK “Hop” Frequency

The maximum alternate (or “hop”) frequency depends on the function selected as shown below. The default is 100 Hz for all functions.

Function Minimum Frequency Maximum Frequency

Sine

Square

Ramp

Arbs

1 µHz 1 µHz 1 µHz 1 µHz

20 MHz 20 MHz

200 kHz

6 MHz

• The internal modulating waveform is a square wave with a 50% duty cycle.

• Front-Panel Operation: To set the “hop” frequency, press the Hop Freq softkey. Then use the knob or numeric keypad to enter the desired frequency.

• Remote Interface Operation:

FSKey:FREQuency {<frequency>|MINimum|MAXimum}

FSK Rate

The FSK rate is the rate at which the output frequency “shifts” between the carrier frequency and the hop freq uency when you se lect the in ternal FSK source.

•FSK rate (internal source): 2 mHz to 100 kHz. The default is 10 Hz.

• The FSK rate is ignored when the external FSK source is selected.

• Front-Panel Operation: To set the FSK rate, press the FSK Rate softkey. Then use the knob or nu meric ke ypad to en ter the desired rate

• Remote Interface Operation:

FSKey:INTernal:RATE {<rate in Hz>|MINimum|MAXimum}

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Chapter 3 Features and Functions

Frequency-Shift Keying (FSK) Modulation

FSK Source

• FSK source: Internal or External. The default is Internal.

•When the Internal source is selected, the rate at which the output frequency “shifts” between the carrier frequency and hop frequency is determined by the FSK rat e specified.

• The maximum external FSK rate is 100 kHz. Note that th e connector used for externally-con trolled FSK waveforms

• (Trig In) is not the same connector that is used for externallymodulated AM, FM, PM, and PWM waveforms (Modulation In). When used for FSK, the Trig In connector does not have adjustable edge polarity.

•

Front-Panel Operation:

• Remote Interface Operation:

FSKey:SOURce {INTernal|EXTernal}

After enabling FSK, press the

Source

softkey.

Page 93

Chapter 3 Features and Functions

Pulse Width Modulation (PWM)

In Pulse Width Modulation (PWM), the width of a pulse waveform is varied by the instantaneous voltage of the modulating waveform. The width of the pulse can be expre ssed e ither a s a pu lse width (expressed in time units, like the period) or a duty cycl e (expressed as a percentage of the period). The function generator will accept an internal or external modulation source.

For more information on the fundamentals of Pulse Width Modulation, refer to chapter 7, “Tutorial”.

To Select PWM Modulation

• The function generator only allows PWM to be selected for a pulse waveform, and PWM is the only modulation type supported for pulse.

• The funct ion g ener ator will not allo w PWM to be enab led at the same time that sweep or burst is enabled.

• Front-Panel Operation: You must enable PWM before setting up any of the other modulation parameters. Press to select pulse, and then press to turn on modulation. PWM is selected as the only modulation type supported for pulse. The PWM waveform is output using the present settings fo r the pulse frequency, modulating frequency, output amplitude, offset voltage, pulse width, and edge time.

• Remote Interface Operation: To avoid multiple waveform changes, enable PWM after you have set up the other modulation parameters.

PWM:STATe {OFF|ON}

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Chapter 3 Features and Functions

Pulse Width Modulation (PWM)

Pulse Waveform

• Pulse is the only waveform shape supported for PWM.

• Front-Panel Operation:Press .

• Remote Interface Operation:

FUNCtion {PULSe}

You can also use the amplitude, and offset with a single command.

APPLy

command to select the function, frequency

Pulse Period

The range for the pulse period is 200 ns to 2000 s. The default is 1 ms.

• Front-Panel Operation: After selecting the pulse function, press the Freq softkey again to toggle to the Period softkey. Then use the knob or numeric keypad to enter the desired pulse period.

• Remote Interface Operation:

PULSe:PERiod {<seconds>|MINimum|MAXimum}

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Chapter 3 Features and Functions

Pulse Width Modulation (PWM)

Modulating Waveform Shape

The function generator will accept an internal or external modulation source for PWM.

• Modulating waveform shape (internal source): Sine, Square, Ramp, Negative Ram p, Triangle, Noise , or Arb waveform.

• Square has 50% duty cycle.

• Ramp has 100% symmetry.

• Triangle has 50% sy m m e try .

• Negative ramp has 0% symmetry.

•

If you select an arbitrary waveform as the the waveform is automatically limited to 4K points. Extra waveform points are removed using decimation.

• Front-Panel Operation: After enabling PWM, press the Shape softkey.

modulating

The default is Sine.

waveshape

• Remote Interface Operation:

PWM:INTernal:FUNCtion {SINusoid|SQUare|RAMP|NRAMp|

TRIangle|NOISe|USER}

Modulating Waveform Frequency

The function generator will accept an internal or external modulation source for PWM.

• Modulating frequency (internal source): 2 mHz to 20 kHz.

The default is 10 Hz

•

Front-Panel Operation

softkey.

• Remote Interface Operation:

PWM:INTernal:FREQuency {<frequency>|MINimum|MAXimum}

: After enabling PWM, pre ss the

PWM Freq

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Chapter 3 Features and Functions

Pulse Width Modulation (PWM)

Width Deviation

The width deviation represents the variatio n in width (in seconds) in the modulated waveform from the width of the original pulse waveform.

• Width deviation: 0 s to 1000 s (see below).

• The width deviation cannot exceed the current pulse width.

• The width deviation is also limited by the minimum pulse width (Wmin):

Width Deviation < Pulse Width– Wmin

and

Width Deviation <

where:

Wmin = 20 ns for period < Wmin = 200 ns for period > 10 s, but < Wmin = 2 µs for period > 100 s, but < Wmin = 20 µs for period > 1000 s.

• The wi dth de vi at ion is limited by the current ed ge t im e setti n g.

Width Deviation < Pulse Width– (1.6 X Edge Time)

and

Width Deviation <

•

Front-Panel Operation

softkey. Then use the knob or numeric keypad to enter the desired deviation.

Period – Pulse Width – Wmin

10 s.

Period – Pulse Width – (1.6 X Edge Time)

: After enabling PWM, pre ss the

The default is 10 µs.

100 s.

1000 s.

Width Dev

• Remote Interface Operation:

PWM:DEViation {< deviation in seconds>|MINimum|MAXimum}

Note: The pulse width and width deviation, and the pulse duty cycle and duty cycle deviation are coupled in the front panel interface. If you select Width for the pulse waveform and enable PWM, the Width Dev softkey is available. On the other hand, if you select Dty Cyc for the pulse waveform and enable PWM, the Dty Cyc Dev softkey is available.

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Chapter 3 Features and Functions

Pulse Width Modulation (PWM)

Duty Cycle Deviation

The duty cycle deviation repres ents the variation in duty cycle of the modulated waveform from the duty cycle of the pulse waveform. The duty cycle deviation is expressed as a percentage of the period.

• Duty cycle deviation: 0 to 100% (see below). The default is 1%.

• The duty cycle deviation cannot exceed the current pulse duty cycle.

• The duty cycle deviation is also limited by the minimu m pulse width (Wmin):

Duty Cycle Deviation < Duty Cycle – 100 X Wmin ÷ Period

and

Duty Cycle Deviation <

where:

Wmin = 20 ns for period < Wmin = 200 ns for period > 10 s, but < Wmin = 2 µs for period > 100 s, but < Wmin = 20 µs for period > 1000 s.

• The duty cycle deviation is al so l imited by the current edge tim e setting.

Duty Cycle Dev < Duty Cycle – (160 X Edge Time) ÷ Period

and

Duty Cycle Dev <

•

Front-Panel Operation

softkey. Then use the knob or numeric keypad to ent er the desired deviation.

• Remote Interface Operation:

PWM:DEViation:DCYCle {< deviation in percent>|MIN|MAX}

100 – Duty Cycle – 100 X Wmin ÷ Peri od

10 s.

100 s.

1000 s.

100 – Duty Cycle – (160 X Edge Time) ÷ Period

: After enabling PWM, pre ss the

Dty CyC Dev

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Chapter 3 Features and Functions

Pulse Width Modulation (PWM)

Modulating Source

The function generator will accept an internal or external modulation source for PWM.

• Modulating source: Internal or External. The default is Internal.

•

If you select the External source, the pulse waveform is modulated with an external waveform. The width deviation or duty cycle deviation is controll ed by the ±5V signal level present on the rearpanel Modulation In connector. For example, if you have set the duty cycle to 10% and the duty cycle deviation to 5%, modulating signal is at +5 volts, the output will be at the duty cycle (15%). When the modulating signal is at -5 volts, the output will be at the

Modulation

minimum

duty cycle (5%).

+5 V

then when the

maximum

-5 V

Front-Panel Operation

• softkey.

Remote Interface Operation

•

PWM:SOURce {INTernal|EXTernal}

: After enabling PWM, pre ss the

Source

Page 99

Chapter 3 Features and Functions

Frequency Sweep

Frequency Sw eep

In the frequency sweep mode, the function generator “steps” from the start frequency to the stop frequency at a sweep rate which you specify. You can sweep up or down in frequency, and with either linear or logarithmic spacing. You can also configure the funct ion generator to output a single sweep (one pass from start frequency to stop frequency) by applying an external or manual trigger. The function generator can produce a frequency sweep for sine, square, ramp, or ar bitrary waveforms (pulse, noise, and dc are not allowed).

For more information on the fundamentals of a sweep, refer to chapter 7, “Tutorial”.

To Select Sweep

• The function generator will not allow the sweep mode to be enabled at the same time that burst or any modulation mode is enabled. When you enable sweep, the burst or modulation mode is turned off.

• Front-Panel Operation: You must enable swe ep before setti ng up a ny of the other sweep parameters. Press to output a sweep using the present settings for frequency, output amplitude, and offset.

• Remote Interface Operation: To avoid multiple waveform changes, enable the sweep mode after you have set up the other parameters.

SWEep:STATe {OFF|ON}

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Chapter 3 Features and Functions

Frequency Sweep

Start Frequency and Stop Frequency

The start frequency and stop frequency set the upper and lower frequ ency bounds for the sweep. The function generator begins at the start frequenc sweeps to the stop frequency, and then resets back to the start frequency.

• Start and Stop frequencies: ramps and 6 MHz for arbitrary waveforms). The sweep is phase continuous over the full frequency rang e. The default start frequency is 100 Hz. The default stop frequency is 1 kHz.

•To sweep up in frequency, set the start frequency < stop frequency. To sweep

•For sweeps with Marker Off, the Sync signal is a square waveform with a 50% duty cycle. The Sync signal is a TTL “high” at the beginning of the sweep a nd goes “low” at the midpoint of the sweep. The frequency of the sync waveform is equal to the specified sweep time. The signal is output from the front-panel Sync connector.

•For sweeps with Marker On, the Sync signal is a TTL “high” at the beginning of the sweep and goes “low” at the marker frequency. The signal is output from the front-panel Sync connector.

• Front-Panel Operation: After enabling sweeps, press the Start or Stop softkey. Then use the knob or numeric keypad to enter the desired frequency.

• Remote Interface Operation:

FREQuency:STARt {<frequency>|MINimum|MAXimum} FREQuency:STOP {<frequency>|MINimum|MAXimum}

down

in frequency, set the start frequency > stop frequency.

1 µHz to 20 MHz

(limited to 200 kHz for

100