Keithley 3930A Operator's Manual

Model 3930A

Multifunction Synthesizer

Operator’s Manual

Contains Operating and Servicing Information

WARRANTY

Keithley Instruments, Inc. warrants this product to be free from defects in material and workmanship for a period of 1 year from date of
shipment.

Keithley Instruments, Inc. warrants the following items for 90 days from the date of shipment: probes, cables, rechargeable batteries,
diskettes. and documentation.

During the warranty period, we will, at our option, either repair or replace any product that proves to be defective.

To exercise this warranty, write or call your local Keithley representative, or contact Keithley headquarters in Cleveland, Ohio. You will
he given prompt assistance and return instructions. Send the product, transportation prepaid, to the indicated service facility. Repairs
will be made and the product returned, transportation prepaid. Repaired or replaced products are warranted for the balance of the origi­nal warranty period, or at least 90 days.

LIMITATION OF WARRANTY

This warranty does not apply to defects resulting from product modification without Keithley’s express written consent, or misuse of
any product or pti. This warranty also does not apply lo fuses, software, non-rechargeable batteries, damage from battery leakage, or
problems arising from normal wear OI failure to follow instructions,

THIS WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSED OR IMPLIED, INCLUDING ANY IMPLIED
WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. THE REMEDIES PROVIDED HEREIN ARE
BUYER’S SOLE AND EXCLUSIVE REMEDIES.

NEITHER KEITHLEY INSTRUMENTS, INC. NOR ANY OF ITS EMPLOYEES SHALL BE LIABLE FOR ANY DIRECT, INDI­RECT, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OF ITS INSTRUMENTS AND
SOFTWARE EVEN IF KEITHLEY INSTRUMENTS, INC., HAS BEEN ADVISED IN ADVANCE OF THE POSSIBILITY OF
SUCH DAMAGES. SUCH EXCLUDED DAMAGES SHALL INCLUDE, BUT ARE NOT LIMITED TO: COSTS OF REMOVAL
AND INSTALLATION, LOSSES SUSTAINED AS THE RESULT OF INJURY TO ANY PERSON, OR DAMAGE TO PROPERTY.

Model 3930A Multifunction Synthesizer

Operator’s Manual

0 1991, Kcithlcy Instruments, Inc.

Test Instrumentation Group

All rights reserved.

Cleveland, Ohio, U.S.A.

August 1991, First Printing

Document Number: 3930A-900-01 Rev. A

All Keithley product names are trademarks or registered trademarks of Keithley Instruments, Inc.
Other brand and product names are trademarks or registered trademarks of their respective holders.

Safetv Precautions

The following safety precautions should be observed before using the Model 3930A Multifunction Synthesizer and any

associated instruments.

This instrument is intended for use by qualified personnel who recognize shock hazards and are familiar with the safety
precautions required to avoid possible injury. Read over this manual carefully before using the instrument.

Exercise extreme caution when a shock hazard is present at the te.st circuit. The American National Standards Institute

(ANSI) states that a shock hazard exists when voltage levels greater than 30V nns or 4.2.4V peak are present. A good

safety practice is to expect that hazardous voltage is present in any unknown circuit before measuring.

Inspect the connecting cables and test leads for possible wear, cracks, or breaks before each use.

For maximum safety, do not touch the test cables or any instruments while power is applied to the circuit under test.
Turn off the power and discharge any capacitors before connecting or disconnecting cables from the instrument.

Do not touch any object which could provide a current path to the commc~n side of the circuit under test or power line

(earth) ground. Always make measurements with dry hands while standing on a dry, insulated surface capable of with­standing the voltage being measured.

Instrumentation and accessories should not be connected to humans.

Table of Contents

SECTION 1 - General Information

1.1

1.2

1.3

1.4

1.5

1.6

1.6.1

1.6.2

1.6.3

1.6.4

1.7

1.8

INTRODUCTION .....................

FEATURES

..........................

WARRANTY INFORMATION ...........

MANUAL ADDENDA

SAFETY TERMS AND SYMBOLS .........

UNPACKING AND REPACKING

........

Unpacking

........................

shipment contents ..................

Operator’s Manual ..................

Repacking For Shipment ..............

OPTIONAL ACCESSORIES .............

SPECIFICATIONS ....................

SECTION 2 - Getting Started

2.1

2.2

2.2.1

2.2.2

2.3

2.3.1

2.3.2

2.3.3

2.4

2.5

2.5.1

2.5.2

2.5.3

INTRODUCTION

..................

INSTALLATION

..................

Installation Location ..............

Fan ...........................

LINE POWER SUPPLY ..............

LINE Voltage Selector Switch .......

Line Receptacle Connection .........

Line Fuse ......................

HANDLING PRECAUTIONS .........

BASIC OPERATION ................

Front Panel Summary .............

Typical Test Connections ..........

Operating Examples ..............

...........................

...........................

...........................

...........................

...........................

...........................

...........................

..........................

..........................

..........................

..........................

..........................

..........................

..........................

..........................

..........................

..........................

..........................

..........................

..........................

..........................

..........................

..........................

1-l
1-l
l-2
l-2
l-2
l-2
1-2
1-2
l-2
l-3

l-3
l-3

2-l
2-l
2-1
2-l
2-2
2-2
2-2
2-2

2-3
2-3
2-3
2-3
2-5

SECTION 3 - Operation

3.1

INTRODUCTION ..............................................................

3-l

3.2

FRONT PANEL AND REAR PANEL DESCRIPTION

...................................

3-l

3.2.1

Front Panel Description.

....................................................... 3-l

3.2.2

RearPanelDescription ........................................................

3-12

3.3

Input and Output Connections

.................................................... 3-13

3.3.1

InputConnections ...........................................................

3-13

3.3.2

outputConnections.. ........................................................

3-14

3.4

STARTUP

....................................................................

3-15

3.5

OPERATINGPROCEDURES

..................................................... 3-16

3.5.1

Setting Parameters Using Numeric Keys

...........................................

3-16

3.5.2

Setting Parameters using MODIFY .............................

3.5.3

ErrorCodes

..............................................

3.5.4

UnitsConversion ..........................................

3.5.5

Frequency Programming .....................................

3.5.6

Output Amplitude and Amplitude Modulation

....................

3.5.7

DC Offset Programming .....................................

3.5.8

Waveform Selection, Square-Wave Duty Cycle, and Synchronous Output

3.5.9

OscillationMode ...........................................

3.5.10

Trigger Parameters (Source, Rate, Burst Cycle, and Phase)

............

3.5.11

Frequency Sweep Operation ..................................

3.5.12

OutputRangeMode ........................................

SECTION 4 -

GPIB Interface

4.1

4.1.1

4.1.2

4.1.3

4.1.4

4.1.5

4.1.6

4.1.7

4.1.8

4.1.9

4.2

4.2.1

4.2.2

4.3

4.3.1

4.3.2

4.4

4.4.1

4.4.2

4.5

4.6

4.7

INTRODUCTION ..............................

GPIB Overview ..............................

Major GPIB Specifications ......................

Bus Line Signals and Operation ..................

GPIB Handshaking ...........................

Data Transfer Example ........................

Basic Talker Functions .........................

Basic Listener Functions .......................

Basic Controller Functions ......................

Multi-Line Interface Messages ...................

OVERVIEW OF MODEL 3930A GPIB INTERFACE

.....

Introduction ................................

Specifications __._ ._ __ ._ ._ _______ _._ __

MODEL 3930A PROGRAM CODES ................

Model 3930A Parameter-Setting Messages

..........

Model 3930A Inquiry Messages ..................

MODEL 3933A PHASE SHIFIIZR PROGRAM CODES.

..
Model 3933A Phase Shifter Parameter Setting Messages
Model 3933A Phase Shifter Inquiry Messages

.......

TYPICAL EXECUTION TIMES ....................

PROGRAM CODE SUMMARY TABLES

.............

SAMPLEPROGRAMS ..........................

4-l
4-l
4-l
4-2
4-2
43
4-3

4-3

4-4
44
4-6
4-6
4-6
4-10
4-10
4-21
4-26
4-26
4-32
4-35
4-38
4-43

List of Illustrations

SECTION 2 - Getting Started

Figure 2-l Front Panel Summary
Figure 2-2

TypicalConnections ..___.___...._._..._.._...___.........

SECTION 3 - Operation

Figure 3-1
Figure 3-2
Figure 3-3
Figure 34
Figure 3-5
Figure 3-6
Figure 3-7
Figure 3-8
Figure 3-9
Figure 3-10
Figure 3-11
Figure 3-12
Figure 3-13
Figure 3-14
Figure 3-15
Figure 3-16

Model 3930A Front Panel ...................................

Model 3930A Rear Panel ....................................

LogicInputCircuit ........................................

Amplitude Modulation Input Circuit .........................

Internal Trigger Output ...................................

SynchronousOutput ......................................

Sweep Marker and Sweep Synchronous Outputs .................

Relational Range for Allowed AC Amplitude Voltage and DC .......

Phase Relationship between Waveform and Synchronous Output ....

Burst Oscillation Mode Example .............................

Gate Oscillation Example Using Square Wave ...................

Gate Oscillation Example Showing Completion of Oscillation Cycle

Waveforms and Phase Definitions ............................

Relationship Between Sweep Frequency and Sweep Output ........

Output Resolution and Number of Digits for AC Only ............

Setting Resolution and Number of Digits for DC Only .............

SECTION 4 - GPIB Interface

Figure 4-l

Interface Connector
Figure 4-2 Handshake Timing Diagram
Figure 4-3 Data Transfer Example
Figure 44 Program Code Syntax
Figure 4-5 Response Output Format

Appendix A - Typical Data

Figure A-l Sine Wave Amplitude vs. Frequency Characteristics

A-2

Figure A-2 Total Harmonic Distortion vs. Frequency Characteristics

A-2

24
2-5

3-2
3-11
3-13
3-14
3-14
3-14
3-14
3-22
3-23
3-26
3-26
3-26
3-25
3-31

3.36
3-37

4-2
4-3
44
4-7
4-9

List of Tables

SECTION 2 - Getting Started

Table 2-l

FuseReplacement......................................................... 2-3

SECTION 4 - GPIB Interface

Table 4-l

Multi-lie Interface Messages ............................

Table 4-2

Interface Functions ....................................

Table 4-3

Bus Driver Specifications ...............................

Table 4-4

Response to Interface Messages ...........................

Table 4-5

StatusByte ..........................................

Table 4-6

Model 3930A Main Parameter Setting Messages ..............

Table 4-7

Model 3930A Trigger Parameter Setting Messages .............

Table 4-8 Model 3930A Sweep Parameter Setting Messages .............

Table 4-9 Model 3930A Miscellaneous Parameter Messages .............

Table 4-10 Parameter Messages Specific to Model 3930A GPIB ............

Table 4-11

Main Parameter Inquiry Messages ................................

Table 4-12

Model 3930A Trigger Parameter Inquiry Messages ....................

Table 4-13

Model 3930A Sweep Parameter Inquiry Messages .....................

Table 4-14 Model 3930A Miscellaneous Pammeter Inquiry Messages ...............

Table 4-15 Inquiry Messages for Parameters Specific to Model 3930A GPIB ..........

Table 4-16

Model 3933A Phase Shifter Main Parameter Setting Range ..............

Table 4-17

Model 3933A Phase Shifter Sweep Parameter Setting Messages ...........

Table 4-18

Model 3933A Phase Shifter Miscekmeous Parameter Setting Messages .....

Table 4-19

Parameter Setting Messages Specific to Model 3933A Phase Shifter Gl’IB ....

Table 4-20 Model 3933A Phase Shifter Main Parameter Inquiry Messages ............

Table 4-21 Model 3933A Phase Shifter Sweep Parameter Inquiry Messages ...........

Table 4-22 Model 3933A Phase Shifter Miscellaneous Parameter Inquiry Messages .....

Table 4-23 Inquiry Messages for Parameters Specific to Model 3933A Phase Shifter GPIB
Table 4-24

TypicalExecutionTimes ........................................

Table 4-25

Model 3930A Program Code Summary .............................

Table 4-26 Model 3933A Phase Shifter Program Code Summary ...................

4-5
4-6

4-6
4-7
4-11
4-12
4-14
4-16
4-19
4-20
4-21
4-22
4-23
4-24
4-25
4-26
4-28
4-30
4-31

4-32
4-33

4-33
4-34
4-35

4-38

441

SECTION 1

General Information

1.1 INTRODUCTION

The Model 3930A Multifunction Synthesizer can gener­a&frequencies between O.lmHz and l.?MHz. The Model
3930A can generate the entire frequency band at a resolu­tion of O.lmHz, with a high-frequency accuracy of
?5ppm.

Five AC waveforms, s, 2/, n , n , and \ are avai­able. Maximum output voltage for all waveforms is 30V
p-p/no load or 15Vp-p/5OQ load.

Since frequencies are synthesized directly by a custom
LSI digital IC, accuracy and stability are high, and the fre­quency switching time is short. Another advantage is the
continuity of phase at frequency switchover.

Frequency sweep, amplitude modulation (AM), burst os­cillation of up to 65,536 cycles, and gate oscillation are
available. The Model 3930A also employs a built-in trig­ger generator, and the square-wave duty cycle is also
variable. Combined with the optional Model 3933A
Phase Shifter, the Model 3930A forms a multiphase oscil­later.

The Model 3930A uses a two-line, 40-character liquid
crystal display to display selected functions, parameters,

and pertinent messages. Parameter settings are easily
made using both the numeric keys and the MODIFY
knob.

The Model 3930A is equipped with a standard GLIB
UEEE-488) interface and can be programmed over the
bus for the same operating modes and parameters that
can be controlled from the front panel.

1.2 FEATURES

l Wide bandwidth: O.lmHz to l.ZMHz (resolution:

O.lmHz).

l +5ppm frequency accuracy.
l Phase continuity at frequency switchover.
l Frequency can be set by period in addition to fre-

quency.

l Five AC waveforms available:

‘L,\,n,n,and\l

l The duty cycle can be set to values between 5% and

95% for frequencies up to 1OOkHz.

l High output: 30Vp-p/no load, 15Vp-p/5OQ load.
l AC output voltages can be set in p-p, rms, or dBV

units, and units conversion is also available.

.

AC voltage accuracy: M.5% K5OkHz, s ,3Vp-p or
greater).

l Low distortion: 0.1% or less (IOkHz to IOOkHz above

3OmVp-p, when output range is AUTO).

. Amplitude modulation of AC output waveforms by

an externally applied signal.

l-1

SECTION 1
General Information

DC offset and DC output voltages available: +15V/no
load, &7.5V/5OQ load.
Bust oscillation and gate oscillation modes:
Number of burst oscillation cycles: 1 cycle to 65,536 cy­cles.
Start/stop phase: -360’ to 360”.
Trigger source: External/internal and trailing/edge
are selectable.
Internal trigger period: lpsec to 2999.9sec.
A wide variety of frequency sweep functions and as­sociated input and output signals:

Sweep functions: 1, LIN/LOG, A / n
CONT/SINGLE and HOLD/RESUME sweep opera­tions.
Sweep time: 5msec to 9999s~~.
SYNC, MARKER, and X DlUVfZ output signals.
SINGL START and HOLD input signals.
Each parameter setting can be performed using either
the numeric keys or the MODIFY knob and keys. The
two-line, 40 character LCD clearly displays all neces-

sary information. Various modification steps sizes are
available: +l, ?5, x+2, and x+10.

Battery backed-up memory stores up 10 configuration

settings in addition to the configuration in effect when
power is turned off.
Standard GPIB interface allows the Model 3930A to be
programmed over the GPIB (IEEE-488 interface bus).
Digital I/O allows the Model 3930A to be used as a

multiphase oscillator in conjunction with the optional
Model 3933A Phase Shifter.
Output range mode can be switched from automatic

(AUTO) to fixed (D(D).

1.3 WARRANTY INFORMATION

Warranty information is located on the inside front cover

of this operator’s manual. Should your Model 393012 re­quire warranty service, contact the Keithley representa-

tive or authorized repair facility in your area for further

information. When returning the instrument for repair,

be sue to fill out and include the service form at the back

of this manual in order to provide the repair facility with
the necessary information.

1.4 MANUAL ADDENDA

Any improvements or changes concerning the ix&n­ment or manual will be explained in an addendum in­cluded with the unit. Be sure to note these changes and
incorporate them into the manual before using the unit.

1.5 SAFETY TERMS AND SYMBOLS

The following safety terms and symbols are found on the
instrument or used in this manuaL

The A

symbol on the instrument indicates that the

user should refer to the operating instructions.

The WARNING heading used in this manual explains

dangers that might result in personal injury or death. Al-

ways read the associated information very carefully be-

fore performing the indicated procedure.

The CAUTION heading used in this manual explains
hazards that could damage the instrument. Such damage
may invalidate the warranty.

1.6 UNPACKING AND REPACKING

1.6.1 Unpacking

After carefully unpacking the instrument from its ship­ping carton, inspect it for any obvious signs of physical
damage. Report any such damage to the shipping agent
immediately. Save the original packing carton for storage
or possible future shipment.

1.6.2 Shipment Contents

The following items are included with every Model
393OA order:

l Model 3930A Multifunction Synthesizer

. Model 3930A Operator’s Manual.
. Power cord

l Fuse (lA, 25OV, 5 x 20mm)
l BNC to BNC signal cable
l Additional accessories as ordered.

1.6.3 Operator’s Manual

If an additional manual is required, order the manual

package, Keithley part number 3930A-900.00. The man-

ualpackage includes an operator’s manual and anyperti-

nent addenda.

l-2

SECTION 1

General In,formation

1.6.4

Repacking For Shipment

Should it become necessary to return the Model 3930A
for repair, carefully pack the unit in its original packing
carton or the equivalent. Be sure to use a cardboard box of
sufficient strength if the original carton is not used.

Include the following information:

l Advise as to the warranty status of the instrument.
l Write ATTENTION REPAIR DEPARTMENT on the

shipping label.

l Filloutandincludetheserviceformlocatedattheback

of this manual.

1.7 OPTIONAL ACCESSORIES

The following accessories are available for use with the
Model 3930A.

Models 3900-l and 3900-Z Rack Mounting Kits: The
Model 3900-l mounts one Model 393OA in a standard 19
inch rack. The Model 3900-2 mounts two Model 3930As
side by side in a standard 19 inch rack. Both kits include
all necessary hardware for proper rack mounting of the
instruments.

Model 7007 Shielded IEEE-488 Cables: The Model
7007-l Urn, 3.3ft.j and Model 7007-Z (2m, 6.6ft.) can be
used to interface the Model 3930A to the IEEE488 bus.

Model 7051-Z BNC-to-BNC Cable: The Model 7051-Z is
SOL2 BNC to BNC cable (RG-580 2ft. (0.6m) in length.
The Model 7051-2 is terminated with male BNC connec­tors on both ends.

Model 7051-5 BNC-to-BNC Cable: The Model 7051-Z is
5OQ BNC to BNC cable (RG-58C) 5ft (1.2m) in length.
The Model 7051-5 is terminated with male BNC connec­tors on both ends.

Model7051-lOBNC-toBNCCable:TheModel7051-10is
similar to the Models 7051-2 and 7051-5 except that it is
loft. in length.

Model 7754-3 BNC-to-Alligator Cable: The Model
7754-3 is a 3ft. (O.Vm) 500 cable (RG-580, terminated
with a male BNC connector on one end and two alligator
clips on the other end.

Model 7755 5OQ Feed-through Terminator: The Model
7755 is a BNC to BNC adapter that is terminated with a
5OQ resistor. VSWR is ~1.1, DC to 250MHz.

1.8 SPECIFICATIONS

Detailed Model 3930A specifications may be found in
Appendix B.

l-3

SECTION 2

Getting Started

2.1 INTRODUCTION

This sections contains basic information on installation,
power line connections, and it also provides typical sim­ple operating examples.

2.2 INSTALLATION

The following paragraphs discuss Model 3930A installa­tion. In particular, use adequate care when installing the
unit. Improper installation will adversely affect the life,
reliability, and safety of the unit.

The Model 3930A weighs about 10 lbs; be careful when
carrying the unit or mounting it in a rack.

2.2.1

Installation Location

The allowable ambient temperature and humidity
ranges for the Model 3930A are.

operating: 0 to 4O”C, 10 to 9O%RH
storage: -10 to 5O”C, 10 to 8O%RH

Be sure to install the unit in a location that satisfies these
temperature and humidity conditions. Also the environ­ment must be free of dust and vibration, and the Model
3930A must not be exposed to direct sunlight.

The Model 3930A uses a line filter, but pulse noise or
strong magnetic or electric fields may cause incorrect op­eration of the unit. Do not install the unit near a source of
pulse noise or strong magnetic or electric fields.

The guard on the rear panel of the unit is designed to pro­tect rear panel connectors and should not be used as a leg
for installation. Do not stand the unit vertically on the
rear guard because it may fall over, causing instrument
damage or personal injury.

2.2.2 Fan

The Model 3930A is air-cooled by a fan. Insufficient air
flow may cause a component in the unit to fail. Follow the
instructions given below.

CAUTION
Observe the following precautions to pre­vent damage to the unit:

. An air intake port is provided on the rear

panel of the unit. Allow a space of at least

2-l

SECTION 2
Getting Started

four inches between the rear panel and a
wall or other obstruction.

l An exhaust port is provided on the bottom

panel of the unit. Install the unit on a rigid,
flat surface, and avoid installing it on soft
material such as a cushion. Be careful not to
insert foreign material between the bottom
of the unit and the surface underneath . An­other exhaust port is located on the top panel
of the unit. Be careful not to block the top
port by placing an object on top of the unit.

l Avoid mounting two or more units verti-

cally. Placing one unit on top of another will
obstruct the exhaust port.

l Dust collecting in the fan filter wilt prevent

sufficient air flow. In clean operating envi­ronments, wash the filter with a mild deter­gent every three months. When operating
the unit in a dusty environment, wash the fil­ter with a mild detergent at least once a
month.

l Immediately turn off the power to the unit if

the fan ceases to operate. Operating the in­strumentwiththefaninoperativemayresult
in damage to the instrument.

2.3 LINE POWER SUPPLY

The Model 3930A operates with a lOOV, 12OV, ZOV, or
24OV SO%, 48 to 62Hz, single-phase AC power supply.
The power consumption is 41VA.

2.3.1 LINE Voltage Selector Switch

TheLINEvoltageselectorswitchontherearpanelallows
you to change operating voltage of the power supply.
The standard setting of the switch is the same as the volt­age available in the country to which the unit is shipped.

To change the power supply voltage, first disconnect the
line cord, and set the supply voltage switch in the correct
position. Wait at least five seconds before turning the
power back on after hnning it off.

WARNING
Disconnect the power cord from the instrn­ment before changing the supply voltage
setting.

CAUTION
Be sure to set the line voltage switch to the
correct position for the line power voltage to
be used. Operating the instrument on an in­correctvoltagemaycausedamageto theunit.

2.3.2 Line Receptacle Connection

Connect the supplied power cord to the rear panel Line
receptacle and to a grounded AC power receptacle sup­plying the correct voltage.

WARNING
The Model 3930A is equipped with a 3-wire
power cord that contains a separate ground
wire and is designed to be used with
grounded outlets. When proper connections
are made, instrument chassis is connected to
the power line ground. If the AC outlet is not
grounded, the rear panel ground terminal

0

must be connected to safety earth

ground using #18AWG (or larger) wire be-

fore use.

2.3.3

Line Fuse

The line fuse, protects the instrument from over-current
situations. To replace the fuse, first disconnect the line
cord, and unscrew the fuse carrier from the fuse holder.
Replace the blown fuse only with the type listed in Table
2-1, then replace the fuse holder.

WARNING
Disconnect the line cord from the in&u­ment before replacing the fuse.

CAUTION
Use only a fuse of the rating listed in Table
2-1, or instrument damage may occur.

2-2

SECTION 2

Gettim Started

Table 2-1. Fuse Replacement

mi

NCSTE: Fuses are 5 x 20mm and have
25OV, normal blow ratings.

2.4 HANDLING PRECAUTIONS

A flat keyboard coated with a polyester film forms the
control panel surface of the Model 3930A. Be careful not
todamagethekeyboardsurfacebycuttingitwithasharp
instrument or touching it with a hot object.

When the panel or case becomes dirty, clean it with a soft

cloth.

If the panel or cake is too dirty for cleaning with a
dry cloth, dampen the cloth in mild detergent, and wipe
the panel or case with the damp cloth. Never use solvents

such as thinner or benzene, or chemical

dust

cloths to

avoid damaging the case or front panel surfaces.

2.5 BASIC OPERATION

The following paragraphs summarize front panel operat­ing controls, give typical test connections, and discuss
typical operating examples for the Model 3930A.

2.5.1 Front Panel Summary

Figure 2-l summarizes each front panel feature. For de­tailed information on each operating feature, refer to Sec­tion 3.

2.5.2 Typical Test Connections

Figure 2-2 shows typical tests comections behveen the
Mode13930A mainsynthesizerand a DLT. Note that SO<>
characteristic impedance cables such as the Model 7051
should be used for output connections.

2-3

SECTION 2
Getting Started

r

I

,

igure 2-l.

Front Panel Summary

2-4

SECTION2

Getting Started

‘igure

2-2.

Model 3930A

Typical Connections

FCTN

out

2.5.3 Operating Examples

The following examples give step-by-step instructions
for setting basic Model 3930A operating parameters. The
Model 3930A can be connected to an oscilloscope to view
the results of the various operating examples.

Example 1: Selecting the Waveform Type (Function)
The waveform type can be selected using the FCTN key

as follows:

1. Press FCTN and note that the instrument displays

the current function and the available functions.

2. Press the number key corresponding to the desired

function (O-51, or rotate the MODIFY knob until the
desired function number is displayed. For example,
press 3 to select the square-wave function. The
waveform will immediately change to the selected
function.

3. Press DSPL to return to the normal display mode.

Example 2: Setting fhe Waveform Frequency or Period
Use FREQ to set the frequency or period of the output

wavefoml as follows:

1. Press FREQ to enter the frequency-programming
mode. The instrument will display the allowable fre-

quency range (O.lmHz to 1.2MHz for sine waves,
O.lmHz to 1OOkHz for all other waveform types).

2. To directly enter a completely new numeric fre­quency value, key in the desired number followed
by the appropriate units key (Hz or kHz). For exam­ple, toenter afrequencyof lO.lkHz,press: 1 0. 1kHz.

3. To simply modify an existing frequency value, place
the cursor on the digit to be changed using 4 or .,
then use the MODIFY knob to set the digit to the de­sired value. Repeat as necessary for all digits to be
changed. Note that you can press the STEP SIZE key
to change the increment, or to multiply or divide by 2
or by 10.

4. To display the time period of the waveform fre­quency, press the set key. You can then key in a new
time period or modify the existing period, if desired.

5. Press Hz or kHz to return to frequency display.

6. Press DSPL to return to normal display.

Example 3: Setting the Output Amplitude
Use the AMFTD key to set the output voltage amplitude

as follows:

1. Press AMPTD, and note that the instrument displays
the current amplitude and allowed amplitude range.

2. To enter a completely new amplitude value in p-p
units, key in the numeric value, then press V or mV,
as required. For example, to enter a 30mV p-p ampli­tude, press: 3 0 mV.

3.

To simply modify the existing amplitude value, use
the cursor keys and the MODIFY knob to set the
value as required.

4. Press DSI’L to rehun to normal display.

2-5

SECTION 2
Getting Started

Example 4: Programming the DC Offset
The OFFSET key allows you to set the DC or average level

of the output waveform, as in the following example:

sweep parameters, while the SWEEP OPR keys control
sweep operation. Perform the steps below to demon­strate basic sweep operation:

1. Press OFFSET, and note that the instrument displays
the current offset value and allowed range.

2. Either key in the desired offset, or use the MODIFY
knob and cursor keys to change the value.

3. Press DSPL to return to normal display.

Example 5: Selecting the Operating Mode
The Model 3930A can be operated in continuous, burst,

or gate modes. The operating mode can be set with the
MODE key as in the following example:

1. Press MODE, and note that the instrument displays
the current mode and available modes (continuous,

burst, and gate).

2. Press the number of the desired mode (or rotate

MODIFY to choose the desired operating mode).

3. Press DSPL to return to normal display.

Example 6: Controlling Sweep Operation
The Model 3930A can be used to sweep across a desired

frequency range. The SWEEP keys allow you to program

Press START FREQ. and key in or use MODIFY to set
the sweep start frequency. For example, press 1 kHz
to program a 1kHz start frequency.
Press STOP FREQ. and set the sweep stop frequency
as desired. For example, to program a 1OkHz stop
frequency, press 10 kHz.
Press CTR and SPAN to view the center and span
frequencies. With 1kHz and IOkHz start and stop
frequencies, the center and span frequencies will be

5.5kHz and 9kHz respectively. NOTE: If you change
the center or span frequencies, the start and stop fre­quencies willbe automatically changed accordiigly.
Press SWEEP FCTN, and choose the type of sweep.
For example, press 2 to select a linear, ascending
sweep type.
Press SWEEP TIME, and program the sweep time as
required. For example, press 5 set to program a five­second sweep time.
To generate a single sweep, press SINGL START.
The unit will generate one sweep based on selected

sweep parameters.
To generate continuous sweeps, press SHIFT START
CONT. The Model 3930A will generate sweeps con­tinuously based on selected sweep parameters.
Press SWEEP OFF to stop a sweep.

2-6

SECTION 3

Operation

3.1 INTRODUCTION

This section contains detailed information on front panel
operation of the Model 3930A. For detailed GI’IB

(IEEE-488 bus) operation, refer to Section 4.

3.2 FRONT PANEL AND REAR PANEL
DESCRIPTION

3.2.1 Front Panel Description

The front panel of the Model 3930A is shown in
Figure3-1. The front panel is made up of a two-line,
40-character liquid crystal display and a control panel

with a built-in flat keyboard. The liquid crystal display
presents information useful for the operation of the
Model 3930A, such as the value of each parameter and
the range of permissible parameter values.

The keyboard includes a SHIFT key, which gives certain
other keys secondary functions. A key which is shaded
with the same color as the SHIFT key requires that you
press SHIFT first before accessing the function of that
particular key.

Most settings are maintained in battery backed-up mem­ory. As a result, the Model 3930A automatically assumes
the previous settings when the power is first turned on.

3-1

SECTION 3
Operation

Figure 3-l. Model 3930A Front Panel

3-2

SECTION 3

Oaemtion

Key Representations

This section uses special representation such as [SHIFT],

[MODIFY], or [SIZE] in the explanation of certain keys.

This representation indicates the following:

[SHIFT]

[MODIFY]

[MODIFYI [SIZE]

Press the applicable key after press­ing the SHIFT key to access the
shifted key function. The liquid crys­tal display indicates “SHIFT” in the
upper left caner when the Model
3930A is in the shift mode.

Key in the value using the DATA
keys, or change a given setting value
with the MODIFY knob. The up/
down step size when incrementing
or decrementing a value is fixed at 1,
and the cursor position is also fixed.

Key in the value using the DATA
keys, or change a given setting value
with the MODIF? knob. You can
specify the digit to be modified by
placing the cursor on the desired
digit using 4 orb. In addition, you
can change the modify up/down in­crement using the STEP SIZE key.

Detailed Descriptions

Each front panel feature is described below. The circled
number to the left of each description corresponds to the
appropriate number shown in Figure 3-1.

POWER ON/OFF @+xuer switch)
POWER controls AC power to the Model 3930A.

Press this switch mce to turn power on, and
press POWER a second time to turn power off.

w Display

­The two-line, 40-character display shows pa­rameter values and other important information
during operation. An active display also indi­cates that instrument power is turned on.

TRIG (Trigger keys

for

burst orgate oscillation)

The various TRIG keys are used for the burst or
gate oscillation modes. The bigger mode can be
programmed using the MODE key described be­1OW.

Press MAN to manually trigger the unit (the
MAN key is operational only in the external trig­ger mode). In the burst oscilLation mode, press­ing this key will generate the trigger signal. In
thegateoscillationmode, thegatesigmlremains
on as long as MAN is pressed.

When the external (EXT) bigger scarce is se­lected, MAN will be disabled under either of the
following conditions:

1. If % is the selected bigger scnme polarity,
and a low-level signal is applied to EXT TRIG
IN.

2. If5 is the selected trigger source, and a high­level signal is applied to EXT TRIG IN, or if
the BNC jack is left disconnected.

To use only the MAN key as the trigger signal,
select EXT i&L (external) for the trigger smnce
(SOURCE key), and disconnect the cable from
the EXT TRIG IN BNC connector.

SOURCE (Trigger sources
[MODIFY]

This key allows you to select the bigger source,
which includes EXT/INT (external/internal)
and % /$ (falling edge/rising edge). Selecting
EXT will enable front panel triggering through
the EXT TRIG IN BNC connector and the MAN
key. Selecting INT will enable the internal tigger
generator, the rate of which is programmed with
the INT RATE key.

In the gate oscillation mode, x and 4 come­spend togateonat fallingedgeandgateonatris­ing edge, respectively.

INT RATE Unternal trigger rate)
[MODIFY] [SIZE]

The INT RATE key sets the rate of the internal
trigger generator, which is enabled only for the
gate and burst oscillation modes when the inter­nal trigger swrce is selected.

The normal method of setting this parameter is
to program the rate as a time period, and the al-

3-3

SECTION 3
Operation

lowed rate ranges from 0.001msec (lpsec) to
2,999.9sec. You can also set the rate as a fre­quency, in which case the allowed frequency
range is from 0.0004Hz to lOOO.OkHz. When the
rate is programmed as a frequency, the actual
rate is set by rounding the reciprocal of the given
frequency to the value closest to the allowed pe­riod (the reciprocal is truncated to eliminate the
portion below the resoluiion). As a result, setting
the rate as a frequency may result in significant
errors when the reciprocal of the frequency is
very small. For example, entering frequencies of
either lOOO.OkHz or 6OO.OOkHz results in a
O.OOlmsec period.

BLJRST CYCLE (Number

of

burst cycles)

[MODIFY] KXZEI

The BURST CYCLE key allows you to program
the number of burst cycles, which defines the
number of waveform cycles generated in the
burst oscillation mode. The allowed range of set­tings is from 1 cycle to 65,536 cycles. To use burst
oscillation, select the burst oscillation mode with
the MODE key.

PHASE Wart/stop phase)
[MODIFY] [SIZE]

The PHASE key allows programming of the
start/stop phase setting for the burst or gate os­cillation modes. The allowed phase range is from

-360.0” to 360.0” with 0.1” resolution.
When the Model 3930A is used with the optional

Model 3933A Phase Shifter to form a multiphase
oscillator, the phase setting is the phase offset for
the Model 3933A.

NOTE
In the burst or gate oscillation modes, oscilla­tion may be unstable if the next trigger is ap­plied at approximately the same time the pre­vious oscillation cycle ends. In this situation,
set the Model 3930A temporarily to another
oscillation mode, then return it to the desired
mode. Doing so willrestorenormal operation.

SWEEP (Frequency sweep keys)

The various SWEEP keys are used to program
sweep functions such as start and stop fre­quency, center and span frequencies, and sweep

3-4

function and sweep time. The paragraphs below
summarize the operation of these keys. Refer to
the specifications located in Appendix B for de­tails on the sweep range.

Note that frequency parameters can also be set
using waveform period. See the discussion on

the ENTRY keys (

0

5

) for information on fre-

quency and period setting.

START FREQ (Start frequency)

[MODIFY] [SIZE1

The START FKEQ key allows you to set the start
frequency of the frequency sweep. You can spec­ify a start frequency that is either higher or lower
than the stop frequency. The relationship be­tween the start and stop frequency values deter­mines the sweep direction. If the start frequency
is higher than the stop frequency, the sweep will
be performed in a descending direction. If the
start frequency is lower than the stop frequency,
the sweep will be performed in the ascending di-

ECtiOll.

If the start frequency is changed, the sweep
range will be determined by the new start fre-

quency and the current stop frequency.

STOP FREQ (Stop frequency)

[MODIFY] [SIZE]

The STOP FREQ key allows you to set the stop
frequency of the frequency sweep. You can spec­ify a stop frequency that is either higher or lower
than the start frequency. If the stop frequency is
higher than the start frequency, the sweep will
be performed in ascending order. If the stop fre­quency is lower than the start frequency, the
sweep will be performed in descending order.

Ifthestopfrequencyischanged,thesweeprange
will be determined by the new stop frequency
and the current start frequency.

CTR (Center frequency)
[MODIFY] [SIZE]

The CTR key allows setting of the center fre­quency of the frequency sweep. The center fre­quency is specified as the center frequency for
the linear scale, and is not the sweep time basis
center frequency for LOG sweep.

SECTION 3

Oaeration

The relationship between the current start and

stop frequency values determines the sweep di-

rection.

If the

center

frequency is changed, the
start and stop frequencies will be changed, but
the span frequency will remain constant, and the
sweep direction will remain unchanged.

The CTR4 key substitutes the marker frequency
for the center frequency. The span frequency is
affected in the same manner as when using the
center frequency setting. If the substituted
marker frequency is different than the center fre­quency, the start and stop frequencies will
change accordingly.

SPAN (Frequency span)

[MODIFY] [SIZE]

This key allows you to set the frequency span of

the frequency sweep. The relationship between
the start and stop frequency values determines
the sweep direction. If the frequency span is
changed, the start and stop frequencies will be
changed so that the sweep range is determined

by the new frequency span and the current cen-

ter frequency, which will not change.

MKR (Markerfrequency)
[SHIFT], [MODIFY] [SIZE]

This key alkws you to set the marker frequency
of the frequency sweep. Note that you can spec­ify only one marker frequency. While the oscilla­tion frequency is higher than the programmed
marker frequency during a sweep, the marker
output signal available at the rear panel MKR
OUT jack will be set low. The marker output sig­nal will be set high at all other times.

SWEEP FCTN &ueep function)

[MODIFY]

The SWEEP FCTN key allows you to select the
sweep function. Available sweep functions in­clude: step (I,, linear triangular wave and saw-

toothwave (A cd 1, and log triangular wave

or sawtooth wave (A orA 1.

With the step sweep function, the output fre-

quency simply changes between the start fre­quency and stop frequency at intervals deter­mined by the sweep time. With the linear and log
functions, the frequency increases or decreases
linearly or logaxithmically, respectively.

SWEEP TIM!2 iSweep time)

[MODIFY] [SIZE]

The SWEEP TIME key allows you to set the
sweep time, which is the time period from the
start frequency to the stop frequency. The al­lowed sweep time range is from 5msec to
9,999sec. For log sweeps, the minimum sweep
time is 5.16msec per decade.

SWEEP OPR (Sweep Operation)

SlNGL START (Single start: singie-sweep

stortJ

This key starts a single sweep. Only one sweep

per key press will be generated.

CONT START (Continuous start: repeated sweep

start)

[SHIFT]

This key starts repeated sweeps, which will be

generated continuously until halted with the
HOLD or SWEEP OFF keys.

SWEEP OFF (Sweep ofl
SWEEP OFF cancels the sweep mode. The oscii-

lation frequency remains at the current fre­quency when this key is pressed, and the MKR
OUT, SWEEP SYNC OUT, and X DRIVE OUT
signals on the rear panel are set to high level,
high level and OV, respectively.

START STATE Gtart state:

start fre9uency

output)

This key resets the sweep and sets the output fre-

quency to the start frequency.
When START STATE is pressed, the MKR OUT

and SWEEP SYNC OUT signals on the rear pane1
are set high. The X DRIVE OUT signal is set to OV
when the start frequency is lower than the stop
frequency; the X DRIVE OUT signal is set to 1OV
when the start frequency is higher than the stop

3-5

SECTION 3

frequency. These signals can be used for scale ad-

justments of XY recorders.

STOP STATE (Stop frequency outputi

[SHIFT1

STOP STATE performs the opposite function of
the START STATE key in that it sets the output
frequency to the stop frequency.

When STOP STATE is pressed, the MKR OUT
and SWEEP SYNC OUT signals on the rear panel
are set high. The X DRIVE OLIT signal is set to OV
when the start frequency is higher than the stop
frequency; it is set to 1OV when the start fre­quency is lower than the stop frequency.

HOLD/RESM (Hold/resume: temporary sfop and
resume)

This key alternately stops and resumes the

SW-?+
Pressing HOLD/RESM while sweep is in pro-

gress will halt the sweep with the frequency,

MKR OUT, SWEEP SYNC OUT, and X DRIVE

OUT signals present at that time maintained at
their present values. Pressing HOLD/RESM
with the sweep halted resumes the sweep with
signal conditions previously present main­tained.

ENTRY (Main parameter setting keys)

FREQ &quency)

[MODIFY] [SIZE]
The FREQ key allows you to set the output fre-

quency of the unit. The allowed frequency range

is between O.OOOlHz and 1,ZOOkHz (l.ZMHz) for

the% and n

waveforms (with50% fixed duty

cycle); the range is from O.OOOlHz to 1OOkHz for
all other waveforms. Note that the 1OOkHz re­striction for the n waveform applies only with

a variable duty cycle; you can set the frequency
to amaximumof l,ZOOkHzwitha50% fixedduty
cycle. Also, you can set the frequency to a maxi-

mum of 1,ZOOkHz with the 2/ , /l , and \
waveforms if the quality of the waveform is un­important.

The oscillation frequency can be programmed in
frequency units or time period units. The al-

lowedrangeforperiodunitsisfrom0.00084msec
to lO,OOO.Osec (1,ZOOkHz limit) or from

0.01000msec to 10,000.0sec (100kHz limitation).
For period-based settings, the frequency is set to
the value of the reciprocal that is rounded to the
nearest number below O.lmHz. Therefore, pe­riod-based setting will cause significant errors
when the number of digits for the value of the re­ciprocal that is rounded is small. For example,
values of either lO,OOO.Osec or 6,000.OOsec will re-

sult in a frequency of O.OOOlHz.

If you press FREQ during sweep operation or
during sweep hold, the current frequency willbe
displayed, but you will not be able to change the
frequency.

Note that the phase of the waveform is continu­ous even when the frequency is changed.

AMFTD (Amplitude)

[MODIFY] [SIZE]

Pressing AMPTD allows you to set the output
amplitude of the unit. The allowed amplitude
when the DC offset is OV ranges from 0.3OmVp-p
to 3O.OOVp-p when the output range mode is set
to automatic (AUTO), or from OV to 3O.OOVp-p
when the output range mode is fixed (FXD).
When the DC offset is not OV, the upper and
lower limits are restricted (see specifications in
Appendix B). The values for the amplitude set­ting are for no-load (open) output conditions.

When the output range mode is AUTO, the am­plitude setting can be specified using rms or dBV
units in addition to using p-p units. You can
specify the appropriate units by pressing the ap­propriate ENTER units key when entering the
amplitude. Use mV or V for p-p values, mVrms
or Vrms for rms values, or dBV for dB values.

Note that p-p values are the only permissible
units for DC waveforms, and that the p-p value
varies from one waveform to another if you spec­ify the amplitude as an rms or dBV value. Also
note that the amplitude set by the AMPTD key is
the amplitude of an AC waveform. Set the ampli­tude of a DC waveform type with the OFFSET
key.

OFFSET (DC offseti
[MODIFY] [SIZE]

The OFFSET key enables DC offset voltage pro­gramming. The allowed offset is between -15V
and 15V for a DC waveform. For other waveform

SECTION 3

Operation

types, the offset range is restricted to the values
given in the specifications (Appendix B and
paragraph 3.5.7). All specified offset ranges are
for no-load (open-circuit) conditions.

FCTN (Function: waveformi

[MODIFY]

This key allows you to choose the output
waveform. Available waveforms include: DC,

SIN (sine wave), 2/ (triangular wave), L

(square wave), n (ascending sawtooth wave),

and\ (descending sawtooth wav4.
When the output range mode is AUTO, and the

waveform function is changed, the amplitude of

the new waveform is automatically changed to

p-p units, unless the new waveform is DC. For

details, refer to paragraph 3.5.8 in Section 3.

MODE (Oscillation mode)

[MODIFY]

The MODE key programs the oscillation mode

setting. Available oscillation modes include:
CONT (continuous oscillation), BRST (burst os­cillation), and GATE (gate oscillation). Refer to
paragraph 3.5.9 for details in Section 3.

DATA (iVumeric keys for parameter ent$
The DATA key set consists of numeric keys for

entering a value and ENTER (units) keys for set­ting the units of the entered value. The. (decimal
point) key and the +/- (sign inversion) key do

not affect parameters for which they have no

function.

Parameters that are selected with one numeric

character, such as waveform function and oscil-

lation mode, do not require that any ENTER key

be pressed. Such parameters are set simply by

entering one numeric character (or by rotating

the MODIFY knob as required).

For other parameters, enter the required value

with the numeric keys, then press the appropri-

ate ENTER units key. If you enter the incorrect

value, press the RUB OUT (delete) key. RUB

OUT deletes the numeric character or decimal
point from the rightmost position. To delete the
entire entered value and return the display to the

current value, press the original function key to
enable parameter entry for that function.

For frequency and amplitude where parameters
can be entered in different types of units, select
the appropriate units key from the ENTER keys
to complete entry of the value. Use the deg, %, or
cycle keys to enter phase, duty cycle, or burst cy­cles respectively.

The units keys also have a units-conversion
function. This feature is available for unit con­versions such as frequency-to-period conversion
for frequency, as well as amplitude p-p/m/
dBV conversions. When the units key is pressed
with the current setting displayed, the display
will be changed to reflect the newly-selected
units; note, however, that the actual output re­mains unchanged.

0 (Outpui range mode.,

~S~l,

[MODIFY1

Pressing SHIFI 0 enables output range mode se­lection and allows you to choose between auto­matic (AUTO) and fixed (FXD). For complete de-

tails on output range modes, refer to paragraph

3.5.12 in Section 3.

MODIFY (Modifij operation keys)
In addition to using the numeric keys, you can

set any parameter except the GPIB address, de­limiter, and memory number by using the MOD­IFY knob. The MODIFY knob is operational
when the Model 3930A is in the appropriate pa­rameter-entry mode, and the unit displays the
current parameter value.

MODIFY (Modify knob)
When the step size is +1 or ti, you can select the

digit to increase or decrease by 1 or by 5 by plac­ing the cursor under the appropriate digit (use4
or b ) and turning the MODIFY knob to the right

or left.

When the step size is x+2, you can divide the se-

lected parameter by 2 by turning knob counter­clockwise, or multiply the parameter by 2 by
turning the knob clockwise. Similarly, when the
step size is x+10, you can divide or multiply the
parameter by 10 by rotating the knob counter­clockwise or clockwise respectively. Note that

3-7

SECTIOhr 3

the cursor will not be displayed when the step
size is x+2 or x4.10.

This key moves the cursor to the left by one digit
each time it is pressed. Note that cursor will not
be displayed when the step size is x+2 or x+10.

This key mcwes the cursor to the right by one dig­it each time it is pressed. Note that cursorwilInot
be displayed when the step size is x+2 or x-10.

STEP SIZE W’IDOWN step size)
STEP SIZE changes the MODIFY knob UP/

DOWN step size. For parameters with values
that can be changed using variable step sizes, the
step size will change in the following order each
time this key is pressed: +I i5 x+2 x-10 ___

When the step size is j11 ori5, the digit indicated
by the flashing underline cursor changes by 1 or
by 5 when the MODIFY knob is rotated. When
the step size is x+2 or x+10, the cursor disap­pears, and the entire display value can be di­vided or multiplied by 2 or by 10 by rotating the
MODIFY knob.

Miscellaneous Keys

AM (Amplitude modulation)
[MODIFY]

The AM key allows you to turn amplitude
modulation on or off (l= on; O=off). Note that the
modulation signal is applied to the front panel
AMIN BNC jack. When the modulation signal is
OV, or when the modulation depth is 0%, turning
on amplitude modulation reduces the p-p ampli­tude of the output waveform to one-half its nor­mal value (the value when amplitide modula­tion is turned off). The output amplitude is the
normal, displayed amplitude value when the
modulation depth is 100%. Refer to paragraph

3.5.6 for more information.

r (Beep sound)

[MODIFY]
This key controls the beep that sounds when you

press front panel keys and when errors occur.
You can turn the beep OFF (0) or ON (1).

n DUTY (Squaw-wave duty cyclei

[MODIFY1 [SIZEI

The n DUTY key allows you to program the
square-wave duty cycle. The allowed duty cycle
ranges from 5.0% to 95.0%.

Two duty-cycle modes are available: 50% fixed

and variable. In the variable mode, the upper fre-

quency limit for square waves is restricted to

1OOkHz even if the duty cycle is set at 50%. Refer
to paragraph 3.5.8 for details.

FXD50 (Fixed 50% duty cycle)

IsKIm

This key fixes the square-wave duty cycle at 50%.
The upper frequency limit for square waves is

1.2MHz when the duty cycle is fixed at 50%. See
paragraph 3.5.8.

SHIFT

The SHIFT key adds a secondary function to
many other front panel keys. Those keys that
have shifted functions have those functions rep­resented on the lower part of each key using the
same color as the SHIFT key. Keys with shifted
functions in&de CTR 4 , MKR, GPIB, FXDSO,
and PRST.

When

the SHIFT key is first pressed, the unit en­ters the shift mode, and the liquid crystal display
indicates “SHIFT” in the upper left corner. The
shift mode is canceled when any key including
the SHIFT key is pressed (if a key with a shift
function is pressed, the unit enters that mode;
otherwise, it returns to the mode it was in before
SHIFT was pressed).

LOCAL (Return to locnl)
LOCAL cancels remote and returns the instru-

ment to thelocalmodewhenusedovertheGPIB.
When the instrument is in remote (as indicated

by “RMT” in the upper left comer of the display),

parameter setting is disabled, but you can still
display parameters by pressing appropriate
front panel keys.

3-8

SECTION 3

OptWi0n

GPIB (GPIB Address: GLIB address, delimiter)

[SHIFT]

The GPIB key allows you to program the GPIB

primary address and the output delimiter used

when the Model 3930A is acting as a GPIB talker.

Only the numeric keys can be used for setting
these parameters (the MODIFY knob cannot be
used). The allowed range for the primary ad­dress is from 0 to 30, and the delimiter can be se­lected for CR/LF or CR (CR and LF or CR only).

The GPIB primary address is the integer part of
this parameter, and the delimiter is defined by

the fractional part. For example, a parameter of

2.0 indicates a primary address of 2 and defines
CR/LF as the delimiter. Similarly, a parameter of

4.1 indicates a primary address of 4 with CR as
the delimiter.

To change only the primary address, enter only

the integer part of the number; the delimiter will
remain unchanged. To change only the delin­iter, enter the decimal point followed by the frac­tion (0 or 1); the primary address value will re­main unchanged.

When programming the primary address and/
or delimiter, remember that you must press any
one of the ENTER keys to complete the entry
process.

63

MEMORY (Memory operation keys)

­The MEMORY keys allow you to store and recall
instrument setups. Ten units of memory, num­bered 0 through 9, are available for setup storage.

ST0 (Store: store setup in

memoy)

The ST0 key stores the current instrument setup
parameters in the selected memory location

(O-9). You can use only numeric keys to store set­ups (the MODIFY knob cannot be used). l’ress­ing the numeric key will immediately store the
current parameter values and erase the previous
setup in the selected memory location.

RCL (Recall: wad setup from

,,WXOnJ)

RCL reads instrument setups from the desired
memory location (O-9). You can use only numeric
keys for selecting memory locations to recall (the
MODIFY knob cannot be used). Pressing the nu-

merit key will immediately read the contents of
the selected memory location and will change
the current instrument settings accordingly.

Refer to paragraph 3.512 for additional informa­tion on instrument settings after memory recall.

Additional Keys
LOCK (Lock out front panel keys)

This key allows you to disable parameter setting
via most front panel keys. Available modes are
ON (1) and OFF (0). When the lock is ON, the pa­rameters associated with most front panel keys
cannot be programmed, and the corresponding
operating modes cannot bc changed. Ho\ve\-cr.
LOCK, DSPL, and FCTX OUT O-S/OFF are still
operational when the lock is ON. In addition,

trigger input and sweep control input from ap-

propriate BNC connectors are still enabled.
current parameter values such as frequent); can

be displayed by pressing appropriate keys when

the lock is ON. The liquid crystal display Ivill in­dicate “LOCK” in the position where the modifi­cation step size is normally indicated. Also, pa­rameter names will not flash, and the cursor x\:ill

not be displayed.

PRST U%eset)

[SHIFT]
The PRST key recalls the factory default preset

operating parameters.Refer to the specifications

in Appendix B for a summary of preset parame-

ter settings.

DSPL (Main parameter display)

DSPL displays the followingmainparameters si-

multaneously: Signal output ON/OFF (blank for

ON), frequency, amplitude, amplitude modula-

tion mode (AM for on, blank for off), DC offset,

waveform function, oscillation mode, and sweep

mode (blank for normal oscillation). Note that

parameters cannot be programmed from the

main parameter display; you must press appro-

priate keys before setting parameters.

FCTN OUT ON/OFF 6ignni output ON/OFFI
FCTN OUT turns the output waveform off or on.

Each time this key is pressed, ON/OFF will tog­gle to the opposite state.

3-9

SECTION 3
Operation

0

When FCTN OUT is OFF, the main output signal
is turned off and open-circuited, but the SYNC
OUT signal is not affected and remains on.

The liquid crystal display indicates “OFF” in the
upper left cmner when the Model 3930A is in the
FCTN OUT OFF mode (except in the SHIFT or
REMOTE modes).

Note that the factory default setting for FCTN
OUT is ON at power on.

FCTN OUT (Function output:

wamfom

out-

put)
This BNC jack provides the waveform output
signal. The maximum output voltage range is
U5V/open circuit, and the output impedance is

5on.

SYNC OUT LSynchronous output)
This BNC jack provides a TTL-level square wave

signal at the same frequency as the main function
output waveform. Note that the duty cycle of
this signal is affected by the variable duty cycle

setting when the square-wave function is se­lected.

AM IN (Amplitude modulation input)
The BNC jack is used to apply an external ampli-

tude modulation signal. 100% modulation oc­curs with a flV input signal, and the input im­pedance is 1Ok.Q.

EXT TRIG IN (External-trigger input)
This BNC connector is an input for external TTL-

level signals, which can be used to trigger the
Model 3930A.

EXT TRIG IN is internally pulled up to a high
logic level, which means that the external trigger
input will remain hi h with no input signal con­netted. If the EXT $ trigger smxce is selected

with the unit in the gate oscillation mode, the

gate signal will be enabled, and the unit will ef­fectively be in the continuous oscillation mode
with no external trigger input signal applied.

3-10

SECTION 3

Operation

Figure 3-2.

Model 3930A Rear Panel

3-11