LeCroy LW110 User manual

User Manual
LW110/120
100 MS/s SINGLE / DUAL
ARBITRARY WAVEFORM GENERATOR
Publication No. 000904
700 Chestnut Ridge Road
Chestnut Ridge, NY 10977
TEL: [phone], FAX: [phone]
PUBLICATION DATE: September 4, 2000
REVISION: 1.0
Copyright 2000 by LeCroy. All rights reserved.This book or parts thereof may not be reproduced in any form
without written permission of the publisher.

WARRANTY STATEMENT
Products sold by LeCroy are warranted to be free from defects in workmanship or materials. LeCroy will, at its
option, either repair or replace any hardware products, which prove to be defective during the warranty period. You
are a valued customer. Our mission is to make any necessary repairs in a reliable and timely manner.
Duration of Warranty
The warranty period for this LeCroy hardware is three years, except software and firmware products designed for
use with LeCroy Hardware is warranted not to fail to execute its programming instructions due to defect in
materials or workmanship for a period of ninety (90) days from the date of delivery to the initial end user.
Return of Product
Authorization is required from LeCroy before you send your product for service or calibration. Call your nearest
LeCroy support facility. A list is located on the last page of this manual. If you are unsure where to call, contact
LeCroy Customer Support Department in Chestnut Ridge, U.S.A at (1) 914 578 6020 or via fax at (1) 914 578
5985.
Limitation of Warranty
LeCroy shall be released from all obligations under this warranty in the event repairs or modifications are made by
persons other than authorized LeCroy service personnel or without the written consent of LeCroy.
LeCroy expressly disclaims any liability to its customers, dealers and representatives and to users of its product,
and to any other person or persons, for special or consequential damages of any kind and from any cause
whatsoever arising out of or in any way connected with the manufacture, sale, handling, repair, maintenance,
replacement or use of said products.
Representations and warranties made by any person including dealers and representatives of LeCroy, which are
inconsistent or in conflict with the terms of this warranty (including but not limited to the limitations of the liability of
LeCroy as set forth above), shall not be binding upon LeCroy unless reduced to writing and approved by an officer
of LeCroy
Except as stated above, LeCroy makes no warranty, express or implied (either in fact or by operation of law),
statutory or otherwise; and except to the extent stated above, LeCroy shall have no liability under any warranty,
express or implied (either in fact or by operation of law), statutory or otherwise.
PROPRIETARY NOTICE
This document and the technical data herein disclosed, are proprietary to LeCroy, and shall not, without express written
permission of LeCroy, be used, in whole or in part to solicit quotations from a competitive source or used for manufacture by
anyone other than LeCroy. The information herein has been developed at private expense, and may only be used for operation
and maintenance reference purposes or for purposes of engineering evaluation and incorporation into technical specifications
and other documents, which specify procurement of products from LeCroy.

FOR YOUR SAFETY
Before undertaking any troubleshooting, maintenance or exploratory procedure, read carefully the
WARNINGS and CAUTION notices.
This equipment contains voltage hazardous to human life and safety, and is capable of inflicting
personal injury.
If this instrument is to be powered from the AC line (mains) through an autotransformer, ensure the
common connector is connected to the neutral (earth pole) of the power supply.
Before operating the unit, ensure the conductor (green wire) is connected to the ground (earth)
conductor of the power outlet. Do not use a two-conductor extension cord or a three-prong/two-prong
adapter. This will defeat the protective feature of the third conductor in the power cord.
Maintenance and calibration procedures sometimes call for operation of the unit with power applied
and protective covers removed. Read the procedures and heed warnings to avoid “live” circuits
points.
Before operation this instrument:
1. Ensure the instrument is configured to operate on the voltage at the power source. See Installation
Section.
2. Ensure the proper fuse is in place for the power source to operate.
3. Ensure all other devices connected to or in proximity to this instrument are properly grounded or
connected to the protective third-wire earth ground.
If the instrument:
- fails to operate satisfactorily
- shows visible damage
- has been stored under unfavorable conditions
- has sustained stress
Do not operate until performance is checked by qualified personnel.

This Page Intentionally Left Blank

Table of Contents
Chapter 1
GETTING STARTED
What’s In This Chapter ................................................................................................................................ 1-1
Introduction .............................................................................................................................................. 1-1
LW120 Feature Highlights ........................................................................................................................... 1-1
ArbExplorer Feature Highlights.................................................................................................................... 1-2
Description................................................................................................................................................... 1-4
Two Channels.......................................................................................................................................... 1-4
Output Functions ..................................................................................................................................... 1-4
Frequency................................................................................................................................................ 1-4
Amplitude................................................................................................................................................. 1-5
Trigger Modes.......................................................................................................................................... 1-5
Arbitrary Waveforms ................................................................................................................................ 1-5
Memory Segmentation............................................................................................................................. 1-5
Remote Control........................................................................................................................................ 1-5
Frequency Agility ..................................................................................................................................... 1-6
Options......................................................................................................................................................... 1-6
Safety Considerations.................................................................................................................................. 1-6
Supplied Accessories................................................................................................................................... 1-6
Specifications............................................................................................................................................... 1-7
Functional Description ................................................................................................................................. 1-7
Front Panel Connectors........................................................................................................................... 1-7
Channel 1 output................................................................................................................................. 1-7
Channel 2 Output ................................................................................................................................ 1-7
SYNC Output....................................................................................................................................... 1-7
Front Panel Indicators.............................................................................................................................. 1-7
Rear Panel Connectors ........................................................................................................................... 1-8
AM IN ................................................................................................................................................. 1-8
TRIG/FSK IN ....................................................................................................................................... 1-8
SCLK OUT .......................................................................................................................................... 1-9
SCLK IN .............................................................................................................................................. 1-9
SINE OUT ........................................................................................................................................... 1-9
REF IN................................................................................................................................................. 1-9
MASTER/SLAVE............................................................................................................................... 1-10
RS232 ............................................................................................................................................... 1-10
AC LINE ............................................................................................................................................ 1-10
AC FUSE........................................................................................................................................... 1-10
Operating Modes ................................................................................................................................... 1-10
Continuous Mode .............................................................................................................................. 1-11
Triggered Mode................................................................................................................................. 1-11
Gated Mode....................................................................................................................................... 1-11
Burst Mode........................................................................................................................................ 1-11
Frequency Agility ................................................................................................................................... 1-11

User Manual LW120
Sweep................................................................................................................................................1-11
FSK....................................................................................................................................................1-12
Ramped FSK .....................................................................................................................................1-12
FM......................................................................................................................................................1-12
Output Type............................................................................................................................................1-12
Standard Waveforms .........................................................................................................................1-12
Arbitrary (User) Waveforms ............................................................................................................... 1-13
Sequenced Waveforms .....................................................................................................................1-13
Output State.......................................................................................................................................1-15
Filters .................................................................................................................................................1-15
Programming The LW120 ......................................................................................................................1-15
Chapter 2
CONFIGURING The INSTRUMENT
Installation Overview ....................................................................................................................................2-1
Unpacking and Initial Inspection...................................................................................................................2-1
Safety Precautions .......................................................................................................................................2-1
Performance Checks....................................................................................................................................2-2
Power Requirements....................................................................................................................................2-2
Grounding Requirements .............................................................................................................................2-3
Long Term Storage or Repackaging For Shipment...................................................................................... 2-3
Preparation For Use.................................................................................................................................2-4
Logical Address Selection ............................................................................................................................2-4
Installation ....................................................................................................................................................2-4
Bench Operation ......................................................................................................................................2-4
Rack Mounting .........................................................................................................................................2-4
Chapter 3
USING The INSTRUMENT
Overview ......................................................................................................................................................3-1
Inter-Channel Dependency...........................................................................................................................3-1
Output Termination.......................................................................................................................................3-1
Input/Output Protection.....................................................................................................................................3-1
Power On/Reset Defaults .................................................................................................................................3-2
Controlling the LW120 ......................................................................................................................................3-4
Enabling the Outputs ........................................................................................................................................3-6
Selecting an Output Type .................................................................................................................................3-6
Changing the Frequency, Sample Clock and Channel 2 SCLK Divider ........................................................... 3-7
Programming the Amplitude and Offset............................................................................................................3-8
Selecting a Standard Function Shape ............................................................................................................3-10
Selecting an Operating Mode .........................................................................................................................3-13
Triggered Mode ..........................................................................................................................................3-13
Gated Mode................................................................................................................................................3-13
Burst Mode ................................................................................................................................................. 3-14
Arm Mode...................................................................................................................................................3-14
ii

User Manual LW120
Using the Manual Trigger........................................................................................................................... 3-16
Using the SYNC Output............................................................................................................................. 3-16
Selecting the Filter Type................................................................................................................................. 3-18
Selecting the SCLK Source and Reference ................................................................................................... 3-19
Modulating the Output .................................................................................................................................... 3-21
FM.............................................................................................................................................................. 3-21
Example 1, Modulating Standard Waveforms Using the Standard FM Mode ....................................... 3-23
Example 2, Modulating Standard Waveforms Using the Arbitrary FM Mode ........................................ 3-25
Frequency Modulating Arbitrary Waveforms ......................................................................................... 3-28
FSK............................................................................................................................................................ 3-28
Example 1, FSK Using Standard Waveforms........................................................................................ 3-30
Example 2, FSK Using Arbitrary Waveforms......................................................................................... 3-31
Ramped FSK ............................................................................................................................................. 3-32
Sweep........................................................................................................................................................ 3-33
Example 1, Generating Sweep Using Standard Waveforms................................................................. 3-35
Example 2, Generating Sweep Using Arbitrary Waveforms.................................................................. 3-37
AM.............................................................................................................................................................. 3-38
Adjusting Phase Offset Between Channels.................................................................................................... 3-39
Synchronizing Multiple Instruments................................................................................................................ 3-41
Saving and Recalling Setups ......................................................................................................................... 3-44
Generating Arbitrary Waveforms.................................................................................................................... 3-45
What Are Arbitrary Waveforms .................................................................................................................. 3-46
Using the Arbitrary Waveforms.................................................................................................................. 3-47
Generating Sequenced Waveforms ............................................................................................................... 3-48
What Are Sequenced Waveforms.............................................................................................................. 3-49
Changing Sequence Advance Modes........................................................................................................ 3-51
Chapter 4
REMOTE PROGRAMMING REFERENCE
What's in This Chapter................................................................................................................................. 4-1
Introduction to SCPI ......................................................................................................................................... 4-1
Command Format........................................................................................................................................ 4-2
Command Separator.................................................................................................................................... 4-2
The MIN and MAX Parameters.................................................................................................................... 4-3
Quering Parameter Setting .......................................................................................................................... 4-3
Quesry Response Format............................................................................................................................ 4-3
SCPI Command Terminator......................................................................................................................... 4-3
IEEE-STD-488.2 Common Commands ....................................................................................................... 4-3
SCPI Parameter Types................................................................................................................................ 4-4
Numeric Parameters................................................................................................................................ 4-4
Discrete Parameters................................................................................................................................ 4-4
Boolean Parameters................................................................................................................................ 4-4
Arbitrary Block Parameters...................................................................................................................... 4-4
Binary Block Parameters ......................................................................................................................... 4-5
SCPI Syntax and Styles............................................................................................................................... 4-5
iii

User Manual LW120
SOURce Subsystem.......................................................................................................................................4-12
OUTPut Subsystem ........................................................................................................................................4-33
FORMat Subsystem........................................................................................................................................4-36
INSTrument Subsystem..................................................................................................................................4-37
TRIGger Subsystem .......................................................................................................................................4-39
TRACe Subsystem .........................................................................................................................................4-43
Generating Arbitrary Waveforms................................................................................................................4-43
Arbitrary Memory Management..................................................................................................................4-43
Generating Sequenced Waveforms ...........................................................................................................4-49
Downloading Waveforms Using the DMA Port...........................................................................................4-54
Downloading FM Waveforms Using the DMA Port ....................................................................................4-55
Downloading Sequence Table Data Using the DMA Port .......................................................................... 4-56
SYSTem Subsystem.......................................................................................................................................4-57
IEEE-STD-488.2 Common Commands and Queries .....................................................................................4-59
The SCPI Status Registers ....................................................................................................................4-60
The Status Byte Register (STB).............................................................................................................4-61
Reading the Status Byte Register .........................................................................................................4-63
Clearing the Status Byte Register .........................................................................................................4-63
Service Request Enable Register (SRE) ..............................................................................................4-63
Standard Event Status Register (ESR) .................................................................................................. 4-64
Standard Event Status Enable Register (ESE) ......................................................................................4-65
Error Messages......................................................................................................................................4-66
Chapter 5
ArbExplorer
What's In This Chapter.................................................................................................................................5-1
Introduction to ArbExplorer ...............................................................................................................................5-1
Installing ArbExplorer ...................................................................................................................................5-2
Quitting ArbExplorer .....................................................................................................................................5-2
For the New and Advanced Users ...............................................................................................................5-2
Conventions Used in This manual................................................................................................................5-2
The opening Screen .....................................................................................................................................5-3
ArbExplorer Features ...................................................................................................................................5-5
The Control Panels.......................................................................................................................................5-5
The Main Panel ........................................................................................................................................5-7
Parameters ..........................................................................................................................................5-8
AM .......................................................................................................................................................5-8
Waveform ............................................................................................................................................5-8
Operating Modes .................................................................................................................................5-9
SYNC Output .......................................................................................................................................5-9
Output ..................................................................................................................................................5-9
iv

User Manual LW120
The Standard Waveforms Panel.............................................................................................................. 5-9
Channel 1&2........................................................................................................................................ 5-9
10 MHz Ref ....................................................................................................................................... 5-10
Frequency ......................................................................................................................................... 5-10
The Arbitrary & Sequence Panel ........................................................................................................... 5-11
Parameters........................................................................................................................................ 5-11
Sample Clock .................................................................................................................................... 5-12
10 MHz Ref ....................................................................................................................................... 5-13
Sequence Advance ........................................................................................................................... 5-13
Using the Segment Table ...................................................................................................................... 5-13
Using the Sequence table...................................................................................................................... 5-15
The Trigger Panel .................................................................................................................................. 5-17
Trigger Parameters ........................................................................................................................... 5-17
Slope ................................................................................................................................................. 5-18
Source............................................................................................................................................... 5-18
Arm.................................................................................................................................................... 5-18
The Modulation Panel............................................................................................................................ 5-19
Frequency Modulation....................................................................................................................... 5-19
FSK ................................................................................................................................................... 5-20
Sweep ............................................................................................................................................... 5-21
The Utility Panel..................................................................................................................................... 5-22
System Commands........................................................................................................................... 5-22
Filter .................................................................................................................................................. 5-22
Inter-Channel Control........................................................................................................................ 5-23
Multi-Instruments Sync Control ......................................................................................................... 5-24
The System and Command Editor............................................................................................................. 5-24
Communication...................................................................................................................................... 5-25
System Commands ............................................................................................................................... 5-26
Command Editor.................................................................................................................................... 5-26
The Waveform Composer.......................................................................................................................... 5-27
The Commands Bar............................................................................................................................... 5-28
File Commands ................................................................................................................................. 5-28
Edit Commands................................................................................................................................. 5-29
View Commands ............................................................................................................................... 5-30
Wave Commands.............................................................................................................................. 5-32
System Commands........................................................................................................................... 5-33
The Toolbar ........................................................................................................................................... 5-34
v

User Manual LW120
The Waveform Screen ...........................................................................................................................5-36
The Toolbar............................................................................................................................................5-34
The Waveform Screen ...........................................................................................................................5-36
The FM Composer......................................................................................................................................5-38
The Commands Bar ...............................................................................................................................5-38
File Commands.................................................................................................................................. 5-39
Wave Commands ..............................................................................................................................5-40
Generating Waveforms Using the Equation Editor.....................................................................................5-42
Parameters ........................................................................................................................................5-43
Level Adjuster ....................................................................................................................................5-43
Equation.............................................................................................................................................5-43
Control Buttons ..................................................................................................................................5-44
Writing Equations ...................................................................................................................................5-44
Equation Conventions ............................................................................................................................5-44
Typing Equations....................................................................................................................................5-45
Equation Samples ..................................................................................................................................5-46
Combining Waveforms...........................................................................................................................5-50
Appendix A
SPECIFICATIONS............................................................................................................................................A-1
vi

Chapter 1
GETTING STARTED
What’s In This
Chapter
This chapter contains a general description of the Model
LW110/LW120 Arbitrary Waveform Generator and an overall functional
description of the instrument. It lists and describes various options
available for this model. It also describes the front panel connectors
and indicators.
This manual provides description of all features and options available
with the instruments; however, some items described in the following
paragraphs and chapters may not be installed in your instrument. If you
purchased Model LW110, ignore all references in this manual to
Channel 2.
Introduction Model LW110 is a single-channel Arbitrary Waveform Generator. Model
LW120 is a dual-channel, Arbitrary Waveform Generator. It is a high
performance waveform generator that combines two separate and
powerful channels in one small package. Supplied free with the
instrument is ArbExplorer software, which is used for controlling the
LW120, generating, editing and downloading waveforms from a remote
computer. The following highlights the LW120 and ArbExplorer
features.
LW120 Feature
Highlights
•
•
•
•
•
•
•
•
•
•
Dual output configuration with Independent waveform control
Tight phase offset control between channels (1 point resolution)
14-bit vertical resolution
Nearly 19-bit offset resolution
4 Meg memory depth for each channel (optional)
Ultra fast waveform downloads using DMA
100 MS/s sample clock frequency
100 MHz sinewave output
1 ppm clock stability (option LNPC)
Extremely low phase noise carrier (option LNPC)

LW120 User Manual
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
External amplitude modulation
Frequency agility: FSK, ramped FSK, sweep, FM
Trigger start phase control and breakpoints
Built-in standard waveforms
Separate sequence generators for each channel
Multiple instrument synchronization with tight phase control
GPIB and RS232 links
!
50
TTL
POWER
I
0
OUTPUT
LeCroy
MODEL LW120
100 MS/s ARBITRARY WAVEFORM GENERATOR
!
50
CHAN 1 SYNC CHAN 2
RESET
CURSOR
MAN TRIG
TRIGGER
AMPLITUDEFREQUENCY UTILITYWAVEFORM
Figure 1-1, Model LW120
ArbExplorer
Feature
Highlights
Three powerful tools in one software package: Instrument control
panel, Waveform composer and FM signal composer
Detailed virtual front panels control all LW120 functions and modes
Wave composer generates, edits and downloads complex
waveforms
FM wave composer generates and downloads complex modulating
signals
Automatic detection of active instruments
Equation editor generates waveforms from equations
SCPI command and response editor simulates ATE operation
Translates waveform coordinates from ASCII and other formats
Simplifies generation of complex sequences
1-2 Getting Started

LW120 User Manual
Figure 1-2, ArbExplorer - Control Panels
Figure 1-3, ArbExplorer - Wave Composer
Getting Started 1-3

LW120 User Manual
Figure 1-4, ArbExplorer - FM Wave Composer
Description
Two Channels
Output Functions
Frequency
Detailed functional description is given following the general description
of the features, functions, and options available with the LW120.
The LW120 is a dual channel arbitrary waveform generator. Although
the two channels share a single sample clock source, each channel
can be controlled separately to generate different waveform, amplitude
and sequence. Having a single sample clock source is an advantage in
a dual-channel configuration because it allows tight control over inter-
channel synchronization and leading edge start phase where the initial
skew between the two channels is just a few nanoseconds.
Model LW120 is completely digital. There are no analog functions
resident in its hardware circuits. Data has to be downloaded to the
instrument for it to start generating waveforms. The instrument can
generate a few standard functions such as sine wave, triangular wave
and square wave. Each time that a standard function is required, the
instrument calculates its coordinates and places them in the waveform
memory. Therefore, every time a standard function is selected, minimal
time is required for the controller to compute the function and load its
data to the waveform memory.
Waveform frequency is programmed with 10 digits. Frequency
accuracy of the output waveform is determined by the clock reference.
The internal reference oscillator provides 100ppm accuracy and
1-4 Getting Started

LW120 User Manual
Amplitude
Trigger Modes
Arbitrary Waveforms
Memory Segmentation
Remote Control
stability over time and temperature. If higher accuracy and/or stability
are required, you may order the LW120 with 1ppm reference, or
connect an external frequency reference to the rear-panel reference
input connector.
The output level may be programmed separately for each channel
within from 20 mV to 20 Vp-p into an open circuit, or 10 mV to 10 V into
50Ω. Offset may be applied to the output to shift the signal either
positive or negative. Offset and amplitude are inter-related, so make
sure you understand the offset-amplitude ranges before you apply
offset to your signal. A special fine offset generator is built into each
channel, which allows programming of extremely small offset
increments (Available with option LNPC only). This feature extends the
offset resolution to 6 digits and is very useful in applications such as
mixer balancing where few micro-volts could sway the balance either
way.
Besides its normal continuous mode, the LW120 responds to a variety
of trigger sources. The output waveform may be gated, triggered, or
generate a counted burst of waveforms. A built-in trigger generator,
having a programmable period can be used as a replacement of an
external trigger source. The internal trigger generator can be
programmed with resolution of 7 digits.
The Model LW120 generates arbitrary waveforms with 14 bits of
vertical resolution. Any waveform it generates must first be downloaded
to waveform memory. The arbitrary waveform memory is a bank of 14-
bit words. Each word represents a point on the horizontal waveform
scale. Each word has a horizontal address that can range from 0 to
1,048,576 (4,191,280 with the 4 Meg option installed) and a vertical
address that can range from -8192 to +8191 (14 bits). Using a high
speed clocking circuit, the digital contents of the arbitrary waveform
memory are extracted and routed to the Digital to Analog Converter
(DAC). The DAC converts the digital data to an analog signal, and the
output amplifier completes the task by amplifying or attenuating the
signal at the output connector.
There is no need to use the complete memory every time an arbitrary
waveform is generated. Waveform memory can be divided into up to
4096 smaller segments and different waveforms can be loaded into
each segment. The various segments may then be loaded into a
sequence table to generate long and complex waveforms. The
sequence table can link up to 4096 segments, while each segment can
loop up to 1 million times.
The instrument must be used in conjunction with a host computer. All of
its functions, modes and parameters are fully programmable using
SCPI commands and syntax. There are three ways to program the
Model LW120, the first being low-level programming of each individual
parameter using SCPI commands. The second alternative is to use
ArbExplorer for high-level programming. ArbExplorer is a software
package supplied with the LW120 that simulates a mechanical front
Getting Started 1-5

LW120 User Manual
Frequency Agility
Multi-Instrumnet
Synchronization
panel. It has all the necessary push buttons, displays and dials to
operate the instrument as if you were using it on the bench. The third
alternative is using application specific drivers, such LabVIEW.
The LW120 must be programmed to generate waveforms. Therefore, it
is recommended that the user becomes familiar with its basic features,
functions and programming concepts as described in this and the
following chapters.
The instrument generates its sample clock from a DDS circuit (direct
digital synthesis). The DDS circuit enables frequency agility through the
complete frequency range of the LW120. Having such an enormous
range opens the door for a wide range of applications such as wide
band sweep, FSK and frequency modulation. The LW120 can generate
FSK, Ramped FSK and Linear or Logarithmic sweep. The instrument
can also frequency modulate its carrier using one of its built-in
waveforms, or with any user-defined modulating signal, which can be
downloaded using the FM wave composer.
There are applications requiring more than 2 synchronized channels, at
time even 10 channels. Synchronization between completely
independent, free-running instruments is not an easy task; Besides
distribution of the sample clock to all instruments, each instrument has
to be told when to start generating waveforms so that all start at the
same point and with the same phase. Triggering multiple instruments to
achieve synchronization is not enough because it will generate a jitter
of ±1 count. Multi-instrument synchronization is built into the LW120,
where special connectors and cables were designed to eliminate jitter
and to provide start phase control. There is not limit to the number of
LW120’s that can be daisy-chained, multiple instrument
synchronization is built into each instrument.
Options There are two options available with the LW120. The options can not
be retrofitted later. The LW120 must be ordered with the options
installed.
Option 4 Meg – The basic LW120 comes with 1 Meg memory. Option
4 Meg expands memory size to 4 Meg.
Option LNPC – This options adds the following: Low phase noise
source, 1ppm TCXO and high resolution offset adjustment
Safety
Considerations
The instrument has been manufactured according to international
safety standards. The instrument meets EN61010, VDE 0411/03.81
and UL 1244 standards for safety of commercial electronic measuring
and test equipment for instruments with an exposed metal chassis
that is directly connected to earth via the chassis power supply cable.
1-6 Getting Started

LW120 User Manual
WARNING
Do not remove instrument covers when operating or when
the power cord is connected to the mains.
Any adjustment, maintenance and repair of an opened, powered-on
instrument should be avoided as much as possible, but when
necessary, should be carried out only by a skilled person who is
aware of the hazard involved.
Supplied
Accessories
The instrument is supplied with an Instruction Manual. The manual
includes a disk with ArbExplorer for Windows 95/98/NT. Service
Manual and inter-instrument synchronization cables are available
upon request.
Specifications Instrument specifications are listed in Appendix A. These
specifications are the performance standards or limits against which
the instrument is tested. Specifications apply under the following
conditions: output terminated into 50Ωafter 30 minutes of warm up
time, and within a temperature range of 20oC to 30oC. Specifications
outside this range are degraded by 0.1% per oC.
Functional
Description
A detailed functional description is given in the following paragraphs.
The description is divided into logical groups: front and rear panel
connectors, operating modes, output type, output state, filters,
synchronization, and front panel indicators.
Front Panel
Connectors
The LW120 has 3 BNC connectors on its front panel: one main output
for each channel and one SYNC output. These connectors are
described below.
Channel 1 Output The channel 1 output connector outputs fixed (standard) waveforms
to 50 MHz, user (arbitrary) and sequenced waveforms with sampling
clock to 100 MS/s. Output impedance is 50Ω, that is, the cable
connected to this output should be terminated with 50Ω. Output
amplitude accuracy is calibrated when connected to a 50Ωload. The
output amplitude is doubled when the output impedance is above 1
MΩ.
Channel 2 Output The channel 2 output connector outputs fixed (standard) waveforms
to 50 MHz, user (arbitrary) and sequenced waveforms with sampling
clock to 100 MS/s. Output impedance is 50Ω, that is, the cable
connected to this output should be terminated with 50Ω. Output
Getting Started 1-7

LW120 User Manual
amplitude accuracy is calibrated when connected to a 50Ωload. The
output amplitude is doubled when the output impedance is above 1
MΩ.
SYNC Output The SYNC output generates a single TTL pulse for synchronizing
other instruments (i.e., an oscilloscope) to the output waveform. The
SYNC signal always appears at a fixed point relative to the waveform.
The location of the SYNC signal along the waveform is
programmable. The SYNC output is also used as marker output when
the sweep function is turned on.
Front Panel
Indicators
There are three LEDs on the front panel. When the output state is on,
the light illuminates. There are two LEDs, one for each channel and
one LED for the SYNC output.
Rear Panel
Connectors
The LW120 has a number of connectors on its rear panel. These
connectors are described below. Figure 1-5 shows rear panel plugs,
connectors and other parts.
!
SCLK INSCLK OUT REF IN RS232MASTER/SLAVE
FUSE
LINE
FRONT PANEL UTILITY MENU
CONFIGURE GPIB ADDRESS WITH
AM IN
TRIG/FSK IN
SINE OUT
CAUTION
NO OPERATOR SERVICABLE PARTS INSIDE
DO NOT REMOVE COVER
REFER SERVICING TO QUALIFIED PERSONNEL
WARNING
FOR CONTINUED PROTECTION AGAINST FIRE HAZARD
REPLACE FUSE WITH THE SAME TYPE AND RATING
DISCONNECT LINE CORD BEFORE REPLACING FUSE
!
IEEE std 488.2 PORT
AC VOLTAGE
85-265V
47-440Hz
40VA MAX
AUTOMATIC
SELECTION
'T' 0.5A/230V
MODEL/SERIAL # LABEL
Figure 1-5, Model LW120 – Rear Panel
1-8 Getting Started

LW120 User Manual
AM IN This input accepts signals that amplitude modulate channel 1, 2, or
both signal. The AM input becomes active only when the AM function
is selected otherwise, it has no effect on the output signal.
TRIG/FSK IN In general, this input accepts signals that stimulate generation of
output waveforms. The trigger input is inactive when the generator is
in continuous operating mode. When placed in trigger, gated or burst
mode, the trigger input is made active and waits for the right condition
to trigger the instrument. In trigger and burst modes, the trigger input
is edge sensitive, i.e., it senses transitions from high to low or from
low to high to trigger the LW120. The direction of the transition is
programmable. In gated mode, the trigger input is level sensitive, i.e.,
the generator is gated when the logic level is high and idle when the
level is logic low. Trigger level for this input is TTL.
The trigger input is common to both channels. Therefore, if the
LW120 is placed in trigger mode, both channels share the same
mode and the trigger input causes both channels to start generating
waveforms at the same time. Phase relationship between channels is
tightly controlled in trigger mode. You should expect both channels to
start generating waves with exactly the same start phase. Further
control of leading edge offset between channels is also provided.
The same input is used in FSK mode, where the output hops between
two frequencies – carrier and shifted frequencies. The output
generates carrier frequency when the FSK input is false and shifted
frequency when the FSK input is true.
The trigger input is also used as stop and start input when the LW120
is placed in Arm mode.
SCLK OUT This BNC connector outputs the programmed sample clock
frequency. Output level is ECL, terminated into 50Ωto –2V. Note that
correct termination is necessary for this output otherwise you will not
see this signal at all. This output generates sample clock waveforms
continuously, regardless if the LW120 is operating in continuous,
trigger, or gated modes.
The sample clock output is used for multiple-instruments
synchronization. In master mode, connect this output with a BNC to
BNC connector to the adjacent slave instrument. You may also use
this output to synchronize other components in your system to one
master clock.
SCLK IN This BNC connector accepts ECL level signal, terminated into 50Ωto
–2V. The external clock input is available for those applications
Getting Started 1-9

LW120 User Manual
requiring synchronization to one sample clock source. Normally, this
input is disabled. When enabled, the clock at this input replaces the
internal clock generator and the LW120 generates waveforms having
the external sample clock rate.
The sample clock output is also used for multiple-instruments
synchronization. In slave mode, connect this input with a BNC to BNC
connector to the adjacent master instrument.
SINE OUT This BNC connector outputs dc coupled, fixed level (1 Vpk-pk into 50Ω)
sine waveforms. This output is derived directly from the sample clock
generator and is active at all times, regardless of present operating
mode of the LW120. Therefore, the frequency of the sine output is
programmed using the sample clock parameter. Frequency agility and
modulation affect this output directly. The sine waveform output is
programmed to 100 MHz, so it may serve as an additional output to
those available on the front panel.
REF IN This BNC connector accepts 10 MHz, TTL level reference signal. The
external reference input is available for those applications requiring
better accuracy and stability reference than the one provided inside
the LW120. The reference input is active only after selecting the
external reference source mode.
MASTER/SLAVE This 9-pin “D” connector is used when connecting master to slave
units. The master/slave cable may be ordered separately from your
nearest LeCroy dealer. The master/slave mode must be activated
from the front panel otherwise, this connector and the cable attached
has no affect on normal operation of the LW120.
RS232 This 9-pin connector accepts standard RS232 cable. The LW120
operates at a fixed baud rate of 115K only. Connection and RS232
operation is explained later in this manual.
IEEE-488.2 PORT This 24-pin connector accepts standard GPIB cable. The GPIB
address is con figured using the front panel utility menu. The LW120
conforms to the IEEE-488.2 standard. Programming protocol is SCPI
version 1993.0. GPIB cables are available separately from your
LeCroy dealer.
AC LINE This 3-prong AC LINE connector accepts ac line voltage. The LW120
senses the line voltage and sets the appropriate range automatically.
Therefore, traditional line voltage selector is not available on the rear
panel. To avoid potentially hazardous situations, always connect the
center pin to mains ground using the line cord that is supplied with the
1-10 Getting Started