LeCroy 9400A User Manual

THE LeCROY MODEL 9400A

DIGITAL OSCILLOSCOPE

North American Headquarters:

LeCROY Corporation

700 Chestnut Ridge Road

Chestnut Ridge, NY 10977-6499
U.S.A.

Tel: [phone]

Serial Number

January 1990

European Headquarters:

LeCROY S.A.
2, rue Pr~-de-la-Fontaine

Case postale 341
1217 Meyrin 1 / Geneva
Switzerland
Tel: [phone]

TABLE OF CONTENTS

Section

I. GENERAL INFORMATION

Technical Data Sheet

1.1

1.2

1.3

1.4

1.5

1.6

2. PRODUCT DESCRIPTION

2.1

2.2

2.3

2.4

2.5

2.6

2.7

3. INSTALLATION

Warranty
Assistance and Maintenance Agreements
Documentation Discrepancies

Service Procedure
Return Procedure

Initial Inspection

Introduction
9400A Architecture

ADCs and Memories
Trigger

Automatic Calibration

Display
Manual and Programmed Control

Page Number

I-I
i-I

1-2
1-2

1-2
1-3

2-1

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

3.1

3.2

3.3

DISPLAY LAYOUT

4.

4.1

4.2

4.3

4.4

4.5

4.6

5. MANUAL OPERATION

5.1 Front-panel Controls

5.1.1 Vertical

5.1.2

5.1.3 Trigger

5.1.4 Displaying Traces

5.1.5 Display Control

5.1.6 Screen Adjustments

5.1.7 Cursors

Safety Information
Operating Voltage
Switching on the 9400A

Menu Field
Time and Frequency Field

Trigger Delay Field
Abridged Front Panel Status Field
Displayed Trace Field
Message Field

Time Base

3-1
3-1
3-2

4-1
4-2

4-2
4-2
4-2

4-3

5-1

5-1
5-4

5-6
5-12
5-12
5-1

5-15

ii

5.2 Menu Controls

5-18

5.2.1

5.2.2

5.2.3

5.2.4

5.2.5

5.2.5.1

5.2.5.2

5.2.6

5.2.7

6. REAR PANEL CONTROLS AND CONNECTORS

6.1

6.2

6.3

6.4

6.5

REMOTE OPERATIONS

7.

7.1

7.2

7.3

7.4

Store Menu
Panel Status Menu

Memory Status
Storage and Recall of Front Panel Setups
Special Modes

Auto-store Mode

Common Expand Mode

RS-232-C Setup
Plotter Setup

Fuse Protection
Accessory Power Connectors
Battery Pack
GPIB and RS-232-C Port Selection
Plotter Connector

Programmed Control
RS-232-C Ports

GPIB Port (Option OP02 only)
C~IB and RS-232-C Command Format

5-18
5-20
5-22

5-24
5-25
5-25
5-26

5-26
5-28

6-1
6-1
6-1
6-1

6-2

7-1
7-1

7-2
7-3

7.4.1

7.4.2

7.4.3

7.4.4

7.4.5

7.4.6

7.4.7

7.4.8

7.4.9

7.5

7.6

7.6.1

7.6.2

7.6.3

7.6.4

7.6.5

7.6.6

7.6.7

7.6.8

7.6.9

7.6.10

Introduction

Compound Commands
Command Format

Answers from the 9400A

Flushing of 9400A Output Buffer

Command Synchronization with Data Acquisition

Character Strings
Prompt
Errors and Adapted Values

Data Block Transfers

Commands

Notation
Acquisition Parameter Commands

Display Commands
Plotter Commands

Transfer Commands
Other Remote Commands
Communication Format Command

Status Byte and Mask Register Commands
GPIB Interface Message Interpretation
RS-232-C Only Commands

7-3
7-4

7-4
7-5

7-6
7-6

7-7
7-7
7-8

7-8
7-11

7-11

7-12
7-15
7-20
7-22
7-30
7-31
7-34
7-38

7-39

iii

7.7

7.8

7.9

7.10

Binary Format of Waveform Descriptors
Format of Trigger Time(s)

Data Addressing Conventions

Interpretation of Waveform Data Values

7-43
7-47
7-48
7-50

7.10.1

7.10.2

7.11

7.11.1

7.11.2

Waveform Data in 8-bit Format
Waveform Data in 16-bit Format

Use of the Service Request (SRQ) Interrupts

Service Request in GPIB
Service Request in RS-232-C

8. BASIC 9400A WAVEFORM MEASUREMENTS AND OPERATING PROCEDURES

8.1

8.2

8.3

8.4

Repetitive Signal Acquisition

Single Shot Acquisition
Trace Expansion - Expand A/B
Sequential Recording of Single Events in

Segmented Memory

8.5

8.6

8.7

8.8

8.9

8.10

8.11

8.12

8.13

8.14

Slow Signal Recording
Window Triggering
Storing and Recalling Front Panel Setups
Signal Storage in Memories C, D
Redefinition Function - Expand Memories C, D
Auto-Store in Memory C, D
Common Expand Mode

Remote Control Via RS-232-C Port
Remote Control Via GPIB (Option OP02 Only)

Making a Plot when the Computer, the 9400A,
and the Plotter are All Connected Together
on a GPIB Bus (Option OP02 Only)

8.15

Configuring the Parallel Polling (Option 0P02 0nly) 8-20

7-50
7-52
7-52

7-52
7-55

8-1
8-3

8-5

8-6
8-8
8-9
8-9
8-10

8-11
8-12
8-13
8-14
8-18

8-19

GETTING THE MOST OUT OF YOUR 9400A

9.

9.1

9.2

9.3

9.4

WPOI WAVEFORM PROCESSING OPTION

I0.

I0.i

10.2

Front Panel Controls

Accurate Amplitude Measurements
Accurate Time Measurements
Auto-calibration

Processing Capabilities
Setting up a Waveform Processing Function
Manually

10.2.1

10.2.2

10.2.3

10.2.4

10.2.5

10.2.6

Summed Average
Continuous Average
Extrema

Arithmetic

Functions
Smoothing

9-1
9-1
9-3
9-4

I0-i
10-2

10-3
10-4
10-5
10-6
10-6
10-6

iv

10.3

10.4

10.5

10.6

Remote Control of Waveform Processing Functions
Additional Values in the Descriptors of

Processed Waveforms

Vertical Scaling Units

Index of Topics

10-8

10-13
10-15
10-17

11.

Fast Fourier Waveform Processing Option

(WP02, V 2.06FT)

ii.i

11.2

11.3

11.4

11.4.1

11.4.2

11.5 FFT Application Hints

11.5.1

11.5.2

11.5.3

11.6

11.7

11.8

11.9
ii. I0

Processing Capabilities
Modification to WP01 Functions
FFT Processing Examples

Remote Control of FFT Processing

Remote Commands
Additional Values in the Descriptors of
FFT Processed Waveforms

Some practical suggestions

Relationships of 9400A FFT output waveforms to

the FFT computation steps

Computation Speed of FFT

FFT 9400A Glossary
Errors and Warnings
Table of Nyquist Frequencies
References

Index of Topics

II-I

11-3

11-4
11-7

11-7

11-9

ii-ii

II-ii

11-12
11-15

11-16
11-21
11-22
11-29
11-30

Appendix

STORE

©

LeCroy

I

44 43 42 ~ 40 39

100Ms/s

9400A DUAL 175MHz OSCILLOSCOPE sG,/s SELECT

©

"~ I .EOEF, NE

45

©

VERT GAIN PosmoN

...~+

REFERENCE DIFFERENCE

TRACKING

38

0
0

0
0

0

0
0
0
0

2

3

4

5

6
7

8

9

10

46

47

48

49

TIME MAGNIFIER

+

POSITION
(

INTERLEAVED

SAMPLING

ON

37

36

O

CHANNEL 1
OFFSET

(p:

VOLTSIDIV
5V 5mY 5V 5mV

CHANNEL 2
OFFSET

©I

VOLTSIDIV

LEVEL / DELAY

-~ -.,~+ + <..- .->-

"°

I

ilEAny

TIIIS’n

COUPLING MODE

35

34

33
32

31

,, 1"0 ,.,-1"0

LF REJ
HF RF.J

0’ ~0 ""’ ~0

I’

6ND
OC DC

I

6110 HD

\

.,,o, ~0

I

I... I,.,.

0

250 V pk MAX 250 Y pk MAX

GND

,oo,, ~0

SOURCE SLOPE

CIAll T 0 HIS

c.,~

UNE

~,1,0

EJ[TIIO

EXTERNAL

250 V pk MAX

loll

IIIOUll

.~--;-- 0

i

POWER

ON

30

29

28

27

SCREEN
DUMP

©

11

INTENSITY GRID INTENSITY DUAL GRID

o o o o

© ©

12 13

14

REMOTE

ON

15

CURSOR MEASUREMENT MODE

VOLTAGE TIME MARKER

16 17 18

9400A FRONT PANEL

Figure 1.1

PROBE CALIBRATOR

19

!10

21

22

@

I

23 24 25 26

51

52

53 54 55 56 57

9400A REAR PANEL

Figure 1.2

DIGITAL OSCILLOSCOPE

175 MHz BANDWIDTH, 100 Ms/s, 5 Gs/s

MODEL 9400A PORTABLE

DUAL-CHANNEL OSCILLOSCOPE

LeCroy

9400A

High Bandwidth and
Precision

For instant hard copies the 9400A’s screen dump feature sends data
directly to the DPgO01 8-pen digital plotter.

A wide range of oscilloscope accessories including cameras and a

scope cart (pictured) are available for the 9400A.

ORDERING INFORMATION

Oscilloscope and Options

Code

9400A/G Digital Oscilloscope
9400AOP01 High-precision Option

9400AOP03 Printer Option for 9400A/G
9400AWP01 Waveform Processing Option

9400AWP02 FFT Processing Option (requires 9400AWP01)
9400AMS01 Mass Storage and Remote Control Package, in-

9400AIM01 GPIB Interface for IBM-PCC computers
9400CS01 Calibration Software

Description

cluding an IBM lap-top controller, interface, cables
and software

Oscilloscope Accessories

OM9400A Operator’s Manual
SM9400A Service Manual

US SALES OFFICES

1-800-5-LeCroy

automatically connects you to your local sales office.

WORLDWIDE
Australia: Scient. Devices Pty, Ltd, [phone]

Austria: Dewetron Elektr. Messger&te GmbH, [phone]
Benelux: LeCroy B.V. "31~4902-89285

Canada: Rayonics Sci. Inc., W. Ontario, [phone]

E. Ontario/Manitoba, [phone]
Quebec, (514) 335-015

Denmark: Lutronic Aps, (42) 459764
Finland: Labtronic OY, (90) 847144

France: LeCroy Sad (1) 69073897
Germany: LeCroy GmbH, (06221) 49162, (North) (0405)

Innovators in Instrumentation

Copyright @ March 1990. LeCroy is the registered trademark of LeCroy Corporation. All rights reserved. Information in this publication supersedes all earlier versions. Specifications subject
to change without notice,

TDS 011/004

W. Canada, [phone]

LeCroy

LeCROY CORPORATE HEADQUARTERS

700 Chestnut Ridge Road
Chestnut Ridge, NY 10977-6499
Telephone: [phone]
TWX:[phone]

Fax: [phone]

Oscilloscope Accessories (cont’d)

CAg001
CA9002

CS9400
DPg001

94XX-FC
OC9001

P9010
Pg010/2

P9011
P9100

RM9400
SGg001
Tcg001

TC9002
TC9003

Greece: Hellenic S/R Ltd., [phone]
India: Electronic Ent., [phone]

Israel: Ammo, [phone]
Italy: LeCroy Srl, Roma [phone], Milano [phone]

Japan: Toyo Corp., [phone]
Korea: Samduk Science & Ind., Ltd., (02) 468 04914

Mexico: Nucleoelectronica SA, (905) 5693 6043
New Zealand: E.C. Gough Ltd., [phone]
Norway: Avantec AS, [phone]

Portugal: M.T. Brandao, Lta¯, [phone]
Spain: Anadig Ingenieros SA, (01) 433 24

Switzerland: LeCroy SA (022) 719 21
Sweden: MSS AB, (0764) 68100
Taiwan: Topward El. Inst., Ltd., [phone]

United Kingdom: LeCroy Ltd., (0235) 33 114

Camera (using Polaroid film) and Hood
Camera Adapter (35mm) with Hood
Certified Calibration
Digital Plotter, 8-pen A4 size

Front Cover
Oscilloscope Cart
10:1 Oscilloscope Probe
10:1 Oscilloscope Probe with 2 m cable

10:1/1:1 Oscilloscope Probe
100:1 Oscilloscope Probe

Adapter Kit for Rack Mounting
High-voltage Protector

Transit Case
Protective Cover
Transit Case for 9400A and Mass Storage

LeCROY EUROPEAN HEADQUARTERS

2, rue Pr~de-la-Fontaine
P.O. Box 341

1217 Meyrin 1-Geneva, Switzerland

Telephone: [phone] Telex: 41 90

Fax: [phone]

gnal averaging improves the signal-to-noise ratio and increases sensitivity and vertical resolu-

¯ Above, a function generator signal is averaged 40 times to show the details of a perturbation

~(t

p trace).

QTHE COMPLETE TEST
O AND MEASUREMENT

SYSTEM

The LeCroy 9400A Digital Oscilloscope is a powerful general-purpose
tool for waveform recording and analysis. Combining ease of use with a

comprehensive range of measurement and processing capabilities, it en­ables extremely precise measurements.

The LeCroy 9400A provides 1 75 MHz bandwidth, 100 megasamples/sec
8-bit ADCs, + 2 % DC accuracy (+ 1% optional), 32K memory per chan-

nel, and up to 192K of waveform storage memory¯ It is fully program mable
over RS-232-C or GPIB interfaces. Plotter drivers enable color archiving
via a wide range of digital plotters.

¯ Long Memories

¯ High-resolution Display

¯ Signal Processing and FFT

¯ Mass Storage

FEATURES

SPECIFICATIONS

High bandwidth and precision - Two independent

channels, each with 175 MHz bandwidth and a high­performance 8-bit ADC, handle input signals with

better than +2% DC accuracy (_+1% optional). The
9400A features sampling rates of 100 megasamples/
sec for transient events. Long memories and a

versatile cursor system (including voltage, time and
cross-hair cursors), give time measurements with an

accuracy of_+0.02% of the time-base setting, and reso­lution of +0.002% full scale.

High-resolution display-The 9400A’s large display
screen produces bright, stable, razor-sharp pictures of
your signal under any repetition rate conditions. Very

accurate signal comparisons are possible as up to four
waveforms (live, expanded or processed) can be dis­played simultaneously on the high-resolution screen

(1024 x 1024 pixels).

Long memories-The long 32K acquisition memories

of the 9400A Digital Oscilloscope capture waveforms
with high fidelity. At similar time-base settings, the

9400A’s long memories allow sampling rates up to 25

times faster than that of instruments which have only

1K of acquisition memory (see graph below). Faster
sampling rates ensure higher single-shot bandwidth

as well as significantly reducing problems caused by
undersampling and aliasing. The 9400A’s long memo-

ries allow displayed waveforms to be expanded up to

100 times to show the finest signal details.

>-

100 L

50

~"r-

10

5

1

0.5

10n 5On 100 n 500n I LI .U 10 ~ 50tJ

Single-shot bandwidth is a function of sampling rate. Long memories enable higher sampling rates at equal time-base settings. Above, the 9400A

(solid line) is compared to oscilloscopes with 1K (dotted line) and 512 points (dashed line) of memory. At slower time-base settings, the single-shot
bandwidth of the 9400A, expressed as Nyquist frequency, is typically 25 times higher than in oscilloscopes with 1K memory and 50 times higher than

in those with only 512 points.

SINGLE- SHOT

BANDWIDTH ( NYQUIST

\\ "’,

I \

Transient recording - With a sampling rate of 100

megasamples/sec, the 9400A is an extremely powerful
transient recorder. Long 32K data point acquisition

memories, combined with a continuously adjustable

trigger (from 100% pre-trigger to 10,000 divisions

post-trigger at any time-base setting), ensure that rare
events cannot be missed. Both channels are sampled
simultaneously so that exact time correlation is main-

tained between channels.

Full programmability - All the 9400A’s front-panel
controls are fully programmable via the two RS-232-C

interface ports or the GPIB port. A single push-button
initiates a screen dump for accurate color hard copies

of the display via a wide range of digital plotters. The
GPIB comes complete with LeCroy "MASP" software
offering computer control and mass storage on any PC
compatible with the IBM® standard.

Signal processing - The waveform processing op­tions extend the applications of the 9400A to high

bandwidth signal characterization, as well as mathe­matical and spectral analysis. The routines include

averaging (summed and continuous), smoothing, inte­gration, differentiation, square, square-root, full
arithmetic, FFT spectral analysis, and Extrema moni­toring.

Mass storage and remote control - A sophisticated
mass storage and remote control package is available
to assist users involved in automated and computer­aided testing. Convenient portability for field applica­tions is also provided by a lap-top computer.

FREQUENCY )

Vs. TIME BASE SETT[NG

\

\ ""i

\

\

,\

\

\

\

\

ioo~

TIME BASE SETTING

(sec/div)

%

\

,,soo~,,.1~

\

\

1-

¯ .=

\

\

\

\

\

VERTICAL ANALOG SECTION

Bandwidth (- 3 dB):

@ 50 ~: DC - 175 MHz at 10 mV/div, up to 225 MHz

at 1V/div;

DC - 150 MHz at 5 mV/div.

@ 1 M~ AC: < 10 Hz - 100 MHz typical.
@ 1 M~ DC: DC - 100 MHz typical.

Single shot: DC - 50 MHz (Nyquist).

Input impedance: 1 M~//50 pF and 50 ~ +_ 1%.
Channels: Two; standard BNC connector inputs.

Sensitivity range: 5 mV/div to 1 V/div at 50 ~ impedance

and 5 mV/div to 5 V/div at 1 M~ impedance; detents at

1-2-5, 1 : 2.5 continuously variable.
Offset: _+ 8 divisions in 0.04 division increments.

DC accuracy: Standard < + 2%, optional _< + 1%.

Noise: _< 0.45% RMS.
Bandwidth limiter (- 3 dB): 30 MHz.

Max input voltage: 250 V (DC + peak AC) at 1 M~, 5 V

(500 mW) or _+ 10V peak AC at 50

VERTICAL DIGITAL SECTION

ADCs: One per channel, 8-bit flash.
Conversion rate: Up to 100 megasamples/sec for transient

signals, up to 5 gigasamples/sec for repetitive signals, simul­taneously on both channels.

Aperture uncertainty: + 10 psec.
Overall dynamic accuracy (typical): Sine wave applied to

the BNC input for RMS curve fit at 80% full scale. The accu-

racy measurement includes the front-end amplifier, sample
& hold and ADC.

Input frequency Nyquist
(MHz) 1.0 10.0 50.0 100.0 175.0

Signal-to-noise
ratio (dB)

Effective bits 7.0 7.0 7.0 6.2 5.0

Acquisition memories, Channels 1 and 2: Two, 32K 8-bit
word memories (64K total) which can be segmented into

15, 31,62, 125 or 250 blocks.

Reference memories, C and D: Two, 32K, 16-bit word me­mories (64K total) which can store two acquired and/or

processed waveforms.

Function memories E and F (optional): Two 32K, 16-bit

word memories (64K total) for waveform processing.
Glitch detection: Permanent glitch detection for events

clown to 0.04% of the time-base setting, 10 nsec minimum.

41.9 41.9 41.9 37.1 29.9

HORIZONTAL SECTION

Time Base

Range: 2 nsec/div to 100 sec/div.
Accuracy: Better than + 0.002 % of the time-base setting.
Interpolator resolution: 10 psec.

Acquisition Modes
Random Interleaved Sampling (RIS) for repetitive signals

from 2 nsec/div to 2 ~sec/div;
Single shot for transient signals and repetitive signals from

50 nsec/div to 200 msec/div;

Roll for slowly-changing signals from 500 msec/div to
100 sec/div;

Sequence for capturing transients in segmented memories
of 8, 15, 31,62,125 or250 blocks.

Trigger

Sources: CHAN1, CHAN2, LINE, EXT, EXT/10.
Slope: Positive, negative, window.

Coupling: AC, LF RE J, HF RE J, DC.
Modes:

Sequence: stores multiple events in segmented acquisi-

tion memories.

Auto: automatically re-arms after each sweep. If no trig­ger occurs, one is generated at 2 Hz repetition rate.

Normal: re-arms after each sweep. If no trigger occurs
after 2 sec, the display is erased.

Single (hold): holds display after a trigger occurs. Re­arms only when the "single" button is pressed again.

Pro-trigger: Adjustable in 0.2% increments, to 100%.
Post-trigger delay: Adjustable in 0.02 division increments

up to 10,000 divisions.

External trigger input: 1M~, < 30pE 250V max., + 2V in
EXT, + 20V in EXT/10.

Rate: > 200 MHz.

SELF TESTS

Auto-calibration: Performed every 20 minutes or wheneve

the gain or time-base parameters are changed; provides
accuracies of:

DC gain: + 2% (+ 1% optional) of full scale;

Offset: + 0.5% of full scale (50~ only);
Time: 20 psec RMS.

During the warming-up period, auto-calibration is carried OL
at 1 minute intervals unless the oscilloscope is in single or

sequence trigger mode.

DISPLAY

CRT: 12.5 ×17.5 cm (5 x 7 inches); magnetic deflection; vec

tor graphics system.

Resolution: 1024 x 1024 addressable points.
Grid: Internally generated; separate intensity control for gric

and waveforms. Single and dual grid mode.
Expansion: Dual zoom horizontal expansion operates simu

taneously on live, stored and processed waveforms,
expanding up to 100 times. Vertical expansion from 0.4 up tc

2 times for non-processed waveforms, up to 10 times for
processed waveforms.

Screen dump: Single or multi-pen digital plotters are menu
selected. The 9400A supports the HP 7400 series, as well a,

the Tektronix 4662, Philips PM 8151, Graphtek WX 4638/6.
and compatible models. Screen dumps are activated by a

front-panel push-button.
Cursors: Two time cursors give time resolution of _+ 0.2% c

full scale for unexpanded traces; up to +_ 0.002% for expan­ded traces. The corresponding frequency information is alsc

provided. Two voltage cursors measure voltage differences
to 0.2% of full scale for each trace.

A cross-hair marker measures absolute voltage versus
signal ground as well as the time relative to the trigger.

DIGITAL OSCILLOSCOPE

175 MHz BANDWIDTH, 100 Ms/s, 5 Gs/s

MODEL 9400A PORTABLE

DUAL-CHANNEL OSCILLOSCOPE 9400A

¯

High Bandwidth and
Precision

¯ Long Memories

LeCroy

"ignal averaging improves the signal-to-noise ratio and increases sensitivity and vertical resolu-

in. Above, a function generator signal is averaged 40 times to show the details of a perturbation

(top trace).

THE COMPLETE TEST

AND MEASUREMENT

SYSTEM

The LeCroy 9400A Digital Oscilloscope is a powerful general-purpose

tool for waveform recording and analysis. Combining ease of use with a

comprehensive range of measurement and processing capabilities, it en­ables extremely precise measurements.

The LeCroy 9400A provides 175 MHz bandwidth, 100 megasamples/Sec
8-bit ADCs, + 2 % DC accuracy (+ 1% optional), 32K memory per chan-

nel, and up to 192K of waveform storage memory. It is fully programmable
over RS-232-C or GPIB interfaces. Plotter drivers enable color archiving
via a wide range of digital plotters.

¯ High-resolution Display

¯ Signal Processing and FFT

¯ Mass Storage

FEATURES

High bandwidth and precision - Two independent

channels, each with 175 MHz bandwidth and a high­performance 8-bit ADC, handle input signals with

better than +_2% DC accuracy (.-_1% optional). The
9400A features sampling rates of 100 megasamples/
sec for transient events. Long memories and a
versatile cursor system (including voltage, time and
cross-hair cursors), give time measurements with an

accuracy of__0.02% of the time-base setting, and reso-

lution of _+0.002% full scale.

High-resolution display- The 9400A’s large display

screen produces bright, stable, razor-sharp pictures of

your signal under any repetition rate conditions. Very
accurate signal comparisons are possible as up to four

waveforms (live, expanded or processed) can be dis-

played simultaneously on the high-resolution screen
(1024 x 1024 pixels).

Long memories- The long 32K acquisition memories
of the 9400A Digital Oscilloscope capture waveforms
with high fidelity. At similar time-base settings, the
9400A’s long memories allow sampling rates up to 25
times faster than that of instruments which have only

1K of acquisition memory (see graph below). Faster

sampling rates ensure higher single-shot bandwidth
as well as significantly reducing problems caused by

undersampling and aliasing. The 9400A’s long memo­ries allow displayed waveforms to be expanded up to

100 times to show the finest signal details.

Transient recording - With a sampling rate of 100

megasamples/sec, the 9400A is an extremely powerful

transient recorder. Long 32K data point acquisition

memories, combined with a continuously adjustable

trigger (from 100% pre-trigger to 10,000 divisions

post-trigger at any time-base setting), ensure that rare
events cannot be missed. Both channels are sampled

simultaneously so that exact time correlation is main­tained between channels.

Full programmability - All the 9400A’s front-panel
controls are fully programmable via the two RS-232-C
interface ports or the GPIB port. A single push-button
initiates a screen dump for accurate color hard copies

of the display via a wide range of digital plotters. The
GPIB comes complete with LeCroy "MASP" software

offering computer control and mass storage on any PC
compatible with the IBM® standard.

Signal processing - The waveform processing op­tions extend the applications of the 9400A to high
bandwidth signal characterization, as well as mathe-

matical and spectral analysis. The routines include
averaging (summed and continuous), smoothing, inte-

gration, differentiation, square, square-root, full

arithmetic, FFT spectral analysis, and Extrema moni-

toring.

Mass storage and remote control - A sophisticated
mass storage and remote control package is available
to assist users involved in automated and computer-

aided testing. Convenient portability for field applica­tions is also provided by a lap-top computer.

SINGLE-SHOT BANDWIDTH (NYQUIST FREQUENCY)

100

50

\

Vs. TIME BASE SETTING

\

\

l0 -

5 -

0.5 --

1On 50n lO0n

Single-shot bandwidth is a function of sampling rate. Long memories enable higher sampling rates at equal time-base settings. Above, the 9400A

(solid line) is compared to oscilloscopes with 1K (dotted line) and 512 points (dashed line) of memory. At slower time-base settings, the single-shot

bandwidth of the 9400A, expressed as Nyquist frequency, is typically 25 times higher than in oscilloscopes with 1K memory and 50 times higher than
in those with only 512 points.

SOOn Ip 5p 10FI 50H

\

\

\

\

\

\

\

\

\

\

\

\

\

%. "¯

TIME BASE SETTING

(sec/div )

\

\

\

SPECIFICATIONS

VERTICAL ANALOG SECTION

Bandwidth (- 3 dB):

@ 50 ~2: DC - 175 MHz at 10 mV/div, up to 225 MHz

@ 1 M(2 AC: < 10 Hz- 100 MHz typical.
@ 1 M(~ DC: DC - 100 MHz typical.

Single shot: DC - 50 MHz (Nyquist).
Input impedance: 1 M~2//50 pF and 50 ~-2 + 1%.
Channels: Two; standard BNC connector inputs.

Sensitivity range: 5 mV/div to 1 V/div at 50 (2 impedance

and 5 mV/div to 5 V/div at 1 M~) impedance; detents at
1-2-5, 1 : 2.5 continuously variable.

Offset: + 8 divisions in 0.04 division increments.
DC accuracy: Standard _< + 2%, optional _< _+ 1%.

Noise: < 0.45% RMS.
Bandwidth limiter (- 3 dB): 30 MHz.

Max input voltage: 250 V (DC + peak AC) at 1 M~2, 5 V

(500 mW) or _+ 10V peak AC at 50 (~.

at 1V/div;

DC - 150 MHz at 5 mV/div.

VERTICAL DIGITAL SECTION

ADCs: One per channel, 8-bit flash.
Conversion rate: Up to 100 megasamples/sec for transient

signals, up to 5 gigasamples/sec for repetitive signals, simul­taneously on both channels.

Aperture uncertainty: _+ 10 psec.
Overall dynamic accuracy (typical): Sine wave applied to

the BNC input for RMS curve fit at 80% full scale. The accu­racy measurement includes the front-end amplifier, sample
& hold and ADC.

Input frequency

(MHz) 1.0
Signal-to-noise

ratio (dB)
Effective bits 7.0 7.0 7.0

Acquisition memories, Channels 1 and 2: Two, 32K 8-bit
word memories (64K total) which can be segmented into

15, 31,62, 125 or 250 blocks.
Reference memories, C and D: Two, 32K, 16-bit word me-

mories (64K total) which can store two acquired and/or
processed waveforms.

Function memories E and F (optional): Two 32K, 16-bit
word memories (64K total) for waveform processing.

Glitch detection: Permanent glitch detection for events
down to 0.04% of the time-base setting, 10 nsec minimum.

41.9 41.9

10.0 50.0 100.0 175.0

Nyquist

41.9 37.1 29.9

6.2 5.0

HORIZONTAL SECTION

Time Base

Range: 2 nsec/div to 100 sec/div.

Accuracy: Better than + 0.002 % of the time-base setting.
Interpolator resolution: 10 psec.

Acquisition Modes

Random Interleaved Sampling (RIS) for repetitive signals

from 2 nsec/div to 2 #sec/div;

Single shot for transient signals and repetitive signals from
50 nsec/div to 200 msec/div;

Roll for slowly-changing signals from 500 msec/div to
100 sec/div;

Sequence for capturing transients in segmented memories
of 8, 15, 31,62, 125 or 250 blocks.

Trigger

Sources: CHAN1, CHAN2, LINE, EXT, EXT/10.
Slope: Positive, negative, window.

Coupling: AC, LF RE J, HF REJ, DC.
Modes:

Sequence: stores multiple events in segmented acquisi-

tion memories.
Auto: automatically re-arms after each sweep. If no trig-

ger occurs, one is generated at 2 Hz repetition rate.
Normal: re-arms after each sweep. If no trigger occurs
after 2 sec, the display is erased.

Single (hold): holds display after a trigger occurs. Re­arms only when the "single" button is pressed again.

Pre-trigger: Adjustable in 0.2% increments, to 100%.
Post-trigger delay: Adjustable in 0.02 division increments

up to 10,000 divisions.
External trigger input: 1M,(2, < 30pF, 250V max., _+ 2V in

EXT, 4- 20V in EXT/10.

Rate: > 200 MHz.

SELF TESTS

Auto-calibration: Performed every 20 minutes or whenever

the gain or time-base parameters are changed; provides
accuracies of:

DC gain: + 2% (+ 1% optional) of full scale;

Offset: + 0.5% of full scale (50~ only);

Time: 20 psec RMS.

During the warming-up period, auto-calibration is carried out
at 1 minute intervals unless the oscilloscope is in single or
sequence trigger mode.

DISPLAY

CRT: 12.5 x17.5 cm (5 x 7 inches); magnetic deflection; vec­tor graphics system.

Resolution: 1024 x 1024 addressable points.

Grid: Internally generated; separate intensity control for grid

and waveforms. Single and dual grid mode.

Expansion: Dual zoom horizontal expansion operates simul-

taneously on live, stored and processed waveforms,

expanding up to 100 times. Vertical expansion from 0.4 up to
2 times for non-processed waveforms, up to 10 times for

processed waveforms.
Screen dump: Single or multi-pen digital plotters are menu

selected. The 9400A supports the HP 7400 series, as well as
the Tektronix 4662, Philips PM 8151, Graphtek WX 4638/6,
and compatible models. Screen dumps are activated by a

front-panel push-button.
Cursors: Two time cursors give time resolution of + 0.2% of

full scale for unexpanded traces; up to + 0.002% for expan­ded traces. The corresponding frequency information is also

provided. Two voltage cursors measure voltage differences
to 0.2% of full scale for each trace.

A cross-hair marker measures absolute voltage versus
signal ground as well as the time relative to the trigger.

For instant hard copies the 9400A’s screen dump feature sends data

directly to the DP9001 8-pen digital plotter.

ORDERING INFORMATION
Oscilloscope and Options

Code Description

9400A/G Digital Oscilloscope
9400AOP01 High-precision Option

9400AOP03 Printer Option for 9400A/G
9400AWP01 Waveform Processing Option

9400AWP02
9400AMS01 Mass Storage and Remote Control Package, in-

9400AIM01 GPIB Interface for IBM-PCC computers
9400CS01 Calibration Software

FFT Processing Option (requires 9400AWP01)
cluding an IBM lap-top controller, interface, cables

and software

Oscilloscope Accessories

OM9400A Operator’s Manual
SM9400A Service Manual

US SALES OFFICES

1-800-5-LeCroy

automatically connects you to your local sales office.

WORLDWIDE
Australia: Scient. Devices Pty, Ltd, [phone]

Austria: Dewetron Elektr. Messger~te GmbH, [phone]

Benelux: LeCroy B.V. "31-4902-89285

Canada: Rayonics Sci. Inc., W. Ontario, [phone]

Denmark: Lutronic Aps, (42) 459764

Finland: Labtronic OY, (90) 847144

France: LeCroy Sad (1) 69073897

Germany: LeCroy GmbH, (06221)49162, (North) (0405)42713

E. Ontario/Manitoba, [phone]
Quebec, (514) 335-015

W. Canada, [phone]

A wide range of oscilloscope accessories including cameras and a

scope cart (pictured) are available for the 9400A.

Oscilloscope Accessories (cont’d)

CA9001
CA9002

CS9400
DP9001

94XX-FC

OC9001

P9010
P9010/2
P9011
P9100

RM9400

SG9001
TC9001
TC9002
TC9003

Greece: Hellenic S/R Ltd., [phone]
India: Electronic Ent., [phone]

Israel: Ammo, [phone]
Italy: LeCroy Srl, Roma [phone], Milano [phone]
Japan: Toyo Corp., [phone]

Korea: Samduk Science & Ind., Ltd., (02) 468 04914
Mexico: Nucleoelectronica SA, (905) 5693 6043

New Zealand: E.C. Gough Ltd., [phone]

Norway: Avantec AS, [phone]
Portugal: M.T. Brandao, Lta., [phone]

Spain: Anadig Ingenieros SA, (01) 433 24
Switzerland: LeCroy SA (022) 719 21

Sweden: MSS AB, (0764) 68100

Taiwan: Topward El. Inst., Ltd., [phone]

United Kingdom: LeCroy Ltd., (0235) 33 114

Camera (using Polaroid film) and Hood
Camera Adapter (35mm) with Hood

Certified Calibration
Digital Plotter, 8-pen A4 size

Front Cover

Oscilloscope Cart

10:1 Oscilloscope Probe
10:1 Oscilloscope Probe with 2 m cable
10:1/1:1 Oscilloscope Probe
100:1 Oscilloscope Probe

Adapter Kit for Rack Mounting

High-voltage Protector

Transit Case

Protective Cover

Transit Case for 9400A and Mass Storage

LeCROY CORPORATE HEADQUARTERS

700 Chestnut Ridge Road

LeCroy

Innovators in Instrumentation

Copyright (~ March 1990. LeCroy is the registered trademark of LeCroy Corporation. All rights reserved. Information in this publication supersedes all earlier versions. Specifications subject
to change without notice.
TDS 011/004

Chestnut Ridge, NY 10977-6499
Telephone: [phone]
TWX:[phone]

Fax: [phone]

LeCROY EUROPEAN HEADQUARTERS

2, rue Pre-de-la-Fontaine

P.O. Box 341
1217 Meyrin 1-Geneva, Switzerland

Telephone: [phone] Telex: 41 90

Fax: [phone]

In single-shot applications the 9400A’s smoothing routines can be
used to remove high-frequency noise from transients.

MASS STORAGE 9400AMS01

Optional dual floppy-disk storage system mounted externally
on the oscilloscope.

Controller: PC01 programmable controller with LCD display
and full-size keyboard.

Medium: 720 kilobyte, 3 1/2 inch flexible diskettes.

Bus transfer rate: 220 kilobytes/sec over National Instru-

ments TM GPIB interface model 80400-50.
Dimensions: 6.9 x 31.2 x 40.5 cm;

2.7 x 12.3 x 15.9 inches.

Weight: 6 kg, 13 Ibs.

For further information refer to the mass storage data sheet.

CALIBRATION SOFTWARE AND SYSTEMS
9400CSO1 "CALSOFT"

Test and calibration software poviding a convenient and un-

An apparent noise signal (top trace) is averaged over 400 times
(middle) to reveal a low amplitude clock signal. FFT analysis (lower)

shows the clock frequency to be 1.02 MHz.

ambiguous check of the 9400A’s specifications. If instru­ments traceable to a standard are used, the calibration will

be traceable to the same standard.
Computer required: Any computer compatible with the

IBM-PC standard.

Tests: A comprehensive series of tests include internal,

bandwidth, linearity, noise, rise time/overshoot, sinefit, time
base and trigger.

Presentation of results: Results of the calibration check are

fully documented on hard copy, or can be archived on hard
disk or diskette.

"CALSOFT" systems: Various system configurations includ­ing 9400CS01, signal generators, power supplies, and a

computer with accessories and fixtures are quoted on re­quest.

Training: User training classes on service and maintenance
of the 9400 series oscilloscopes, as well as calsoft operation

are scheduled regularly.

CERTIFIED CALIBRATION CS9400

Certified traceable calibration to NBS or any other national
standard is obtained by specifying CS9400 when ordering
the 9400A.

A lap-top IBM-PCC is used to provide mass storage and remote
control (9400AMSO 1) for field and automated testing applications.

Time and cross-hair cursors indicate Hz and dB or volt val­ues when an FFT spectrum analysis is made.

Menus:

Standard: Waveform storage; acquisition parameters;

memory status; store/recall front-panel configurations,

RS-232-C configuration; plotter setup.
Optional: (WP01/WP02) averaging, arithmetic, functions,
extrema, smoothing, FFT and frequency domain averag­ing.

REMOTE CONTROL

All the front-panel controls, including variable gain, offset
and position controls (not cursor positioning), and all the in-

ternal functions are programmable.
RS-232-C ports: Two: for computer/terminal control and

plotter connection. Asynchronous up to 19200 baud.
GPIB port: (IEEE-488). Configured as talker/listener for

computer control and fast data transfer; 400 kilobytes/sec
maximum. ASCII or binary. The address switches are on the

rear panel.
It includes LeCroy MS02 (MASP) IBM-PC-based software

for mass storage and remote control applications. For further
details on MASP software, please refer to the MS01/02 data

sheet.

PROBES

Probe calibration: 976 Hz square wave, 1 V p-p +_ 1%.
Standard probes: Two model P9010, xl0 attenuating pas-

sive probes with 10 M~ input impedance in parallel with a

5.5 pF capacitance.
Probe power: Two power outlets on the rear panel provide

_+ 15 V and + 5 V DC for active probes.

GENERAL

Temperature: 5 to 40°C rated; to 50°C operating.
Humidity: 80%

EMI Immunity: The 9400A complies with the following stan-

dards: IEC 801, VDE 0871, FCC PART 15 and SEV.
Safety standards: The 9400A complies with the following:

IEC-348, ASE 3453 and VDE 0411.

Power required: 110 or 220 V AC, 48 to 65 Hz, 200 W.
Battery backup: NiCd batteries maintain front-panel set-

tings for 6 months minimum.
Dimensions: (HWD) 19.2 x 36.5 × 46.5 cm,

(7 1/2 x 14 3/8 x 18 3/8 inches).

Weight: 14 kg (30 Ibs) net, 20 kg (44 Ibs) shipping.

Warranty: 2 years.

OPTIONS FOR THE 9400A

9400AOP01 : _+ 1% DC high-precision option. A certificate of

traceability is provided with this option.

9400AOP03: Printer drive for HP 2225 Think Jet.

WAVEFORMPROCESSING 9400AWP01, AND
9400AWP02

Routines are called and set up via menus. Extensive signal

processing in both time and frequency domains is provided

by optional firmware packages. These include FFT spectrum
analysis, arithmetic functions, integration, differentiation,
square root, square, averaging (continuous and summation)
and smoothing, as well as Extrema monitoring.

For additional information refer to data sheets WP01 and
WP02.

120

110

100

90

80o

70=

60=

50-

,t, 0~

30=

20=

10=

0h

10

With option WPO 1 installed, the 9400A becomes a fast signal a verager
(both summation and continuous). A s many as 100, 000 points/sec are
averaged with record lengths chosen by the user up to a maximum of
32,000. The graph above displays the relationship between record
length and the number of signals/sec averaged.

5o

u

20

u

® 10

u3

uJ
F- 5-

50 t00 500 1000

RECORD LENGTH (no. of points)

\

\

\

\

\

5000 10000

/

/

/

i 2 ____

/

t

~

,5

J

.2

50

FFT execution time as a function of record length, including window cal­culations and display generation, is expressed in the graph above.

J

125 250 625

J

1250 2500 6250

RECORD LENGTH (Points)

12500 25000

50000

WAVEFORM PROCESSING PACKAGE

INCLUDING AVERAGING, INTEGRATION, DIFFERENTIATION

LeCroL

WP01 WAVEFORM PROCESSING FIRMWARE

FOR MODEL 9400A DIGITAL OSCILLOSCOPE

9400AWP01

¯

Averaging - Summation
and Continuous

¯

Arithmetic - including Addition,
Subtraction, and Multiplication

Functions -including

Integration, Differentiation,

and Square Root

Extrema Mode - Storage of
Extreme Positive and Negative

Values

erform complex measurement sequences with ease. Above, a damped sine wave (top)

s~raining different mathematical functions together, the WP01 waveform processing package

ed (middle) and then integrated (bottom) allowing RMS mesurements to be calculated.

FOR SIGNAL

¯ CHARACTERIZATION

AND ANALYSIS

The LeCroy WP01 Waveform Processing Firmware Package offers powerful
routines that extend the use of the 9400A to signal characterization, mathe­matical analysis, and post-processing of single events. Ordered as an

option, or retrofitted, WP01 allows for further extensions of the 9400A’s pro­cessing capabilities with other firmware packages.

The LeCroy 9400A provides 175 MHz bandwidth, 100 megasamples/sec
8-bit ADCs, +2% DC accuracy (+1% optional), 32K memory per channel,
and up to !92K of waveform storage memory. It is fully programmable over

RS-232-C ’or opti0rlal GPIB interfaces. Plotter drivers enable color archiving
via a wide range of digital plotters.

¯ Smoothing - Reduction of

Noise on Single Events

FEATURES

Extensive Signal Averaging - Two operation

modes:
¯ Summation averaging up to 1,000,000 waveforms

¯ Continuous averaging with weighting factors up

to 128.
Averages up to 100,000 words/see in summation
mode.

Offset Dithering - Improves the vertical resolution
for low-noise measurements by several bits in

summation averaging mode. Reduces the effect of
ADC differential non-linearities.

Artifact Rejection - Rejects waveforms that
exceed the dynamic range of the ADC to ensure

statistical validity of summed average results.
"Extrema" Mode - Keeps track of time and ampli-

tude drift by storing extreme positive and negative
values, such as glitches, over a programmable
number of sweeps.

Powerful Arithmetic - Processes addition, subtrac­tion, multiplication or division on pairs of wave-

forms stored in the 9400A’s memory locations

CH1, CH2, C, D and E. Waveform data can be nor­malized by additive or multiplicative constants.

Complex Functions - Computes integration, dif­ferentiation, square, square root and negation on

single waveforms stored in the 9400A memory loca-

tions CH1, CH2, C, D and E. Waveform data can be

multiplied by constants.

Smoothing - Allows two smoothing modes to

reduce unwanted noise on single events:
¯ Mean value smoothing down to 50 segments
¯ N-point smoothing with up to 9-point filter.

Vertical Expansion - Provides vertical scale expan-

sion by a factor of up to 10 in signal averaging

mode.

Chaining of Operations - Automatically chains two

operations.

Example: F(E) = Average (CH1-CH2).
An indefinite number of operations can be per­formed sequentially, either manually or via remote
control.

Remote Control - Controls remotely all front-panel
settings, as well as all waveform processing options
via either GPIB or RS-232-C interfaces.

Color Archiving - Copies screen in color using a
wide range of digital plotters.

FUNCTIONAL DESCRIPTION

WP01, an optional waveform processing firmware

package for the 9400A Digital Oscilloscope, is opti-

mized for processing signals in real time. The
powerful 68000-based system permits rapid represen­tation of processed results such as averages,
differentiations, multiplications, integrations and
smoothing of waveforms.

Waveform operations can be performed on live or
stored signals, or a combination of both. They are

selected through simple menus, and it is even pos­sible to chain them and compute for example the inte­gral of the multiplication of two traces, or average the
difference of CH1 and CH2.

WP01 includes an additional 512 kilobytes random
access memory for accumulation, computation and

waveform buffering. It permits the accumulation of up
to 1,000,000 waveforms of 32000 points each.

All processing occurs in waveform memories E and F

which may be displayed on the screen by pressing

FUNCTION E, F buttons. Whenever one of the FUNC-

TIONS E or F or their expansions (EXPAND A or B)
turned on, the corresponding waveform processing is

executed and the result displayed.

SIGNAL AVERAGING

WP01 offers two powerful, high-speed signal
averaging modes to improve signal-to-noise ratio and

provide more accurate measurements. Averaging

increases the dynamic range by several bits, allowing
the sensitivity to reach #Volts.

Summed averaging consists of the repeated addition,

with equal weight, of recurrences of the selected
source waveform. Whenever the required number of
waveforms is reached, the averaging process will
stop. The total number of waveforms to be accumu-

lated can be selected between 10 and 1,000,000

sweeps in a 1-2-5 sequence. Signals exceeding the
dynamic range of the 9400A’s 8-bit ADC at any point
may be automatically rejected to ensure valid summed
averaging results.

The user may also choose to ,,dither,, the program-

mable offset of the input amplifier. Dithering uses
slightly different portions of the ADC for successive
waveforms so that the differential non-linearities are
averaged. As a result, in a low-noise application, the

measurement precision and dynamic range are
improved.

Continuous averaging, sometimes called exponential

averaging, consists of the repeated weighted average

of the source waveform with the previous average.

This mode of averaging is a continuous process. The

effect of previous waveforms gradually tends to zero.

Relative weighting factors can be chosen from 1:1 to

1:127. This averaging mode is most useful for setting

up measurements or observing noisy signals that
change with time.

EXTREMA MODE

Tracking rare glitches or monitoring signals drifting in

time and amplitude is made easy with the unique

EXTREMA mode. The computation of extrema consists

of a repeated comparison of recurrences of the source

waveform with the accumulated extrema waveform.

Whenever a given data point of the new waveform
exceeds the existing data point of the accumulated

extrema waveform it replaces it. In this way the maxi­mum and/or minimum envelope of all waveforms is
accumulated up to a maximum of 1,000,000 sweeps.

ARITHMETIC

WP01 also offers basic arithmetic operations such as
addition, subtraction, division, and multiplication.
These arithmetic functions can be performed on two
source waveforms on a point by point basis. Different
vertical gains and offsets of the two sources are auto-

matically taken into account. However, both source
waveforms must have the same time-base setting. The

first waveform may be multiplied by a constant factor

and offset by a constant.

Mean value smoothing divides the acquired signal
into a chosen number of segments and then gener-

ates the smoothed waveform in which each displayed

point corresponds to the mean value of "n" points
contained in the corresponding segment. The number
of segments can be between 50 and 32000. Mean
value smoothing takes all digitized points on the
screen into account.

N-point smoothing applies a moving average of N

points symmetrically placed around each of the 50 to

32000 selected points for display.

Each selected point Yk is replaced in the smoothed
waveform by a processed point Y’k corresponding to:

MATHEMATICAL FUNCTIONS

Mathematical functions such as negation, square,
square root, integral and differentiation are performed
on a single source waveform. The waveform may be

multiplied by a constant factor and may be offset by a
constant. Arithmetical and mathematical functions may
be chained by using memory C and D.

SMOOTHING

WP01 provides two types of smoothing to decrease

signal noise of single transient acquisitions.

SPECIFICATIONS

SUMMATION AVERAGING
Number of sweeps: 10 to 1,000,000 can be selected

in a 1-2-5 sequence.
Number of points averaged over CH1, CH2:50 to
32000 in 10 steps.
Offset dithering: up to 6 LSBs may be chosen.
Artifact Rejection: ON/OFF

Theoretical signal-to-noise improvement achievable:

57 dB.
Vertical expansion: 10 times maximum.
Maximum sensitivity: 500/~V/div after vertical

expansion.

CONTINUOUS AVERAGING

Number of sweeps: infinite.

Weighting factors selectable: 1:1, 1:3, 1:7, 1:15, 1:31,

1:127.

Number of points averaged: 50 to 32000 in 10 steps.

Vertical expansion: 10 times maximum.

Maximum sensitivity: 500/JV/div after vertical

expansion.

AVERAGING SPEED

The figures below assume that the display time

between triggers is negligible:

(N-1)/2

Y’ (k) =

n= -(N-1)/2

where, in case of a 3-point filter,
N -- 3; C1 --- 1/4; Co -- 1/2; C1 = 1/4

The number of points N can be selected to be 3, 5, 7
or 9.

In interleaved sampling mode, the averaging speed is

reduced as more signals are required to complete a

displayed waveform.

WAVEFORM ARITHMETIC

Addition, subtraction, multiplication, and ratio can be
performed on two live waveforms from CH1 and CH2,
or from stored waveforms in memories C, D and E.

Example:

Number of points processed: from 50 to 32000 can
be selected in 10 steps.
Multiplicative constants: from 0.01 to 9.99 can

be selected in steps of 0.01.

Additive constant: from - 9.99 to 9.99 divisions can

be selected in steps of 0.01.

Vertical expansion: 2 times maximum.

Typical execution time for 1250 points: 600 msec.

WAVEFORM FUNCTIONS

Integration, differentiation, square, square root,
negation (invert).

E = CH1 - CH2
F = CH2 * D

F=CH1 +E

C(n) Y(k+n)

record length summation

(= of points) (sweeps/sec)

32000 3
25000 4

12500 6

6250
2500 32

1250

625 73
250 100

125 112

50

13
51

118

Examples: E=./’ CH1 dt

F = - CH2

dD

E=

dt

Number of points processed: from 50 to 32000 can
be selected in 10 steps.
Multiplicative constants: from 0.01 to 9.99 can be
selected in steps of 0.01.

Additive constant: from -9.99 divisions to 9.99

divisions can be selected in steps of 0.01.

Vertical expansion: 2 times maximum.
Typical execution time for 1250 points:

400-1000 msec.

MEAN VALUE SMOOTHING
Number of adjacent blocks processed: 50 to 32000 in

10 steps,
Number of points per block: varies with the time base

and the number of blocks selected,

Typical execution time for 1250 points: 700 msec.

N-POINT SMOOTHING

Filter coefficients with weighting factors for successive

data points:

3 point - (1:2:1) 1/4
5 point - (1:4:6:4:1) 1/16

7 point - (1:6:15:20:15:6:1) 1/64

9 point- (1:8:28:56:70:56:28:8:1) 1/256.

Number of points processed: 50 to 32000 in 10 steps.
Vertical expansion: 2 times maximum.

Typical execution time of 1250 points: 500 msec.

Number of sweeps: selected in a 1-2-5 sequence

from 1 up to 1,000,000.
Number of points processed: 50 to 32000 in 10 steps.

Glitches as short as 10 nsec or 0.04% of the time­base setting are displayed.

Vertical expansion: 2 times maximum.
Typical execution time for 1250 points: 300 msec.

CHAINING OF OPERATIONS

Two functions can be automatically chained using
functions E and F.

Example:

E = CH1 - CH2
F = summed average of E

Manual chaining using memory C and D for
intermediate results may continue indefinitely.

REMOTE CONTROL

All front-panel controls and Waveform Processing
functions are fully programmable via either the

9400A’s GPIB or RS-232-C interfaces. Simple English-

like mnemonics are used.

EXTREMA MODE

Logs all extreme values of a waveform over a pro­grammable number of sweeps. Maxima and minima
are displayed separately by ROOF and FLOOR traces.

The +_ 1 V amplitude sine wave in channel 1 (upper trace) is squared
(function E: 1 * 1, lower trace) and then integrated (functions F:IE).

The value of the integral between the two cursors is 4.00 pV2s. the
RMS value can be calculated with the formula RMS =

( 1_. ,/" V2dt)

At

I/2

In this case: RMS = (1. 414V2s)

8ps

1/2

= 0.707 V.

STORED FRONT PANELS

Up to 7 front-panel setups, including WP01 menus,
can be stored and recalled by the menu buttons at
the left side of the 9400A screen.

A fast negative going signal at 5 nsec/div (upper trace) recorded
Random Interleaved Sampling mode is inverted and stored in
memory C (lower trace). Integral and differential are shown
function E and function F. The area under the inverted curve is

measured by first defining the area with the time cursors and then
reading the value of C, In this case: 11.44 nVs.

LeCROY CORPORATE HEADQUARTERS

700 Chestnut Ridge Road

LeCroy

Innovators in Instrumentation

Copyright © January 1989 LeCroy is the registered trademark of LeCroy Corporation All rights reserved¯ Information in this publication supersedes all earlier versions. Specifications subject to change
without notice
TDS 013/QO2

Chestnut Ridge, NY 10977-6499
Telephone:[phone]

TWX: [phone]
Fax: [phone]

Other sales and service representatives throughout the world.

800-5-LeCroy (532 769)

LeCROY EUROPEAN HEADQUARTERS

Route du Nant-d’Avri1101
P.O. Box 341

1217 Meyrin 1-Geneva, Switzerland
Telephone:[phone] Telex: 419058
Fax: [phone]

FAST FOURIER PROCESSING PACKAGE

25,000 POINT TRANSFORMS, SPECTRAL AVERAGING

WP02 SPECTRUM ANALYSIS FIRMWARE
FOR MODEL 9400A DIGITAL OSCILLOSCOPE

¯ 50 to 25,000 point FFTs over

¯ Frequency Resolution from

¯ Up to 5 GS/sec Sampling Rate

LeCroy

9400AWP02

Two Channels Simultaneously

1 Milli-Hz to 50 MHz

~nodulated signal (top trace) is analyzed in the frequency domain using the 9400A’s FFT
~cessing capability which provides power (middle) and magnitude (lower) information.

5ide lobes 6 kHz from the fundamental frequency are clearly visible.

FREQUENCY DOMAIN

MEASUREMENTS

AND ANALYSIS

The WP02 Spectrum Analysis Firmware Package brings powerful FFT
routines to extend the capabilities of the 9400A Digital Oscilloscope into
frequency domain measurement and analysis. It is available as an option,

or may be retrofitted.
The LeCroy 9400A provides 175 MHz bandwidth, 100 megasamples/sec

8-bit ADCs, +2% DC accuracy (+__1% optional), 32K memory per channel,
and up to 192K of waveform storage memory. It is fully programmable over

RS-232-C or optional GPIB interfaces. Plotter drivers enable color archiving
via a wide range of digital plotters.

¯ Time and Frequency Domain

Averaging
Wide selection of FFT Display

Formats and Window

Functions

FEATURES

Long Record Transforms - Extremely long record

FFTs (up to 25,000 points) provide significant
signal-to-noise ratio improvement on single
phenomena.

Wide Band Frequency Domain Analysis - Covers
wide DC to 175 MHz bandwidth with high

resolution in the frequency domain.
High Sampling Rates - Up to 5 gigasamples/sec

effectively eliminates atiasing errors.
Broad Spectrum Coverage - Executes FFTs over

record lengths as long as 25,000 data points
giving up to 12,500 spectral components at almost
any sampling rate.

Dual Input Channels - Both input channels can be
analyzed simultaneously to allow comparison of

independent signals for common frequency­domain characteristics.

Fast Processing - FFTs are processed and
displayed rapidly, e.g. a 1,250 point waveform is

transformed in less than 1.75 sec, a 50 point

waveform within 300 msec.

Versatile Display Formats - Frequency-domain

data may be presented as magnitude, phase, real,
imaginary, log-power, Iog-PSD (power spectral
density); and all may be selected via menu options
after signal capture.

Standard Window Functions - Rectangular for

transient signals; von Hann (Harming) and

Hamming for continuous waveform data; Flattop for
accurate amplitude measurements; Blackman­Harris for maximum frequency resolution.

User-definable Window Functions - Specially
defined window functions can be loaded over GPIB
and stored in the 9400A’s reference memories.

Frequency Domain Averaging - Averages up to
200 FFT results to reduce base-line noise and

allows analysis of phase-incoherent and non­triggerable noisy signals.

Time Domain Averaging - Can increase the

dynamic range up to 72 dB or more when
averaging real-time signals prior to FFT execution.
Offset dithering helps to improve dynamic range

and reduces ADC non-linearity effects.

Frequency Cursors - Cursors give up to 0.008%

frequency resolution and measure power or

voltage differences to 0.2% of full scale.

Automatic DC Suppression - DC signal

components may be suppressed automatically
prior to FFT execution (menu selected).

Full Documentation - The 9400A Digital
Oscilloscope status in the Frequency Domain is

fully documented on one comprehensive display

page specifying Nyquist frequency, number of
points, vertical scaling, window function, etc.

Chaining of Operations - Chains two operations
automatically, e.g. Function F = FFT of

(CH1 X CH2). Any number of operations may
performed sequentially, either manually or via

remote control.
Full Remote Control - All front-panel settings and

waveform processing functions are programmable
via GPIB and/or RS-232-C interfaces. Acquired
and processed waveforms can be downloaded to a

computer and can later be retrieved and displayed
on the 9400A.

Color Archiving - Provides color hard copies of
the screen, using a wide range of digital plotters.

Calibrated Vertical Scaling - Flattop truncation

window provides precisely calibrated vertical

scaling for all spectral components.

FFT BRINGS STRONG SPECTRAL ANALYSIS CAPABILITIES
TO THE 9400A

POWERFUL PERFORMANCE IN A WIDE RANGE
OF APPLICATIONS

The versatility and performance of the WP02-FFT
package with the 9400A make it an ideal tool for a

variety of applications such as:
Electronic engineering - As a very high performance

spectrum analyzer it is extremely useful for measuring
phase noise, characterizing filters, amplifier bandwidth

roll-off, or harmonic distortion.

Communications - The FFT analyzer is ideal for
characterizing HF links, modems and data links, cable
TV, PCM, fiber optics, etc.

Acoustic devices - Covers the entire audio spectrum
in one FFT operation from 25 kHz downwards with

2 Hz resolution.

Preventive maintenance systems - With a motion
transducer (accelerometers/velocity and/or
displacement transducers), the 9400AWP02 package
can be used to analyze the vibration signatures of
rotating and reciprocating machinery for early
detection of wear or damage.

Non-destructive test engineering - The high
bandwidth and sampling rate of the 9400A, together
with its long memories, make it a valuable instrument
for ultrasound non-destructive testing. "Long record
FFTs" provide unprecedented spectral resolution,
hence improved characterization of the material under
test, and much shorter measuring times.

X- (FFT (2))

.2MHz 10mY

T/dry 20 ~s Ch 2>~] mV
Trlg- 1.56 dLv + CHAN 2 =

A 2 MHz signal is frequency modulated with a 99 kHz sine wave. To
improve the signal-to-noise ratio on the phase-incoherent FM signal,
spectral averaging of 64 spectra is used (bottom trace). The part

the spectrum at the right-hand side is the 2nd harmonic of the carrier
with sidebands.

The FFT menu documents all the relevant parameters.

LeCROY CORPORATE HEADQUARTERS
700 Chestnut Ridge Road

LeCroy

Innovators in Instrumentation

Copyright @ March 1990. LeCroy is the registered trademark of LeCroy Corporation. All rights reserved, information in this publication supersedes all earlier versions. Specifications subject
to change without notice.

TOS 013/003

Chestnut Ridge, NY 10977-6499

Telephone: [phone]
TWX:[phone]

Fax: [phone]
Other sales and service representatives throughout the world.

Long records allow higher sampling rates, to reduce aliasing. A
110 kHz square wave is recorded over 1250 and 6250 points with

sampling rates of 200 and 40 nsec/point respectively. The bottom
trace, a short record transform, has considerable aliasing whereas
the longer record transform (top) is alias-free.

LeCROY EUROPEAN HEADQUARTERS

2, rue Pr@-de-la-Fontaine

P.O. Box 341
1217 Meyrin 1-Geneva, Switzerland

Telephone: [phone] Telex: 41 90
Fax: [phone]

Ch 1 20 mV

~

FUNCTIONAL DESCRIPTION

FOURIER PROCESSING

Fourier processing is a mathematical technique
which permits a time-domain waveform to be
described in terms of frequency-domain magnitude
and phase, or real and imaginary spectra. In spec­tral analysis, a waveform can be sampled and digi­tized, then transformed by a discrete Fourier trans-

form (DFT). Fast Fourier Transforms are a set of
algorithms used to reduce the computation time

(by better than a factor of 100 for a 1000 point
FFT) needed to evaluate a DFT. The principal

advantage of the FFT is the rapidity with which it
can analyze large quantities of waveform samples.
In effect, using standard measurement techniques,
it converts a time-domain instrument into digital

spectrum analyzer.

The WP02 Fast Fourier Processing Package enhances
the outstanding features of the LeCroy 9400A Digital
Oscilloscope. It provides high resolution, wide-band
spectrum analysis capabilities along with sophisticat­ed window functions and fast processing.

FFT AND THE LeCROY 9400A DIGITAL
OSCILLOSCOPE

In FFT mode, the 9400A provides measurement capa­bilities superior to those of common swept spectrum
analyzers.

In particular, it is now possible to perform spectral
analysis on continuous and single events at an eco-

nomic price. And it enables users to obtain time and
frequency values simultaneously and to compare
phases of the various frequency components with
each other. Rather than the commonly used "power of
two" record lengths the routines used in the WP02
package feature decimal record lengths, which can be
selected in a 1-2-5 order. Resulting spectra are there­fore also calibrated in convenient decimal Hertz
values.

The FFT’s digital nature ensures high accuracy, stabil­ity and repeatability. These are strongly supported by
the 9400A’s superb DC and dynamic accuracy speci­fications, such as standard +2%, optional 4-1%, DC
accuracy, high effective-bit count and increased reso­lution through signal averaging and dithering.

With the 9400A, signals may be acquired and proces­sed simultaneously using Channels 1 and 2. This is
particularly useful when looking for common fre­quency-domain characteristics in both signals or for
characterization of networks.

IMPROVED RESOLUTION

The Fast Fourier Transform calculates equally-spaced
frequency components from DC to the full 9400A

bandwidth. By lowering the sampling rate, it is pos­sible to make measurements with 1 milli-Hertz resolu-

tion up to 12,5 Hz (Nyquist). By increasing the sam­pling rate to 5 gigasamples/sec (200 psec/point)

Random Interleaved Sampling mode, the widest reso­lution becomes 50 MHz and the Nyquist frequency

2.5 GHz... comfortably above the highest frequency
components recordable by the 9400A, thus virtually

eliminating aliasing effects.

VERSATILE WINDOW FUNCTIONS

The WP02-FFT software provides a selection of win­dow functions, designed to minimize leakage and to
maximize spectral resolution of single and non-cyclic
events. These include the familiar rectangular or

unmodified window typically used for transient events,
the von Harm (Planning) and Hamming windows for

continuous signals, and, in addition, Flattop and

Blackman-Harris windows for more precise amplitude
(power) measurements or strong suppression of side
lobes respectively.

Furthermore, user-defined window functions may be
loaded onto the 9400A via the GPIB interface. Through
multiplication, they modify the acquired signal follow-

ed by FFT in an automated fashion.

SPECIFICATIONS

VERTICAL ANALOG SECTION

Inputs: two; BNC connectors.
Sensitivity: 5 mV/div to 1 V/div at 50 £~ impedance

and 5 mV/div to 5 V/div at 1 M£) impedance; detents
at 1-2-5, variable 1:2.5.

DC accuracy: standard <_ _+ 2%; optional _< _+ 1°.
Bandwidth (-3 dB):

@ 50 (5: DC - 175 MHz at 10 mV/div, up to

225 MHz at 1 V/div;
DC - 150 MHz at 5 mV/div.

@1 M~2 AC: 10 Hz-100 MHz typical

@1 M~ DC: DC-100 MHz typical

Bandwidth limiter: 30 MHz (-3 dB).
Input impedance: 1 M£~//50 pF and 50 £2

characteristic.
Maximum input: 250 V (DC + peak AC) at 1 M~
5 V DC (500 mW) or 4- 10 V peak AC at 50 ~2.

Offset: _+ 8 divisions in 0.04-division increments.

MEMORIES
Acquisition memory: 32K x 8 bits per channel

(CH1 and CH2).
Reference memory: 32K x 16 bits per reference

memory (C and D).
Function memory: 32K x 16 bits per function memory

(E and F).
The content of the acquisition and function memories
can be stored in reference memories C and D.

Record length selection for FFT

Function memories E and F only: 50-25000 data
points in 9 steps in 1-2-5 sequence. Record lengths
are selected by decimation after signal acquisition.
This implies that the Nyquist criterion can be adjusted

and optimized after signal acquisition and prior to FFT
execution.

Blackman-Harris

Flattop

REMOTE CONTROL

All front-panel controls and WP01 and WP02
processing functions are fully programmable via the
9400A GPIB and RS-232-C interfaces. Simple
English-like mnemonics are used.

STORED FRONT PANELS

Up to 7 front-panel setups, including WP01 and WP02
menu settings can be stored and recalled by the
menu buttons at the left side of the 9400A screen.

WP02-FFT INSTALLATION

A WP02-FFT package may be retrofitted to a LeCroy

9400A Digital Oscilloscope. The WP01 Signal
Processing hardware and software is a prerequisite

for installation of WP02.

Hamming

von Hann (Hanning)

The sum of two 1 V p-p sinusoids of 500 kHz and 527.5 kHz is
digitized over 2,500 points and transformed to the frequency domain.
4 different window functions are applied to indicate their effect on

leakage suppression and spectral resolution. The vertical scale factor
is 10 dB/div, 80 dBm full scale.

Long records give wide frequency span. FFT of 1000 Hz sine­amplitude modulated square wave, recorded over 25,000 points,

shows harmonics up to 25 kHz. Expansion shows sidebands at 10 Hz
and -30.1 dB.

ORDERING INFORMATION
Oscilloscope and Options

Code

9400A

9400AOP01 High-precision option (+_ 1% DC accuracy)
9400AWP01

9400AWP02Fast Fourier processing option (requires
9400AMS01 Mass storage and remote control package,

9400AIM01 GPIB interface for IBM-PCC computers

Oscilloscope Accessories

OM9400A
SM9400A Service Manual

CA9001
CA9002 Camera adapter (35 mm) with Hood
CS9400 Certified Calibration

DP9001 Digital Plotter, 8-pen A4 size

OC9001 Oscilloscope Cart

RM9400

SG9001 High-voltage protector
TC9001 Transit Case

TC9002 Protective Cover

Description

Digital Oscilloscope
Waveform processing option

9400AWP01 )
including an IBM lap-top controller, interface,

cables and software

Operator’s Manual
Camera (using Polaroid film) and Hood

Adapter Kit for Rack Mounting

FREQUENCY

Frequency range: DC to > 175 MHz.
Frequency resolution: 1 mHz to 50 MHz.

Nyquist frequency range: 25 mHz to 2.5 GHz.
Frequency scale factors; 5 mHz/div to 500 MHz/div in

1-2-5 sequence.

Frequency accuracy: 0.008% at center lobe.
Horizontal expansion: up to 100 times.

Cursors: Differential (arrows) and absolute (crosshair)

provide frequency and related amplitude measurements.

AMPLITUDE AND PHASE
General

Amplitude accuracy: see window functions table below.
Signal overflow: A warning indication is provided at

the top of the 9400A display when the input signal

exceeds the ADC range.
DC suppression: selected via the menu (ON/OFF),

removes DC component prior to FFT execution.
Cursors: Horizontal bars provide differential amplitude
measurements.

Number of traces: Time domain and frequency
domain data can be displayed simultaneously (up to

4 traces).

Spectrum Display Formats and Scaling

Real spectrum, in V/div, zero base line at 0 div (center

of screen).

Imaginary spectrum in V/div, zero base line at 0 div.
Power spectrum in dBm.

Power spectral density in dBm.
Frequency Domain Averaging up to 200 spectra for

power, PSD or magnitude.
Log display applies to power and PSD spectra in

10, 5, 2 or 1 dB/div; 80 clB display range.
Markers at left edge of screen give absolute dBm

reference (0 dBm is 1 mW into 50 ~).

Phase

Phase range: + 180 degrees to - 180 degrees.
Phase accuracy: ___ 5 degrees.

Phase scale factor: 50 degrees/div.

Zero base line: 0 div (center of screen).

Calibrated Vertical Expansion

All spectra formats, up to 10 times, in 1-2-5 sequence.

Window Functions

Selected in menu: Rectangular, von Hann (Hanning),
Hamming, Flattop, Blackman-Harris and user
definable. The table below gives filter pass band

shape and resolution:

FILTER PASS BAND AND RESOLUTION

Window
type

Rec-

tangular
von Hann

Hamming
Flattop
Blackman.

Harris

Filter band.

width at Highest

6dB side lobe Loss width

(freq. bins) (dB)

1.21

2.00 --32

1.81

1.78 --44 0.01

1.81 --67

--13 3.92 1.0

--43 1.78 1.36

Scallop Noise band-

(dB at bin) (freq. bins)

1.42 1.5

2.96

1.13 1.71

Definitions

Filter bandwidth at -6dB characterizes the frequency
resolution of the filter.
Highest side lobe indicates the reduction in leakage
of signal components into neighboring frequency bins.
Scallop loss gives amplitude accuracy of the

magnitude spectrum.
Noise bandwidth is the bandwidth of an equivalent
rectangular filter.

FFT EXECUTION TIME
FFT execution times, including window calculations

and display generation, are provided in the graph

below:

z.c

,_0

v
LU

5-

/

/

X
L~

u_

/

jJ

50

WP01 SIGNAL AVERAGING/ARITHMETIC
PROCESSING (Prerequisite for WP02)

Summation averaging: 10-1,000,000 signals.

Continuous averaging: infinite number of signals,

weighting factors 1, 3, 7, 15, 63, 31,127.

Waveform arithmetic: +, -, *, +.
Waveform functions: integration, differentiation,

square, square root, negation (inversion).

Smoothing: 1-, 3-, 5-, 7-, 9-point filters.

Extrema: records extreme values (envelopes) over

programmable number of sweeps.

CHAINING OF OPERATIONS

Two functions can be automatically chained using
functions E and F.

Examples: fnE = CH1 * CH2

Manual chaining using memories C and D for
intermediate results may continue indefinitely.

125 250 625

fnF = FFT of fnE
fnE = FFT of CH1
fnF = Integral fnE

/

/

1250 2500 6250

RECORD LENGTH (Points)

12500 25000

/

m

SECTION I

GENERAL INFORMATION

I.I

Warranty

LeCroy warrants its oscilloscope products to operate within
specifications under normal use, and services them for a period of two

years from the date of shipment. Spares, replacement parts and repairs
are warranted for 90 days. Software is thoroughly tested but is

supplied "as is" with no warranty of any kind covering detailed
performance. Accessory products not manufactured by LeCroy are covered

solely by the warranty of the original equipment manufacturer.

In exercising this warranty, LeCroy will repair or, at its option,

replace any product returned to the Customer Service Department or an

authorized service facility within the warranty period, provided that

the warrantor’s examination discloses that the product is defective due
to workmanship or materials, and that the defect has not been caused by

misuse, neglect, accident or abnormal conditions or operation.

The purchaser is responsible for the transportation and insurance
charges arising from the return of products to the servicing facility.

LeCroy will return all in-warranty products with transportation
prepaid.

This warranty is in lieu of all other warranties, expressed or implied,

including but not limited to any implied warranty of merchantability,
fitness, or adequacy for any particular purpose or use. LeCroy shall
not be liable for any special, incidental, or consequential damages,

whether in contract, or otherwise.

1.2

Assistance and Maintenance Agreements

Answers to questions concerning installation, calibration, and use of
LeCroy equipment are available from the Customer Service Department,
700 Chestnut Ridge Road, Chestnut Ridge, New York 10977-6499, U.S.A.,

[phone], and I01 Route du Nant drAvril, 1217 Meyrin i, Geneva,
Switzerland, (41)22/782-33-55, or your local field engineering office.

LeCroy offers a selection of customer support services. For example,

maintenance agreements provide extended warranty and allow the customer

to budget maintenance costs after the initial two year warranty has

expired. Other services requested by the customer such as installation,

training, on-site repair, and addition of engineering improvements are

made available through specific Supplemental Support Agreements.

General Information

I-i

1.3 Documentation Discrepancies

LeCroy is committed to providing state-of-the-art instrumentation and
is continually refining and improving the performance of its products.

While physical modifications can be implemented quite rapidly, the

corrected documentation frequently requires more time to produce.

Consequently, this manual may not agree in every detail with the
accompanying product. There may be small discrepancies in the values of

components for the purposes of pulse shape, timing, offset, etc., and,

occasionally, minor logic changes. Where any such inconsistencies

exist, please be assured that the unit is correct and incorporates the

most up-to-date circuitry.

1.4 Service Procedure

Products requiring maintenance should be returned to the Customer
Service Department or authorized service facility. If under warranty,
LeCroy will repair or replace the product at no charge. The purchaser
is only responsible for the transportation charges arising from return

of the goods to the service facility.

For all LeCroy products in need of repair after the warranty period,
the customer must provide a Purchase Order Number before any equipment

which does not operate correctly can be repaired or replaced. The

customer will be billed for the parts and labor for the repair as well

as for shipping.

1.5 Return Procedure

To determine your nearest authorized service facility, contact the

factory or your field office. All products returned for repair should
be identified by the model and serial numbers and include a description
of the defect or failure, name and phone number of the user, and, in

the case of products returned to the factory, a Return Authorization
Number (RAN). The RAN may be obtained by contacting the Customer

Services Department in New York on 914-578-6059, in Geneva on

(022) 782-33-55 or your nearest sales office.

Return shipments should be made prepaid. LeCroy will not accept C.O.D.
or Collect Return Shipments. Air-freight is generally recommended.
Wherever possible, the original shipping carton should be used. If a

substitute carton is used it should be rigid, and should be packed such

that the
excelsior
shipment,
displayed

to the proper department within LeCroy.

product is surrounded with a minimum of four inches of

or a similar shock-absorbing material. In addressing the

it is important that the Return Authorization Number be

on the outside of the container to ensure its prompt routing

General Information

1-2

1.6

Initial Inspection

It is recommended that the shipment be thoroughly inspected immediately
upon delivery to the purchaser. All material in the container should be

checked against the enclosed Packing List. LeCroy cannot accept
responsibility for shortages in comparison with the Packing List unless

notified promptly. If the shipment is damaged in any way, please

contact the factory or local field office immediately.

1-3

General Information

2.1 Introduction

The LeCroy 9400A is a high-performance digital oscilloscope suited to

research and to test and measurement applications. It is used to

capture, analyze, display and archive electrical waveforms in fields
such as electronic engineering, physics research, automated testing and

measurement, telecommunications, electromagnetic pulse and interference
measurement, LIDAR technology and ultrasonics research.

2.2 9400A Architecture

The 9400A has been built around the powerful 68000 microprocessor which
is used by the unit to perform computations and control oscilloscope
operation.

SECTION 2

PRODUCT DESCRIPTION

Att~uator Amplifier 5omple 4. AOC

AC

Offsel Gain ....

hold memory

9400A BLOCK DIAGRAM

Acqulsition Processor +

interfaces

r15112C

!

""

Figure 2.1

2-1

Product Description

All front panel rotary knobs and push buttons are constantly monitored

by the internal processor, and front panel setups are rapidly
reconfigured via the unit’s internal 16-bit bus. Data are quickly

processed according to the selected front panel setups, and are

transferred to the acquisition memory for direct waveform display or

stored in the 9400A’s reference memories.
The 68000 controls the unit’s two RS-232-C ports which are used to

directly interface the 9400A to a digital plotter, remote terminal or
other slow-speed device and also controls GPIB (IEEE-488) operation
when the 9400A is equipped with the I/O option, OP02.

2.3

ADCs and Memories

The 9400A’s two identical input channels are equipped with a
I00 megasample/second (megasample/sec), 8-bit ADC and a 32 kiloword
acquisition memory (See Figure 2.1). This dual ADC architecture ensures
absolute amplitude and phase correlation, maximum ADC performance for
both single and dual channel acquisition modes, large record lengths
and high time resolution.

The 9400A’s two 32K acquisition memories simplify transient capture by
providing very long waveform records that capture waveform features
even when trigger timing is uncertain. In addition, very accurate time

measurement is made possible by a digitally controlled zoom providing
an expansion factor of up to I00 times the time base speed.

The 9400A oscilloscope is capable of acquiring and storing repetitive
signals at a Random Interleaved Sampling rate of 5 gigasamples/second

(gigasamples/sec). An exclusive high-precision time digitizing
technique enables measurement of repetitive signals to a bandwidth of

175 MHz at an effective measuring interval of 200 psec.

The 9400A’s very low aperture uncertainty of 10 psec assures precision
measurements over its entire range as indicated by the table below:

Overall* dynamic accuracy (typical), RMS sine wave curve fit

Input Frequency (MHz)

Signal-to-noise Ratio (dB) 41.9

Effective bits

* including the front-end amplifier, sample and hold and ADC

1 10 50 100 175

41.9 41.9 37.1 29.9

7.0

9400A PERFORMANCE

Table 2.1

2-2

7.0

7.0 6.2 5.0

Product Description

2.4 Trigger

The 9400A’s digitally-controlled trigger system offers facilities such
as pre-trigger recording, bi-slope and window triggering, sequence and

roll modes in addition to the standard operating modes of Auto, Normal
and Single (Hold). The trigger source can be external or can be either
of the two inputs, and the coupling is selected from AC, LF REJect,
HF REJect and DC.

2.5 Automatic Calibration

The 9400A has an automatic calibration facility that ensures overall
vertical accuracies of ± 2% (optionally ± 1%) and ± 20 psec RMS for the

unit’s crystal-controlled time base.

The time base is calibrated each time the 9400A’s time base control is
adjusted to a new TIME/DIV setting; vertical gain and offset

calibration take place each time the front panel fixed gain control for
either CHAN i or CHAN 2 is adjusted to a new VOLTS/DIV setting.
Calibration of both channels also takes place each time the BANDWIDTH
LIMIT push button is pressed.

Further information on automatic
Section 9.4, "Auto-calibration".

2.6 Display

The 9400A’s large 12.5 cm x 17.5 cm (5 x 7 inches) screen displays

analog waveforms with high precision and serves as an interactive,
user-friendly interface via a set of screen-oriented push buttons

located immediately to the left and right of the CRT.

The oscilloscope displays up to four waveforms, while simultaneously

reporting the parameters controlling signal acquisition. In addition,
the screen presents internal status and measurement results, as well as

operational, measurement, and waveform analysis menus.

A hard copy of the 9400A’s screen is available via the unit’s dedicated

plotter port.

2.7 Manual and Programmed Control

The 9400A’s front panel layout and operation will be very familiar to
users of analog oscilloscopes. The interactive software menus assist in

quickly utilizing the recording and processing capability of the 9400A

to its full potential.

calibration may be found in

2-3

Product Description

The 9400A has also been designed for remote control operation in
automated testing and computer aided measurement applications. The
entire measurement process, including dynamic modification of front

panel settings and display organization, can be controlled via the rear

panel RS-232-C and optional GPIB (IEEE-488) ports. GPIB control
enables direct interfacing between the 9400A and a host computer at
data transfer rates of up to 400 kilobytes/sec.

The LeCroy 9400A is capable of storing up to seven front panel setups
which may be recalled either manually or by remote control, thus

ensuring rapid oscilloscope front panel configuration. When the power

is switched on, the 9400A’s front panel settings are the same as when

it was last used.

2-4

Product Description

SECTION 3

INSTALLATION

3.1

3.2 Operating Voltage

Safety Information

The 9400A has been designed to operate from a single-phase power source
with one of the current-carrying conductors (neutral conductor)
ground (earth) potential. Operation from power sources in which both
current-carrying conductors are live with respect to ground (such as
phase-to-phase on a tri-phase system) is not recommended, as the 9400A

is equipped with over-current protection for one mains conductor only.

The 9400A is provided with a three-wire electrical cord containing a

three-terminal polarized plug for mains voltage and safety ground
connection. The plug’s ground terminal is connected directly to the

frame of the unit. For adequate protection against electrical hazard,
this plug must be inserted into a mating outlet containing a safety

ground contact.

Prior to powering up the unit, make certain that the mains voltage for
your area corresponds to the mains voltage value appearing in the
window of the selector box at the rear of the 9400A.

The operating voltage for the 9400A is either 115 V or 220 V at 48 to
62 Hz. Switching from one mains voltage to another is not possible. If

the mains voltage appearing in the window differs from that used in

your area contact the nearest LeCroy sales office or distributor.

*CAUTION*

If a 9400A set for 115 V is plugged into a 220 V power source, severe
damage can occur. Before powering up the unit, ensure that the corect

line voltage has been set.

Installation

3-i

3.3

Switching on the 9400A

Switch on the 9400A by setting the POWER switch (26) to the
position.An auto-calibration takes place and the grid is displayed

after approximately 15 seconds.

Note that the 9400A is reset to the configuration it was in prior being

to switched off.

3-1

Installation

SECTION 4

DISPLAY LAYOUT

The 9400A’s CRT area is divided between the centrally located grid and
six other fields. Traces from the acquisition or reference memories are
displayed on the grid. A dual grid system is also available by pressing
push button 14 (see Figure 1.1). The six fields are used to display
such information as interactive menu queries and responses, current
acquisition parameters, relative and absolute time and voltage
measurements, and messages to assist the user.

°.

..

4.1 Menu Field (I)

This field is divided into nine sub-fields associated with menu keys

2-10. Each field may display the name of a menu or perform an operation

when the related menu key is pressed. The lowest field and related
Return push button (i0) are used to restore the higher menu level.

DISPLAY LAYOUT

Figure 4.1

Display Layout

4-1

4.2 Time and Frequency Field (II)

When the Marker cursor is activated by pressing push button (18), this

field displays the time difference between the Marker cross-hair and
the point of triggering (common for all displayed traces).

When the Time cursors are activated by pressing push button (17), two
readings are indicated. The left-hand reading indicates the time

interval between the Reference and Difference arrowhead cursors, while
the right-hand reading indicates the frequency corresponding to 1/(Time

interval).

Trigger Delay Field (III)

This field indicates one of the two trigger delay modes. In the
pre-trigger mode, an upward-pointing arrow appears below the bottom

line of the trace display grid, as shown in Figure 4.1. It is
adjustable from 0 to 10 divisions, corresponding to a 0 to 100Z
pre-trigger setting. In the post-trigger mode, this arrow is replaced
by a leftward-pointing arrow next to the post-trigger indication (in
decimal fractions of a second) at the bottom of the grid. The maximum
post-trigger setting corresponds to 10000 screen divisions.

4.4

4.5 Displayed Trace Field (V)

Abridged Front Panel Status Field (IV)

This is a short-form display of the data acquisition parameters, and is
updated whenever the 9400A’s front panel controls are manipulated. This

field indicates vertical sensitivities, input couplings, time base and

trigger conditions.

See Section 5 for a detailed list of front panel parameters (including

the absolute value of input offset).

The Displayed Trace field is associated with push buttons 45-50. The
data displayed in this field are the identity of the displayed trace,
and the current time base and sensitivity settings for the acquired
signal, as well as an indication of the position of the VAR sensitivity
vernier (28). The symbol ">" appears when the vernier is not in the
detent position (i.e. not in the fully clockwise position). Whenever
Measurement Cursors (16, 17, 18) are activated, absolute or relative

waveform voltage data are displayed in this field.

A frame formed around one of the upper six signal sources in the
Displayed Trace field indicates which of the traces is to be acted upon
during manipulation of the various display controls ((39) through (43).

Display Layout

4-2

4.6

Message Field (VI)

Messages appearing in field (Vl) indicate the 9400A’s current
acquisition status or report improper manipulation of the front panel

controls. The following figure illustrates a typical message displayed
in the Message field.

Channel 1

5~e 20mV

Channel 2

5~ .5 V

T/dlv 5~m 012 .5 V

Ch~ 20mV

~

Trig S.O8dtv+CHAN ~

EXAMPLE of MESSAGE FIELD DISPLAY

Figure 4.2

********

*NOTE*

********

In the following sections, Roman numerals in parentheses refer to the
display field numbering scheme in Figure 4.1. Arabic numerals relate to

the numbering scheme used to refer to front and rear panel controls and

connectors in Figures i.I and 1.2.

Display Layout

4-3

SECTION 5

MANUAL OPERATION

5.1

5.1.1 Vertical

Front-Pmlel Controls

Input Connectors (21) - BNC type connectors are used for both CHAN
and CHAN 2 signal inputs as well as the external trigger connector.
The maximum permissible input voltage is 250 V (DC + peak AC).

Signal Coupling and Input Impedance (22) - Selects the method used
couple a signal to the vertical amplifier input.

Possible selections: AC, GND, or DC with I M~ impedance

In the AC position, signals are coupled capacitively, thus blocking the
input signal’s DC component and limiting the lower signal frequencies

to < i0 Hz.

In the DC position, all signal frequency components are allowed to pass

through, and the input impedance may be chosen to be I M~ or 50 ~. The

user should note that with I M~ input impedance the bandwidth is
limited to I00 MHz. The maximum dissipation into 50 ~ is 0.5 W, and

signals will automatically be disconnected whenever this occurs. A
warning LED (OVERLD) lights when an overload condition is detected. The

input coupling LED (22) is simultaneously switched to GND. The overload
condition is reset by removing the signal from the input and selecting

a 50 ~ input impedance again.

DC with 50 ~ impedance

VOLTS/DIV (27) - Selects the vertical sensitivity factor in a 1-2-5

sequence. The sensitivity range is from 5 mV to 5 V/div at I M~ input

impedance and from 5 mV to I V/div at 50 ~ impedance (when the VAR

vernier (28) is in the detent position, i.e. turned fully clockwise).

Manual Operation

5-1

Menu

T/d:l.v .2jJ Ch2 .5 V ­Trlg .2O V - ~ =

DISPLAY of VERTICAL SENSITIVITY PARAMETERS

in the ABRIDGED PANEL STATUS FIELD

Figure 5.1

The VOLTS/DIV setting for CHAN 1 and CHAN 2 is displayed, along with
signal input coupling and various other data, in the Abridged Panel
Status Field (IV), see Figure 4.1. It may be modified either manually

or via remote control, and is immediately updated.

Whereas acquisition control settings displayed in the Abridged Panel
Status Field (IV) are immediately updated upon manual or remote modifi­cations of the VOLTS/DIV or TIME/DIV settings, the control settings in

the Displayed Trace field (V), corresponding to the conditions under

which the waveform was stored, are updated with every trigger.

C~’1 5mVll

I:h.....d. t

.IJ~ IluN

ChmrmL 2

.e~, v

T/dlv’JiOn.. Oh2 .2 Y ,,
Trl~i- .20V - EXT -

SENSITIVITY DATA DISPLAYED in the ABRIDGED PANEL

STATUS FIELD and in the DISPLAYED TRACE FIELD

Figure 5.2

5-2

.~L V~

Manual Operation

VAR (28) - Verniers provide continuously variable sensitivity within

the VOLTS/DIV settings and extend the maximum vertical sensitivity
factor to up to 12.5 V/div. Variable sensitivity settings are indicated
by the ">" symbol in the lower portion of the Abridged Front Panel
Status field and the calibrated value appears in the Total V/div field
of the Panel Status menu (See Section 5.2.2). (Minimum sensitivity
achieved by rotating the vernier counter-clockwise.)

VERTICAL OFFSET (32) - This control vertically positions the displayed

trace. The maximum offset is ± 1 grid height (± 8 divisions) from the
center of the screen, and is manually adjustable (or programmable)

0.04 division increments. A pair of upward- or downward-pointing
double-shaft arrows indicates when the trace has been positioned
outside the grid, as shown in Figure 5.3.

ir

w

UPWARD and DOWNWARD POINTING, DOUBLE SHAFT ARROWS

INDICATING THAT CHANNEL 1 and 2 ARE OFF SCREEN

Figure 5.3

PROBES - Two Model P9010 passive probes are supplied with the 9400A.

These probes have I0 M~ input impedance and 6 pF capacitance. The

system bandwidth with P9010 probes is DC to I00 MHz in 1M~ DC
coupling, and < I0 Hz to I00 MHz in AC coupling. Active FET probes

(Tektronix models P6201, P6202a and P6230) may be powered via probe

power connectors on the rear panel.

Manual Operation

5-3

PROBE CALIBRATION (19, 20) Tocal ibrate the P901 0 Prob e, conn ect it

to the CHAN 1 or CHAN 2 BNC connector (21). Connect the probe’s
grounding alligator clip to the front panel ground lug (20) of the
oscilloscope and the tip to lug (19).

Adjust the 9400A’s front panel controls as described in Section 8.1. In
case of over- or undershooting of the displayed signal, it is possible

to adjust the P9010 Probe by inserting the small screwdriver, supplied

with the probe package, into the trimmer on the probe’s barrel and

turning it clockwise or counter-clockwise to achieve an optimal square
wave contour.

BANDWIDTH LIMIT (50) Byset ting the BAND~rlDTH LIMI T butt on to O N t he
bandwidth can be reduced from 175 MHz to 30 MHz (-3 dB). Bandwidth

limiting may be useful in reducing signal and system noise or
preventing high-frequency aliasing for single-shot events at time bases
below 50 ~sec/division.

5.1.2 Time Base

TIME/DIVISION (36) This control se lects th e time pe r division in a

1-2-5 sequence from 2 nsec to 100 sec. The time base is displayed in
the Abridged Panel Status field (IV) as well as in the Displayed Trace

field (V). The time bas~ is crystal-controlled and features an overall

-~.

accuracy better than I0

SAMPLING MODES

Three sampling modes are possible with the 9400A depending on the

time-base setting selected by the user. They are:

Random Interleaved Sampling (RIS)

*

Single Shot (SS)

*
* Roll Mode

Random Interleaved Sampling (RIS)

At time-base settings from 2 to 20 nsec/div, the 9400A automatically
uses the RIS mode for signal acquisition. Repetitive waveforms and a
stable trigger are required. Waveforms can be digitized with sampling

intervals as small as 200 psec for an equivalent sampling rate of up
to 5 gigasamples/sec.

5-4

Manual Operation

Between the 50 nsec and 2 psec/div range of time base settings, the
user may select the RIS acquisition mode by pressing the INTERLEAVED

SAMPLING button (37).

Single Shot

For time base settings from 50 nsec to 200 msec/div the 9400A records

the waveform in a single acquisition. Sampling rates up to

i00 megasamples/sec are possible in the Single Shot mode.

Roll

From 500 msec to I00 sec/div, the 9400A samples continuously. Each
digitized point updates the display, resulting in a trace moving from
right to left similar to that produced by a strip-chart recorder.

TIME BASE

(TIME/DIV)

2.0 nsec

5.0 nsec

i0.0 nsec 200 psec

20.0 nsec 200 psec

50.0 nsec

0.I ~sec

0.2 ~sec

0.5 psec 200 psec i0.0 nsec 24000 500

1.0 psec 400 psec I0.0 nsec 24800 i000

2.0 ~sec

5.0 psec I0.0 nsec 5000

I0.0 psec i0.0 nsec i0000

20.0 psec I0.0 nsec 20000

50.0 Bsec

0.i msec

0.2 msec 80.0 nsec

0.5 msec

1.0 msec

2.0 msec 0.8 ~sec

5.0 msec

I0.0 msec

20.0 msec

50.0 msec 20.0 ~sec

0.I sec

0.2 sec 80.0 ~sec

SAMPLING RATE
TIME/POINT

RIS SS RIS SS

200 psec I00
200 psec 250 ---

200 psec I0.0 nsec 2500 50
200 psec I0.0 nsec 5000 I00
200 psec i0.0 nsec 10000 200

800 psec I0.0 nsec 25000 2000

20.0 nsec 25000

40.0 nsec

0.2 psec 25000

0.4 psec

2.0 psec

4.0 Hsec 25000

8.0 psec

40.0 psec

DISPLAYED RECORD

LENGTH (Points)*

500

I000

25000
25000

25000
25000
25000

25000
25000
25000
25000

5-5

Manual Operation

TIHE BASE

SA}4PLING RATE

TIME/POINT

DISPLAYED RECORD
I.RNCTH (Points)*

(TIME/DIV)

0.5 sec

1.0 sec

2.0 sec

5.0 sec

I0.0 sec

20.0 sec

50.0 sec

I00.0 sec ---

Note: When the 9400A is remotely read out, the entire memory content of

32,000 words is available at all time base speeds for single shot and
roll modes. 24,000 samples are available for all RIS settings except at

I and 2 psec/div, when 24,800 and 25,000 samples respectively are

available.

LIST of SAMPLING MODES, SAMPLING RATE,

RIS SS

ROLL NODE

0.2 msec

0.4 msec

0.8 msec

2.0 msec

4.0 msec

8.0 msec

20.0 msec

40.0 msec

and DISPLAYED RECORD LENGTH

Table 5.1

RIS SS

--- 25000

--- 25000

--- 25000
25000
25000

25000
25000
25000

5.1.3 Trigger

EXTERNAL Trigger Input (24) - This BNC connector input accepts

external trigger signal of up to 250 V (DC + peak AC). Input impedance
is 1M~ in parallel with < 30 pF. The triggering frequency is >200 MHz.

Trigger SOURCE (23) - Selects the trigger signal source as follows:

CHAN 1 - Selects the Channel i input signal.

CHAN 2 - Selects the Channel 2 input signal.

LINE - Selects the line voltage powering the oscilloscope in order

to provide a stable display of signals synchronous with the power

line.

Manual Operation

5-6

EXT - With the Trigger SOURCE set to EXT, a signal applied to the
BNC connector labeled EXTERNAL can be used to trigger the scope
within a range of ± 2 V.

EXT/IO - With the Trigger SOURCE set to EXT/10, a signal applied

to the BNC connector labeled EXTERNAL, can be used to trigger the

scope within a range of ± 20 V.

Trigger COUPLING (30) - Selects the type of signal coupling to the

trigger circuit:

AC Trigger - Signals are capacitively coupled; DC levels are

rejected and frequencies below 60 Hz are attenuated.

LF REJ - Signals are coupled via a capacitive high-pass filter
network. DC is rejected and signal frequencies below 50 kHz are
attenuated. The LF REJ trigger mode is used whenever triggering on
high frequencies is desired.

BF RBJ - Signals are DC-coupled to the trigger circuit and a
low-pass filter network attenuates frequencies above 50 kHz. The

HF REJ trigger mode is used when triggering on low frequencies is

desired.

DC - All of the signal’s frequency components are coupled to the

trigger circuit. This coupling mode is used in the case of high
frequency bursts, or where the use of AC coupling would shift the
effective trigger level.

Trigger

generate a trigger.

The trigger range is as follows:

SLOPE (25) Selects th e si gnal ed ge us ed to act ivate the

circuit.

LEVBL (33) - Adjusts the level of the signal required

± 5 screen divisions - with CHAN 1 or CHAN 2 as trigger source

None (zero-crossing) with LINE as trigger source

± 2 V with EXT as trigger source

± 20 V with EXT/IO as trigger source

POS - Requires a positive-going edge of the trigger signal.

trigger

NEG - Requires a negative-going edge.

5-7

Manual Operation

(POS/NEG) - Permits "window" triggering, i.e. triggering on either

a positive- or negative-going signal edge, whichever occurs first.

When the POS/NEG trigger slope is selected, the Trigger LEVEL
control (33) is turned counter-clOckwise for bi-slope triggering
at base line level. Turning the Trigger LEVEL control (33)

clockwise generates a variable amplitude trigger window which is

symmetrical with respect to the center of the screen (internal

trigger source) and to ground (external trigger source). When
using an internal trigger source, the user may produce an
asymmetrical window by offsetting the base line with respect to
ground via Vertical OFFSET control (32).

In the window triggering mode no trigger will occur while the
signal remains within the window. A signal which exceeds the

pre-selected limits will generate a trigger and the signal is
stored into the memory, as shown in the following figure.

Parml

STATUS

¯ M

WINDOW TRIGGERING

Figure 5.4

In the above figure the trigger level is ± 3 divisions as indicated in

the Abridged Panel Status field.

Manual Operation

5-8

Trigger MODE (29) - Selects the mode of trigger operation as follows:

SINGLE (HOLD) - Selected using the lower button (29).

In this mode the 9400A digitizes until a valid trigger is

received. After the waveform has been acquired and displayed, no
further signals can be acquired until the SINGLE (HOLD) button has

been pressed again to re-arm the trigger circuit in preparation

for the next trigger signal. This type of acquisition provides a
simple means of recording a wide variety of transient events.

When the 9400A is in the Random Interleaved Sampling (RIS) mode,

sufficient number of triggers must be obtained to complete

waveform reconstruction, after which the waveform will be
displayed. No further signals can be acquired until the SINGLE

(HOLD) button has been pressed again.

When the 9400A is in the Roll mode (~ 500 msec/div), pressing the

SINGLE (HOLD) button causes data acquisition to immediately halt
and the display to freeze.

NORM - Selected using button (29).

When in the normal (NORM) trigger mode, the 9400A continuously
digitizes the input signal. Whenever a valid trigger is received,

the acquired waveform is displayed on the CRT, digitization starts

again and the trigger circuit is re-armed. If no subsequent

trigger is received within 2 seconds, previously acquired

waveforms are erased from the screen. The absence of a valid

trigger will thus result in a blank screen.

To retain the last acquired waveform indefinitely in the NORM
mode, the 9400A’s Auto-store feature is used. Auto-store can be

called via the Special Modes menu described in Section 5.2.5.

When the 9400A is in the RIS mode, a sufficient number (typically

200) of valid triggers is required for each display of a complete

waveform.

In the Roll mode (~ 500 msec/div), the 9400A samples the input
signals continuously. Each point is immediately updated on the
display. This results in a trace which moves from right to left

across the CRT. In the NORM mode, triggers are ignored. The only
way to halt data acquisition is to select the SINGLE (HOLD) mode
or switch the 9400A into AUTO mode and provide a trigger.

Manual Operation

5-9

AUTO - Selected using button (29).

This mode resembles the NORM mode, except that it automatically
generates an internal trigger and forces a waveform to appear on

the screen whenever the selected trigger is not present for more
than 500 msec. When the 9400A auto-triggers, the display usually

moves in time as the trigger is not time-correlated with the input
signal.

Auto trigger can not be used when the 9400A is in the RIS mode.

When the 9400A is in the Roll mode (> 500 msec/div), it samples

input signals continuously. In the AUTO mode any valid trigger
will halt data acquisition once the trigger delay requirements
have been satisfied.

SEO_NCE - Selected using the upper button (29).

Sequence triggering enables the 9400A’s acquisition memories to be
partitioned into up to 250 segments.

Possible settings are: 8, 15, 31, 62, 125, or 250 segments.

Waveform acquisition in SEONCE mode is particularly useful in the
case of short-lived or echoed signals, such as those typically

encountered in RADAR, SONAR, LIDAR and NMR.

In this mode, the time base setting determines the total duration

(TIME/DIV x I0) of each segment. Changing the number of required
segments does not change the time base; it only affects the number
of digitized points (record length) per segment. The number
data points per division is shown in the Acquisition Parameters

display, called by pressing Panel STATUS button (2).

The display is only updated after a sufficient number of sweeps
has been acquired. If less than the required number of triggers is
available the SEQNCE acquisition may be aborted by pushing the
SEQNCE button (29) again.

The 9400A then completes the missing sweeps by auto-triggering a

sufficient number of times while setting its input coupling

temporarily to GND. Thus the artificially completed sweeps will
appear on the display as GND lines.

5-10

Manual Operation

Number of Segments Points/Seg~nent

8
15
31
62

125
250 I01

SEQUENCE TRIGGER MODE

NUMBER OF SEGMENTS VS. RECORD LENGTH (TIME BASE: 20 usec)

Table 5.2

Neither the CHAN 1 nor CHAN 2 display is updated when the 9400A is

in the SINGLE or SEQNCE trigger mode, i.e. when no further data
are acquired. Vertical positioning of the displayed trace may

nevertheless be modified via the OFFSET control (32). The VAR
vernier (28) also remains active. However, no other parameter

modifications, such as vertical sensitivity or time changes, will

alter the display of a currently acquired waveform in CHAN 1 or
CHAN 2.

Of course, all parameters may be modified during this time by
manipulating the appropriate front panel controls, but such
modification - indicated by parameter changes in the Abridged
Front Panel Status field (IV) - will only be used when acquiring

the next trace.

2501
2001
i001

497
241

Whenever the 9400A is in the NORM or AUTO trigger mode, data are
continuously acquired and the display rapidly updated. All
modifications in acquisition parameters are thus followed quickly
by subsequent waveform acquisition which results in their
appearing to the user as changes to the CHAN 1 or CHAN 2 display.

TRIG’D and READY LEDs (31) - The TRIG’D LED indicates Whenever the

digitizing has stopped (normally after a valid trigger). The READY LED
indicates that the trigger circuit has been armed and the 9400A is
currently digitizing input signals. Upon receiving a valid trigger
signal, it will continue digitization until the trigger conditions have
been satisfied and will then display the acquired waveform.

DELAY (34) - Adjusts the degree of pre- or post-trigger delay when

recording signals in the acquisition memories. Delay operation is via a
single continuously rotating knob. Turning this knob slowly allows

minute adjustment of the trigger point; turning it quickly results in

rapid trigger point movement. The DELAY control enables pre-trigger
adjustment, displayed in %. Pre-trigger adjustment up to 100% full
scale, and post-trigger adjustment up to i0,000 divisions in 0.02

division increments are available.

Manual Operation

5-11

The pre-trigger indicator is displayed by an upward pointing arrow on

the bottom graticule line; the post-trigger indicator is displayed in

decimal fractions of a second, preceded by a leftward-pointing arrow,

in the left-hand corner of the Trigger Delay field (III).

ZERO (35) - Resets the trigger delay from previously set positions

the leftmost graticule line (i.e. 0.0% Pre-trigger position).

5.1.4 Displaying Traces

Up to four different waveforms (out of a total of eight) may

simultaneously displayed. Whenever a trace is displayed by pressing one

of the TRACE ON/OFF buttons ((46)-(49)), the corresponding waveform
will appear on the screen together with a short description in the

Displayed Trace field (V). When several signals are being displayed

simultaneously, buttons (46)-(49) can be used as convenient trace

identifiers by repeatedly pressing one of these buttons and simply

seeing which of the displayed traces is turned ON and OFF by this

operation.

EXPAND A, B buttons (46) - Turn the displayed expansion of a waveform

ON or OFF. The expanded portion of the waveform is displayed on the

source trace as an intensified region. The default settings are;
EXPAND A operates on CHANNEL 1 and EXPAND B operates on CHANNEL 2. They

may be changed to allow expansion on any other source trace, by using

the REDEFINE button (48).

MEMORY C, D buttons (47) - Turn the display of a waveform in reference
Memories C or D ON or OFF. Acquired data may be stored into these
memories via the STORE button (I), as described in Section 5.2.1.

FUNCTION E, F buttons (48) - If your 9400A is equipped with a waveform

processing firmware option, pressing these buttons will turn the
display of a computed waveform ON or OFF. The type of computation may

be defined by pressing the REDEFINE button (45). See WPOI Waveform
Processing Option, Section I0.

CHANNEL I, 2 buttons (49) - Turn the display of signals applied
either of the input connectors (21) ON or OFF. Recording of data into

CHAN 1 and CHAN 2 acquisition memories always occurs simultaneously and

irrespective of whether the trace display is ON or OFF.

5.1.5 Display Control

Displayed traces may be modified within certain limits following
waveform acquisition.

CHAN 1 and CtlAN 2 traces are controlled by the VERTICAL and Time

The

Base controls ((27), (28), (32) and (36), (37), respectively).

5-12

Manual Operation

Six traces, EXPAND A, B (46), MEMORY C, D (47), and FUNCTION E, F
are controlled by the Display Control knobs and buttons (39)-(45).

one trace is controllable at a time. The identity of the controlled

trace is indicated by a rectangular frame around the waveform

descriptor in the Displayed Trace field (V).

Whenever more than one of the six traces listed above are currently

displayed, the frame may be moved to the next trace by pressing the
SELECT button (44).

Horizontal POSITION knob (39) - Horizontally positions an expanded

waveform and the intensified region along the source trace. This

control is activated only after the EXPAND A and/or B buttons (46) have
been pressed to display the expanded trace. The Horizontal POSITION
knob allows the user to scroll continuously through a displayed

waveform. However, if the source trace was recorded in sequence mode

(i.e. a number of sequentially acquired traces was stored in
partitioned memory blocks), the movement of the Horizontal POSITION
knob will be discrete allowing any single segment to be selected.

The Horizontal POSITION control affects only EXPAND A, B.

Vertical POSITION knob (40) - Vertically repositions the trace.

RESET button (41) - Serves to reset previously adjusted VERT GAIN,
Vertical and/or Horizontal POSITION to the following default values:

VERT GAIN

Vertical POSITION

Horizontal POSITION

In the Common Expand mode (See Section 5.2.5.2), this button is used

synchronize the two intensified regions of EXPAND A and B.

VERT GAIN knob (42) - Turning the knob clockwise allows vertical

expansion by a factor of up to 2.5. Counterclockwise rotation allows

vertical contraction by a factor of up to 2.5. If the vernier knob is
not in the detent position it is possible to achieve vertical expansion

by a factor of up to 5.

Pressing RESET (41) returns gain control to a mid-range plateau
corresponding to a gain of I. If the 9400A is equipped with WP01, the

vertical gain is increased from 2.5 to I0 for averages, mathematics and

functions.

Same as the original trace

-

Same as the original trace

-

- Center of the original trace

5-13

Manual Operation

TIME MAGNIFIER knob (43) - This control horizontally expands waveforms
up to I00 times.

Overall timing accuracy is improved at higher magnification factors,
since the expand function is controlled digitally and makes use of the

scope’s high number of recorded data points. This control has no effect
on MEMORY C, D or FUNCTION E, F.

SELECT button (44) - Chooses one of the traces - EXPAND A through
FUNCTION F - to be controlled via Display Control knobs and buttons

((39)-(45)). The selected trace is indicated by a rectangular
around the waveform descriptor in the Displayed Trace field (V).
Pressing the SELECT button (44) moves the rectangle to the next
displayed trace in a rolling sequence.

REDEFINE button (45) - Used to redefine the identity of the selected
waveform. EXPAND A, B traces may be redefined to be the expansion of
CHAN 1 or CHAN 2, MEMORY C or D or FUNCTION E or F (for 9400A’s

equipped with the Waveform Processing Option).

Pressing the REDEFINE button (45) calls a menu on the left-hand side

the screen enabling selection of the desired source redefinition. When

the button corresponding to this redefinition is pressed, EXPAND A or B
will be temporarily selected as the new source trace until subsequent

redefinition is performed. The default signal sources are CBAN I for
EXPAND A and CHAN 2 for EXPAND B.

It is not possible to redefine Memories C and D; Function E and F may
only be redefined if your 9400A is equipped with the Waveform

Processing Option. For scopes with this option installed, see Section

l0 which deals with the Waveform Processing Option.

5.1.6 Screen Adjustments

INTENSITY knob (12) - Adjusts the intensity of the displayed trace and

all alphanumeric readouts and messages. The INTENSITY control may be

adjusted in either manual or remote control mode.

GRID INTENSITY knob (13) - Controls grid and graticule intensity

independently of displayed trace intensity.

DUAL GRID button (14) - This button switches between single and dual
grid modes. The dual grid is useful when displaying multiple traces, in
which case the CHAN I display is permanently assigned to the upper grid
and CBAN 2 to the lower grid. All other displayed traces may be

repositioned anywhere on the screen via the Vertical POSITION control

(4O).

5-14

Manual Operation

SCREEN DUMP button (II) - Dumps the contents of the screen to

on-line digital plotter via the 9400A’s rear panel RS-232-C interface

port or optional GPIB port to provide color or monochrome hard copy

archiving of the display. All of the screen illustrations included in

this manual were produced using the SCREEN DUMP function.

5.1.7 Cursors

Cursor measurements can be made simultaneously on up to 4 traces on the
9400A’s CRT.

HARKER Cursor button (18) - Pressing this button generates a

cross-hair marker for precise time measurements relative to the point
of triggering, as well as absolute voltage measurements along the
displayed waveform irrespective of the vertical offset of the trace
displayed on the grid.

Note that setting the marker cursor to 0 time interval provides a
visual indication of the trigger point.

r

/

/ \

/

\

!

!
I

I

DISPLAYED TRACES SHOWING MARKER CURSOR,

INTERVAL BETWEEN TRIGGER POINT and CURSOR, as

well as ALPHANUMERIC READOUT of the AMPLITUDE of the TRACES

/ \

/ \ ! \

f

/

/ \

/

I ."-- -

: ." : i :

. ,

.. .

I I I "

i Y_i

v

i-i-l

. , . : :

I I .-

..

!!- :

i ,

J i,+--

/ \

/ \

\

’+-

..

:

.

: ~). 1.

-4.2 mY

l,.

Channel 2

.2mV

T/dlv .Snm Ch2 20mY ffi

Trig .00 dlv + CHN~ 1"

Ch 1>.2 V

~

Figure 5.5

5-15

Manual Operation

TIME Cursors button (17) - Generate a downward-polnting and
upward-pointing arrow on the currently displayed traces, permitting
accurate differential time, voltage and frequency measurements. Time
cursors are displayed as follows:

Maln
M~u

A

#

.... j---l-

/

,7 .....t .......

.7 .......

I .....7

/ t /

.... 1 ...... -’~-/-i

At 1.78,m F 588.1Hz

DISPLAYED TRACE SHOWING TIME CURSORS,

their VOLTAGE DIFFERENCE their TIME DIFFERENCES

and the CORRESPONDING FREQUENCY.

/,.k

-~

-i-i::-\- ~ ......

,! t /

! ....../ ........t, .....

E1 .....f

I,,,

p

l

........

t-

/" t

iii iii i

....... t ChannQ1 1

T/div .5ms Ch2 20mY =
Trig .00 dlv + CHN~ ~.~

Ii i

t

Jig mV

Ch I.>.2 V

~

Figure 5.6

Note: Measurement resolution with Time cursors is 0.2Z of full scale

(I0 divisions).

In the case of expanded traces, time cursors are displayed on the
trace, providing up to ×100 higher resolution measurement (0.002E

maximum, depending on the setting of TIME MAGNIFIER control(43)).

Use of the waveform expansion facility is therefore recommended to
ensure the most accurate time measurements.

Manual Operation

5-16

VOLTAGE Cursors button (16) - Generates two linear cursor bars which
provide accurate differential voltage measurements when adjusted

vertically on the currently displayed waveform. The REFERENCE and
DIFFERENCE controls (38) serve to position the Reference and the

Difference cursor bars.

Voltage cursor bars are displayed as follows:

R

A .....A ........

A A A

-I~ -I-I ......-I~ ......

II I~ I

.... , ....I...~... I... ~...

1’ .... / ....... \

....

~ll \J

.... ~ .......

.... i::--V- --V

V-

DISPLAYED TRACE SHOWING REFERENCE and DIFFERENCE VOLTAGE

CURSORS, and ALPHANUMERIC READOUT of TRACE AMPLITUDE

Figure 5.7

¯

~

......

.I. I-

T/oiLy .2me Ch2 2C)mV

Tr’J.o .CX) dlv÷ CHNq 1

V

Q14.>.2 V "

Note that measurement resolution with the VOLTAGE cursors is 0.2% of

full scale (8 divisions).

CURSOR POSITIONING knobs (38) - In the
cursors, the REFEP~NCE control adjusts the

cursor to the point used as measurement reference. The DIFFERENCE
control is then adjusted to move the Difference cursor to the desired
position

The + Marker cursor is moved along the displayed waveform by means of

the REFERENCE cursor positioning knob alone.

Pressing the TRACKING button causes the Difference cursor to track the

Reference cursor at a fixed interval as determined by the DIFFERENCE

control (in the case of Voltage and Time cursors).

along the trace.

5-17

case of Time and Voltage

Time and Voltage Reference

Manual Operation

5.2 Menu Controls

After the Main Menu key (2) has been pressed, any one of the 9400A’s
interactive menus may be selected by pressing buttons (2)-(10). Figure

5.8 shows the available menus as they appear on the 9400A. To obtain a

given menu, press the button adjacent to the menu desired.

Isls ¯
,,,. ,,,,|,,,, ,,,,|,,,,,,,,,.,,,,|,,,,l,,,,a,,,,,

5.2.1 Store Menu

Using the STORE button (I), it is possible
the waveforms currently in the 9400A’s
reference Memories C and/or D.

To store the currently acquired waveform, first stop the acquisition by
pressing the SINGLE (HOLD) button (29). Once acquisition has stopped,

press button (I) and respond to the messages displayed to the left

the screen. The options are shown in Figure 5.9.

T/dlv. 2 nil Ch 2
TrJ.g .20 cllv - CHN~ t :

9400A Main Menu and RELATED MENU KEYS

Figure 5.8

to store either or both of

acquisition memories into

5-18

Manual Operation

St, ore
Trooe

1 ->

HImC

Ch~2 ->
FunoE->

HmC

Funo F ->
Chon 1. ->

HImD

Chart2 ->
FunoE ->

I’kmD

Funo F ->
Ret, ul-n/

Conoel

STORE TRACE MENU

Figure 5.9

T/dtv .2me Ch250mV
TPLQ

Chl 50mY I

-- +LINE .

Pressing buttons (2), (3), (6) or (7) causes an identical copy
displayed waveform (or waveforms) to be stored into reference Memories
C and/or D.

If acquisition is taking place when the store button (I) is pressed,

the user is prompted with the message:

STOP

ACQUISITION IN ORDER TO STORE

Manual Operation

5-19

5.2.2 Panel Status Menu

The Panel Status menu provides a complete report of front panel control
settings and permits on-screen adjustment of acquisition parameters.

PLOTTING

PANEL STATUS MENU

Figure 5.10

Vertical parameters:

Fixed V/dtv

The current setting of the front panel Vertical Sensitivity
control (27) with the VAR vernier in the fully clockwise position

is indicated.

Total V/div

The current setting of the front panel Vertical Sensitivity
control (27) plus the additional sensitivity range (up to x 2.5

the Fixed V/div setting) is provided by turning the VAR vernier
(28) counterclockwise.

5-20

Manual Operation

Trigger parameters:

Delay

In Figure 5.10 the indicated trigger delay is 10% Pre, meaning

that when in Main Menu the Delay arrow is positioned one division
to the left of the center of the grid. In the case of a
post-trigger delay setting9 this would be indicated in decimal

fractions of a second (i.e. + 4.00 msec).

Level

The trigger level indicated in Figure 5.10 is displayed in terms

of grid divisions. The 9400A displays the current trigger level
setting in divisions when in the internal trigger mode. It
displays the setting in Volts when in the external trigger mode.

Time/point

Indicates the time between digitized points for the corresponding

time base setting.

Points/div

This parameter indicates the number of digitized
division on any non-expanded waveforms displayed.

# Segments for SEQNCE

This parameter indicates the number of segments selected for
sequential acquisition. On-screen modification of this parameter

is possible by pressing the Modify # Segments button (4) to change
the indicated segment number from 8 to 250 in a rolling sequence.

Set CHAN 1 Attenuator (6) and set CHAN 2 Attenuator (7)

allow the user to enter probe attenuation factors of I0, i00 and

I000.

Press the Return key (10) to list the available menus.

For information concerning the other parameters displayed on the Panel
Status menu, see Section 5.1.

points per

5-21

Manual Operation

5.2.3 Memory Status

The Panel Status menu displays acquisition parameters for waveforms to
be acquired after receiving a trigger signal. On the other hand, the

Memory Status menu displays all acquisition parameters for waveforms

currently stored in the various memories of the 9400A.

The annotation used for Memory Status is similar to that of the Panel

Status menu. Pressing the Memory Status button (3) displays the Memory
Status menu in Figure 5.11.

ItDtORY STATUS

Ch t+2

STATUS

llk~ GI.D

STATUS

r

Fun £~1

PLOTTII~

Pressing button (2), (3) or (4) while in the memory status menu
display the acquisition parameters of waveforms stored in acquisition,

expansion and storage memories respectively.

To¢.ol V/dlv
OPP~#. .0 mV

Coupltr~-LLml~, ~ t HO, 0:1=

Time (F’meq)/dlv

TO:’|lpr~ + ~d.tv ~00 rm, ~

TrLg-Deloy 9.8X Pre
Tr-I.m~l + Slq:~ .OOcRv, +

Tr~_~i-__.-~e ÷ Ca:x~ 04AN 1, DC
I1mory LIIt~

Rm}or’d-Type SINi~

MEMORY STATUS CHAN 1 and CHAN 2

Figure 5.11

EJO.O mV

.5 me

-~)00,2E(X)O

150.0 mY
.0 mV

AC 1 HI}, OFF

.5 me

200 I’m, 2500

9.8X Pr~

CHAN ~, []C

-;~X), 2EO00

5INIEE

v 2,0OFT

.OOcRv, +

5-22

Manual Operation

Ch t+2

STATUS

F~p~m

l~m Gto

STATUS

Fun E+F

Plmory C
50O IV

4000 mV
13(3600, OFF

.2mo

80rm, 2500

.4Z I:Me

LINE , 13C

0,26000

SINGLE

A~Cl)

t252, 20

5

V 2.08FT

~mory o

50.0 mV
.OmV

DOEO O, OFF

.Eme

200 no, 2500

.OX Pre

-20.0 V , -

EXT/IO, DC

-~000,260(X)
5INGLE

Ch t+2

STATUS

~xp A+8

I~mC+D

STATUS

E+F

Fun

PLOTTING

TRACE A,

ItEI’IORY STATUS

B EXPAND STATUS MENU

Figure 5.12

MEMORY STATUS C and D

Mmmry C
5OO iiV

4000 mV
DCEO O, OFF

.2mo

80rm, L:~O0

.4Z I:Me

LXHE , 13C

0,26000

5[NGI.[

A~(l)

t252,20

1

V 2.08FT

Hm.ory D

50.OmV
.OmV

DCEO 0, OFF

.6me

2CX3 rm, 2500

.OX Pre

-20.OV , -

E~T/tO, OC

-7(XX),26000
5INGLE

Figure 5.13

5-23

Manual Operation

The indication in the upper right-hand corner of Figures 5.12, 5.13,

5.14 corresponds to the software version implemented in the scope.

5.2.4 Storage and Recall of Front Panel Setups

Pressing the Store PANEL or Recall PANEL buttons ((4) and (5),
respectively) enables storage or recall of up to seven different front

panel acquisition parameter settings.

SP~m’e
Parml

-> Pa’ml 5
STORE

-> I%:’ml 2

-> I::-ml 9
STORE

,,,, ........

:::.::::.::::,

-> I:(a’ml 4 ..........................

-> I:m-ml 5

STORE

-> Pa-ml 8

-> I:onel 7

STCI~

Return

STORE and RECALL FRONT PANEL SETUP MENUS

Figure 5.14

Once you have obtained a satisfactory front panel setup, simply call

the Store PANEL menu by pressing button (4); then press any one of the

buttons (2) through (8) to store this front panel setup where required.
Press the Return button (10) to go back to the Main Menu and continue

normal scope operation.

5-24

Manual Operation

To recall a previously stored front panel setup, press the Recall PANEL

button (5) while in the Main Menu. A list of the seven stored front
panel setups which are available will be displayed. Press the button

((2) through (8)) which corresponds to the desired setup, and the
panel settings will automatically be configured according to the
acquisition parameters recalled.

5.2.5 Special Nodes (7)

AUTO-STORE OFF

In ~ and AUTO, the oeollloeoope moy be Por-o~ to

o,k~mc~loolly etxx,e one or both ~tm’lnell In olt,~’me
mmory C or O oPtm, p.j.m ooqutmltton o4’ ~¢h tKMB-

Mod. Common

POP,,. lhJ.m modw wLo~ down tim dJ.mplay rq:m~lt;lon
r’~be, ell’me a ~ opm-c~ion t.d¢~ oe much as 200 me.

COPItON E~N~D OFF

ktwn ON, the hoplzont~l poeitlan and time .mgnlFler
oor~roi knd:e ao~ on both expandmd tPoo~ A AND B
PoP o olmult~neoue horizontal ooan. The vertloal
arxJ paml~lon remain Indivldua11y aor~rolled.

¯ :q~IAL MODES

Return

PLOTTING

5.2.5.1 Auto-store Mode

Pressing the Special Modes button (7) while in the Main Menu allows the
user to automatically store - following acquisition - CHAN I or CHAN 2

into the unit’s two reference memories.

Pressing the Modify Auto-store button (2) allows the user to choose

from among the following possible storage modes: CHAN I into Memory C

or D; CHAN 2 into Memory C or D, or, alternatively, CHAN I into Memory
C and CHAN 2 into Memory D.

SPECIAL MODES MENU

Figure 5.15

Manual Operation

5-25

This is a useful feature for very low repetition rate signals acquired

in the NORMAL trigger mode. Subsequent display of the selected
reference memory provides the user with a lasting waveform display
which can be studied long after the originally acquired signal has been
erased. In the NORMAL trigger mode the CHAN 1 and CHAN 2 displays are

automatically erased after a two second interval to warn the user that
a proper trigger is not available.

5.2.5.2 Common Expand Mode

Section 5.1.4 discusses independent expansion of single traces to
display a magnified portion of the waveform from CHAN 1 and/or CHAN 2,
Memories C and/or D, or of Function E and/or F if the 9400A is equipped
with WPOI Waveform Processing firmware. However, in certain
applications, it is convenient to be able to move the intensified

region along two different traces simultaneously. This is the purpose
of the Common Expand mode.

In this mode it is possible to either synchronize the intensified

regions of the two source signals, or to maintain a fixed time interval
between them, in which case the intensified regions for each trace will

move horizontally at a fixed interval. (See Section 8.11 for an example
of intensified regions shifting on two traces expanded in the Common
Expand mode).

In the Common Expand mode, when the user is examining two expansions at
a fixed interval (he may re-synchronize them by pressing the RESET
button (41)) both expansions are shifted to the center of the grid.
Turning the Horizontal POSITION control (39) until both of the

intensified regions move off the screen will also re-synchronize them.

In the Common Expand mode, only the Horizontal POSITION control (39)
and TIME MAGNIFIER control (43) act simultaneously on the intensified
regions on both the EXPAND A and B signal source, while the VERT GAIN
control (42) and Vertical POSITION control (40) act independently
each expanded waveform.

Note that when the Common Expand mode is called,
magnification factor applies to both A and B expansion.

5.2.6 RS-232-C Setup (8)

Two RS-232-C ports are available on the rear panel of the 9400A

permitting remote oscilloscope operation and data transfer, as well as
convenient plotter interfacing.

the EXPAND A

5-26

Manual Operation

When in the main menu, pressing RS-232-C SETUP button (8) calls

interactive menu enabling configuration of both of the 9400A’s RS-232-C
ports for a particular application. Parameters for the
plotter-dedicated RS-232-C port (57) are displayed in the lower portion
of the screen, while those for the remote RS-232-C port (56) are
presented in the upper portion of the screen.

RS~32 - RemOte c~nbrol port

Saud r’~e: !~

C~ro~er Length Cblt6):

Parity: norm

Number oF stop bits: I

I~wioue

VALUE

Nex~

To modify any of the parameters displayed, first select the field to be

modified. The rectangular frame around parameter values indicates the

currently selected field. Pressing the Previous FIELD button (2) will

cause the frame to move towards the top of the list, whereas pressing

the Next FIELD button (3) will move the frame downwards.

Following field selection, the current value of the field may be

modified by pressing either the Previous (6) or Next VALUE (7).

Baud rate is selected from a set of values in the range ii0 through

19,200 baud. The possible settings of character length are 6, 7, and 8;
parity, none, even or odd; and number of stop bits, I and 2.

RS232 - Plotter port

Baud rate: 9600
Charooter Length Cblt~):

Parity: none

Number oP etop bite: I

RS-232-C SETUP MENU

Figure 5.16

5-27

Manual Operation

5.2.7 Plotter Setup (9)

The 9400A has been designed to permit direct interfacing of the
oscilloscope with four of the most popular plotters via the rear panel

RS-232-C dedicated plotter port or the optional GPIB (IEEE-488) port.

When the 9400A is connected to a plotter via the GPIB port, with no
host computer in the configuration, the oscilloscope’s rear panel

thumb-wheel switch must be set to the Talk Only mode (address > 31

decimal) and the plotter to the Listen Only mode.

Plotter setup configuration is similar to configuration of the RS-232-C

ports (see Section 5.2.6 above).

PLOTTER

Plobt~w’: IHE~-ETT PACKARD 7+70A om oompob~hlol
Plobbem pore: RS292
Plob speed: NORHN.

PPovlouo

VALUE

Next;

Reb~Pn

PLOTTING

NuMbem oF Installed pane: Z

PLOT SIZE

Popem eLze: A4 (ISO) - USIt°/8.5"

The plot; amea w111 be 1~ bhon: 22gram ¯ 1BO~

PLOTTER SET-UP MENU

Figure 5.17

5-28

Manual Operation

The user can choose the following parameters:

Plotter Type:

Plotter Port:

Plot Speed:

Number of
Installed Pens: I to9

Plot Size:

Non-standard: In the case of non-standard paper sizes, the size of

* If GPIB is selected by no GPIB board is installed (basic 9400A), the

instrument may lock up when the screen dump button is pressed.

HP7470A (or compatible), Philips PM8151

(or compatible),Tektronix or Graphtec FP 5301

RS-232-C or GPIB (IEEE-488)

Normal or Low Speed

ISO A5 (US 8.5" x 5.5"), ISO A4 (US ii"

8.5"),IS0 A3 (US 17" x ii") or non-standard

the grid square can be chosen between 0 to 99.9 mm in

0.I mm steps; lower left corner position from 0 to
999 mm (for both X and Y coordinates) in I mm steps.

5-29

Manual Operation

SECTION 6

REAR PANEL CONTROLS AND CONNECTORS

6.1

6.2

6.3

Fuse Protection

The power supply of the 9400A is protected against short circuits and
overload by means of a T(slow) 1.6/ 250 V fuse for units which can
operate on 220 V or 115 V mains voltage (switch selected) or a T (slow)

3.15/ 250 V fuse for units operating only on 115 V mains voltage. The
fuse is located under the 115 to 220 V mains voltage selector drum

cover.

Accessory Power Connectors (51)

Two LEMO RA 0304 NYL connectors have been provided to permit use of FET

type probes with the 9400A. These connectors provide output voltages of

+ 5 V, ± 15 V and GND connection, suitable for most FET probes.

The

maximum output current per connector must be limited to 150 mA for

each of the three voltages.

Battery Pack (52)

The battery pack consists of two KR 15/51, 1.2 V rechargeable NiCd
batteries enabling retention of front-panel setups for 6 months in case

of power failure or whenever the 9400A is switched off. The battery
pack is automatically recharged during operation.

6.4

The battery pack can be accessed by pressing the plastic latch at the

top of the cover and pulling it downward and toward the user.

GPIB and RS-232-C Port Selection (54)

The 9400A’s rear panel thumbwheel switch is used to set addresses for

programmed or remote oscilloscope operation. Any one of addresses 31-99
selects the RS-232-C port. Addresses 0-30 define the 9400A’s address

when using the optional GPIB (IEEE-488) port.

GPIB

panel next to each connector.

and RS-232-C pin assignments are clearly indicated on the rear

Rear Panel Controls and Connectors

6-1

6.5 Plotter Connector (57)

In addition to the RS-232-C port (56) used for remote 9400A operation,
a second RS-232-C port (57) has been incorporated to facilitate direct
interfacing of the 9400A with a digital plotter. Plotters are used for
hard copy archiving of displayed waveforms and other screen data. Pin
assignments for the plotter connector are identical to those of the

remote RS-232-C port (56).

While a plotter unit connected to the 9400A’s RS-232-C port can be
computer controlled from a host computer via the optional GPIB port,

the oscilloscope’s on-board digital plotter drivers permit hard copies
to be made without an external computer.

Plotter connector pin assignments:

Pin #

2 T x D

3 RxD
4 RTS
5 CTS

20 DTR

6 DSR

1 GND

7 SIG GND

This corresponds to a DTE (Data Terminal Equipment) configuration.

Description

Transmitted Data (from the 9400A)
Received Data (to the 9400A)
Request To Send (always on) (from the 9400A)
Clear To Send (to the 9400A)
When TRUE, the 9400A can transmit.

When FALSE, transmission stops.
Used for 9400A output hardware handshake.
Data Terminal Ready (from the 9400A)
Always TRUE.
Data Set Ready (to the 9400A)
Protective Ground
Signal Ground

6-2

Rear Panel Controls and Connectors

SECTION 7

REMOTE OPERATIONS

7.1

Progr.mmed Control

Most of the front panel and internal functions of the 9400A can be

remotely controlled using a set of high-level, English-like commands
and mnemonics. For example, a command followed by <?> tells the scope

to transfer to the host computer the value of the control setting
defined by the command. It is thus possible to read the complete status
of the instrument by repeated queries. It is also possible to save the
entire status of the instrument in binary format with a single command.

The 9400A’s remote control facility allows complex measurement

procedures and instrument setups, a particularly useful feature in
experimental and automated testing environments.

The 9400A can be programmed via the rear panel RS-232-C port interfaced
with a computer terminal or a computer. Remote control is also possible
via GPIB (IEEE-488 bus) if the 9400A has been fitted with the option
OP02. In this case data transfer rates are relatively faster.

To help users who wish to remotely control the Models 9400 (125 MHz
bandwidth) and 9400A (175 MHz bandwidth) oscilloscopes, LeCroy have

published the following application notes which are available on
request:

ITI 002: Linking the LeCroy 9400 to an IBMR PC-AT via the RS-232-C

Asynchronous Interface.

ITI 005: Linking the LeCroy 9400 to an IBM PC-AT via GPIB.
ITI 006: Linking the LeCroy 9400 to an HP 9000 Model 216 controller.

7.2 RS-232-C Ports (56 and 57)

The 9400A has two RS-232-C ports. One is available for computer or

terminal controlled oscilloscope operation, the other for plotter

interfacing. The RS-232-C ports provide an asynchronous data transfer

rate of up to 19,200 baud.

Remote Operations

7-1

RS-232-C Pin Assignments

The remote RS-232-C pin Assignments (indicated on the rear panel) are
as follows:

Pin #

2 TxD

RxD

3

RTS

4

5 CTS

2O DTR

DSR

6

GND

1

SIG GND

7

This corresponds to a DTE (Data Terminal Equipment) configuration.

Although descriptions vary slightly, pin assignments for the dedicated

plotter interface (Section 6.6) are identical to those for the remote

RS-232-C connector above.

Description

Transmitted Data (from the 9400A)
Received Data (to the 9400A)

Request To Send (always on) (from the 9400A)
Clear To Send (to the 9400A)

When TRUE, the 9400A can transmit.
When FALSE, transmission stops.

It is used for the 9400A output hardware handshake.

Data terminal ready (from 9400A). If the software

Xon/Xoff handshake is selected it is always TRUE.
Otherwise (hardware handshake) it is TRUE when the

9400A is able to receive characters and FALSE when the
9400A is unable to receive characters.

Data Set Ready (to the 9400A)
Protective Ground
Signal Ground

7.3

GPIB Port (Option OP02 only) (55)

The 9400A’s GPIB interface (optional) complies with IEEE-488 (1978)
standards, and is intended to provide high-speed data transfer in

either the ASCII or binary format between the 9400A and the computer to
which it is interfaced. The maximum data transfer rate, depending on

the controller used, may be as high as 400 kilobytes/sec.

GPIB Port Selection (54)

As mentioned in Section 6.5, the 9400A’s rear panel thumbwheel switch

is used to set addresses for programmed or remote oscilloscope

operation. Addresses 0-30 define the 9400A’s address when using the
GPIB (IEEE-488) port; using any one of addresses 31-99 selects the
RS-232-C port. The thumbwheel is read at power ON only. Whenever the
GPIB address is changed, the power must be turned off and on again.

GPIB functions are clearly indicated on the rear panel next to the GPIB
connector.

Remote Operations

7-2

GPIB Functions

The following is a list of the various functions
9400A’s rear panel GPIB connector:

AHI

SHI

L4

T5

SRI
RL2
DCI

DTI

PP1

CO
E2

7.4

7.4.1 Introduction

GPIB and RS-232-C Command Format

All the remote control commands apply equally to communication via the
GPIB and RS-232-C ports. (Note that GPIB commands should not be used
when Option 0P02 is not fitted in the 9400A.) Certain functions,

however, which are part of the GPIB standard (such as Device Clear or
Group Execute Trigger) must be implemented as separate commands for the
RS-232-C interface (see Section 7.6.10). The command syntax

compatible with IEEE Recommended Practice for Code and Format

Conventions (IEEE Standard 728-1982).

provided via the

Complete Acceptor Handshake
Complete Source Handshake

Partial Listener Function

Complete Talker Function
Complete Service Request Function

Partial Remote/Local Function
Complete Device Clear Function

Complete Device Trigger
Parallel Polling: remote configuration
No Controller Functions
Tri-state Drivers

In GPIB, the predefined control commands, such as Device Clear, Group

Execute Trigger, Set Remote or Set Local, are part of the device driver

commands. Therefore the 9400A only has English-like commands for these
functions in RS-232-C inferfacing applications. The user must consult

the manual for his GPIB-interface driver in order to determine the form

of these special commands.

Commands are formed of easy-to-read, unambiguous English words, with
abbreviations (typically 2 to 4 characters) being used to achieve
higher throughput. Short and long formats may be freely substituted for
one another.

The execution of certain commands depends on whether the 9400A is in

the REMOTE or LOCAL state.

Remote Operations

7-3

When the 9400A is in LOCAL:

- All the front panel controls are active.
Reading the 9400A by remote control is possible.

-

- The status byte masks (see MASK command) and the communications

protocol (see COMM command) may be written, status bytes may
cleared.

When the 9400A is in REMOTE:

All the front-panel controls are deactivated, except the two

-

display intensity controls and the left-hand side menu buttons.

- All the remote commands are executed.

- A special command (SCREEN) exists to deactivate the front panel

display intensity controls and allows them to be set remotely.

7.4.2 Compound Commands

One or several commands can be sent to the 9400A in a message ending

with <END>. In GPIB transfers, <END> is the line which marks the EOI

(End of Information). In this case, <END> is <;>,<CR> or <LF>.

RS-232-C transfers, <END> is a user-selectable string; the default is
<CR>.

Where multiple commands are used to compose a message, each command is
separated from the following one with a <;>, a <CR> or a <LF> or with
any combination of these characters.

Example:

TRIG SLOPE POS; TIME/DIV 50 NS <END>

represents 2 commands where <;> is used to separate them.

Commands are executed only after <END> is received. Exceptions to this

rule are mentioned later (see Section 7.4.6).

7.4.3 Command Format

Simple commands consist of a header, indicating the desired operation.

The header is usually followed by one or more parameters used to

describe the desired operation in greater detail.

HEADER (<SPACE>, <,> or <=>) Parameter i, Parameter 2, etc.

7-4

Remote Operations

The header may be separated from Parameter 1 by either a space, comma,

equals sign or any combination of these. Parameters MUST be separated
from one another using a comma.

Headers and key-word parameters may be transmitted using either the
full or an abridged format. Both upper and lower case characters are

valid and may be used interchangeably.

Numbers must be in accordance with ANSI X3.42-1975 standards and may be

transmitted as integers, or in scientific notation, with or without

exponents. Waveform data values, however, can only be transferred as
integers (8- or 16-bits). Suffixes are optional (but acceptable only

when specifically mentioned).

Example:

The following commands are all legal ways of setting the vertical
gain

of CHANNEL i to I00 mV/div:

CHANNEL 1VOLT/DIV .I
CHANNEL 1VOLT/DIV,IO0 MVOLT

CIVD=IOOE-03 VOLT
CIVD I00 MV

The expression <i00 MV> is considered as a single parameter with a

suffix; therefore no comma is allowed to separate them. The space
separating the parameter value and the suffix is optional.

7.4.4 Answers from the 9400A

As well as specifying a new parameter setting, it is also possible to

query the 9400A in order to obtain a current value. Such queries are

always indicated by a question mark.

Example:

TIME/DIV ?

instructs the 9400A to transmit a character

its current time base value.

Answers from the 9400A are sent in a message followed by

(see COMM TRAILER command) and <END>.

string representing

the TRAILER

7-5

Remote Operations

Example:

When set to I00 nsec/div, the answer to the query would be:

TD 100E-09<CR><LF><END>,

where <CR><LF> is the default TRAILER, and

<END> = another <CR>, when using RS-232-C (unless modified with

the command RS CONF).

= EOI-line ACCOMPANYING <LF>, when using GPIB.

If the 9400A generates multiple responses to a single message
containing queries, it will send a separate response for each query.

7.4.5 Flushing of the 94OOA’s Output Buffer

When the 9400A generates an answer to a query or outputs a data stream
in response to a transfer command, the host computer should read the
data. If it fails to do so, the 9400A may become blocked when trying to
output data (this does not occur with a response of less than 80

characters, since the output is buffered).

~henever the 9400A receives a new command message, upon detection of

the <END> of this message, it flushes the output buffer of all

responses due to the previous command message. If the 9400A detects a

new <END> from a new command message while still treating a previous

command message, it aborts those (previous) commands which generate

output data, but not the new commands. The 9400A assumes that the user

is not interested in the answers to previous commands since he is
sending another command message rather than reading the responses.

7.4.6 Command Synchronization with Data Acquisition

Some remote commands cannot be executed at all times, e.g. it is not
possible to read channel 1 or channel 2 while the oscilloscope is armed
and waiting for a trigger, since the memories of the two channels are
continuously being written into.

The user can avoid such situations entirely by only executing

single-shot acquisitions (TRIG MODE SINGLE) and by checking that bit
of status byte 4 (TRIGGERED bit) is set to one (indicating that

acquisition is complete) before sending the READ command.

Another way is to send the command to read channel 1 or channel 2. The

9400A automatically defers the execution of this command until a
waveform has been acquired. It is thus possible to also read waveforms
while the instrument is in the trigger modes NORM or AUTO, i.e.

practically "on-the-fly".

7-6

Remote Operations

Execution of the command is also deferred when using some other remote
control commands, in particular the command STORE channel I or

channel 2, and the special command WAlT whose sole purpose is to force

such a synchronization. (See Section 7.6.6 "Other Remote Commands".)

7.4.7 Character Strings

Strings
plotter
command). The string must

default string delimiter
COMM STRDELIM command).

Example:

The TRANSMIT command also outputs

decimal ASCII using a \nnn format.

Example:

If

characters, then <\\> is to be used.

may be displayed (see MESSAGE and KEY commands), sent to
(see the TRANSMIT command) or used as Prompt (see COMM PROMPT

be delimited by string delimiters. The

is <"> and may be changed (see the

COMM STRDELIM 47; MSG /OKAY/

Defines </> (decimal ASCII 47)
display OKAY on the screen.

TRANSMIT "\B27AB"

Can be used to transmit to the plotter the character ESC (decimal

ASCII 27) followed by <A> and <B>.

the backslash character <\> is to be transmitted along with other

as the string delimiter and will

characters that are specified in

Example:

Note:

"\nnn" or "\\" represent only one character of the ASCII string count.

7.4.8 Prompt

The 9400A may generate a PROMPT (see COMM-PROMPT command) when
decodes the <END> message in a command message. This PROMPT will be put

into a message as is done with all other 9400A responses (see Section

7.6.7 7)).

TRANSMIT "AI\\A2"

Instructs the 9400A to transmit the string AI\A2 to the plotter.

Remote Operations

7-7

7.4.9 Errors and Adapted Values

When it treats a command, the 9400A checks its validity. The list of
errors is presented in Section 7.6.8 (ERROR status byte).

In general:

A SYNTAX ERROR is produced when the structure of a command is

­wrong, or if a command, a key-word parameter or a suffix is not

recognized.

- A SEMANTIC ERROR is produced when the
wrong combination of parameters or if

not valid.

- An ENVIRONMENT ERROR is produced when the command, although it

is valid, cannot be accepted, the 9400A not being in the state
to do so.

When an error is detected, the corresponding code is loaded into status
byte 6, and the bit # 5 of status byte 1 is set.

Some commands cause bit 0 of status byte i (VALUE ADAPTED bit) to

set when the 9400A detects a numerical value or a parameter out of
range. The value is always modified to the closest legal value.

7.5 Data Block Transfers

Data (9400A setup values, waveform values, waveform descriptor) are

transferred between the 9400A and the Host Computer (see the READ or

SETUP commands, Section 7.6.5) or between the Host and the 9400A (see
WRITE

never
separate. This section explains only the overall block structure. For

the interpretation of the data, see Section 7.10.

or SETUP commands) in one or several blocks. Data blocks are

contained within a read or write command, but are always

command is composed of a
a numerical parameter is

Examples:

Reading a waveform from channel i of the 9400A:

- Host sends the command READ,CHANNEL 1.DATA<END> to 9400A.

- 9400A responds with one (or several) data

formats described below, and terminates
<END>.

blocks in one of the

with <TRAILER> and

Remote Operations

7-8

Thus, the overall command sequence and data structure is the same

as for queries.

Sending a new setup block to the 9400A:

- Host sends the command SETUP<END> to 9400A.

- Host sends the
composed of a

<END>.

Here, the setup data cannot be directly appended to the setup
command, but must be separated by <END>.

Several block formats are available for read and write; they are

distinguished from each other by the preamble. The command COMM FORMAT
selects the format.

Format A: GPIB only, binary format, no checksum.

Preamble:

Data:

Postscript: None.

Format L: GPIB or RS-232-C, ASCII format.

Preamble: #L<count>, where <count> is

#Abb where bb is the number of data values that will be
sent (2 binary bytes).

One binary byte for each 8-bit value, two binary bytes
for each 16-bit value.

that will be sent.

data blocks to the 9400A. Each data block is

preamble, the data, an optional postscript and

the number of data values

Data: <data>, where <data> are data values in ASCII.

Postscript: None.

<count> and <data> are in the same format but do not necessarily have

the same number of characters. However, <count> is always treated as a
WORD (16 bits), whereas <data> may be chosen as a BYTE (8 bits) or
WORD. The choice of formats (see COMM FORMAT command) is the following:

HEX:

UNSIGNED FIXED:

UNSIGNED SHORT:

BYTE (8 bits value) WORD

xx (2 hex digits) xxxx

nnn (3 decimal digits)

,n (I to 3 decimal digits) ,nnnnn (I to 5 decimal

7-9

nnnnn

(16 bits value)

(4 hex digits)

(5 decimal digits)

digits)

Remote Operations

The HEX and UNSIGNED FIXED are fixed size formats, whereas
UNSIGNED SHORT is a variable size format. Therefore, it requires commas

to separate the values.

Examples:

HEX format: #LOOOA0102030405060708090A
UNSIGNED FIXED: #L...I0..I..2..3..4..5..6..7..8..9.10

UNSIGNED SHORT: #L,10,1,2,3,4,5,6,7,8,9,10

Note:
The conversion type and the size must be fixed before reading AND
writing data.

Data transfers via RS-232-C can only be made in ASCII formats.

If the host computer allows only small amounts of data to be sent or
read, the transfer may be partitioned into several blocks of the
selected format. The maximum length of each block is determined by the
COMM BLOCKSIZE command. The length includes all bytes or characters of

the -block as well as characters which may compose the <TRAILER> and

<END>.

Each dot repre­sents a space
character

The transfer will be structured as follows:

st

I

Block -- <TRAILER><END> -- 2

.... -- Last Block -- <TRAILER><END> -- END block -- <TRAILER><END>

Where the END block is:

When reading data from the 9400A, the exact form of
determined by the command COMM TRAILER. <END> is:

<END> = <CR> when using RS-232-C (unless modified with the command

RSCONF).

= EOI ACCOMPANYING the last character of TRAILER, when in GPIB.

If the 9400A receives another command message, terminated with <END>,
while sending data, the transfer is aborted and status byte 6 (ERROR)
is set to the value i.

Data may be lost if the readout sequence is interrupted with a Serial
Poll or by the untalk command.

nd

Block -- <TRAILER><END> -- ....

the TRAILER is

#I

7-10

Remote Operations

Thus, the overall command sequence and data structure is the same
as for queries.

Sending a new setup block to the 9400A:

- Host sends the command SETUP<END> to 9400A.

- Host sends the
composed of a
<END>.

Here, the setup data cannot be directly appended to the setup
command, but must be separated by <END>.

Several block formats are available for read and write; they are
distinguished from each other by the preamble. The command COMM FORMAT

selects the format.

Format A: GPIB only, binary format, no checksum.

Preamble:

Data: One binary byte for each 8-bit value, two binary bytes

Postscript: None.

Format L: GPIB or RS-232-C, ASCII format.

Preamble:

#Abb where bb is the number of data values that will be
sent (2 binary bytes).

for each 16-bit value.

#L<count>, where <count> is the number of data values

that will be sent.

data blocks to the 9400A. Each data block is

preamble, the data, an optional postscript and

Data: <data>, where <data> are data values in ASCII.

Postscript: None.

<count> and <data> are in the same format but do not necessarily have

the same number of characters. However, <count> is always treated as a
WORD (16 bits), whereas <data> may be chosen as a BYTE (8 bits) or
WORD. The choice of formats (see COMM FORMAT command) is the following:

WORD

(16 bits value)

(4 hex digits)

(5 decimal digits)

digits)

Remote Operations

HEX:

UNSIGNED FIXED:

UNSIGNED SHORT:

BYTE (8 bits value)

xx (2 hex digits) xxxx

nnn (3 decimal digits) nnnnn

,n (I to 3 decimal digits) ,nnnnn (I to 5 decimal

7-9

The HEX and UNSIGNED FIXED are fixed size formats, whereas
UNSIGNED SHORT is a variable size format. Therefore, it requires commas

to separate the values.

Examples:

HEX format: #L000A0102030405060708090A
UNSIGNED FIXED: #L...I0..I..2..3..4..5..6..7..8..9.10

UNSIGNED SHORT: #L,I0,I,293,4,5,6,7,8,9,10

Note:
The conversion type and the size must be fixed before reading
writing data.
Data transfers via RS-232-C can only be made in ASCII formats.

If the host computer allows only small amounts of data to be sent or

read, the transfer may be partitioned into several blocks of the
selected format. The maximum length of each block is determined by the
COMM BLOCKSIZE command. The length includes all bytes or characters of

the -block as well as characters which may compose the <TRAILER> and
<END>.

Each dot repre­sents a space
character

AND

The transfer will be structured as follows:

st

i

Block -- <TRAILER><END> -- 2

.... -- Last Block -- <TRAILER><END> -- END block -- <TRAILER><END>

Where the END block is:

When reading data from the 9400A, the exact form of
determined by the command COMM TRAILER. <END> is:

<END> = <CR> when using RS-232-C (unless modified with the command

RS_CONF).

= EOI ACCOMPANYING the last character of TRAILER, when in GPIB.

If the 9400A receives another command message, terminated with <END>,

while sending data, the transfer is aborted and status byte 6 (ERROR)

is set to the value I.

Data may be lost if the readout sequence is interrupted with a Serial
Poll or by the untalk command.

nd

Block -- <TRAILER><END> -- ....

the TRAILER is

#I

7-10

Remote Operations

7.6

7.6.1 Notation

Commands

In this section the following notation is used to explain the commands.
However, these symbols must not be sent to the 9400A as part of a

command.

[ to ]

< >

indicates commands which can be executed in REMOTE only.

Queries (terminated with a <?>) are always allowed.

** indicates commands which can only be executed in REMOTE when

the display intensity controls have also been set to REMOTE.

Example:

TIME/DIV (TD) , < ?

"TIME/DIV" is the long format of the
time base.

denotes the range of a numerical value.

denotes the choice of parameters.
The options are listed vertically.

denotes the abridged format of a keyword.

)

denotes a separator which may be <,> or a space or <=>.
The last two are only acceptable between the header and

the first parameter~ not between parameters.

< [ 2 NS to I00 S ] >

command for controlling the

"TD" is the short form equivalent of
be used at all times.

The comma is the separator between the header and the first
parameter. It may be replaced by a space or by an equal sign <=>,
or by any combination of these. Note that subsequent parameters
MUST be separated from each other by commas only.

The parentheses < > show that the choice of the first (and only)
parameter is either <?> or a time base value in the range of
2 nsec to I00 sec.

The asterisk <*> indicates that this command can only be executed
when the 9400A is in the REMOTE state. However the query

"TIME/DIV 7,,

¯ , can be executed at any time.

7-11

"TIME/DIV". Either form may

Remote Operations

7.6.2 Acquisition Parameter Commands

i) TIME/DIV (TD)

Other available suffixes are: US (Bsec, microseconds) and MS (msec,
milliseconds).

The 9400A sets the VALUE ADAPTED bit:

- if an out-of-range value is given.

- if a value outside the incremental steps of i, 2, 5 is given.

Examples:

TD = ?

TD 20 US
TIME/DIV 12 MS

2) INTERLEAVED (IL) , <? >

Enables or disables Interleaved Sampling.

, <? >

< [ 2 NS to I00 S ] >

Instructs the 9400A to send the current time base
value.
Sets the 9400A to 20 Bsec per division.
Sets the 9400A to I0 msec; since the value is
modified from 12 msec to I0 msec, the VALUE ADAPTED

bit in status byte 1 is set.

< ON > *
< OFF > *

The 9400A sets the ENVIRONMENT ERROR:

- if ON command is sent while the time base is greater than 2 US.

- if OFF command is sent while the time base is less than 50 NS.

3) TRIG DELAY (TRD) , < ?
< [ 0.00 % to i00.00 % ] >

<

[ -0.04 NS to -I000000 S ] >

Positive format:

Negative format:

Valid

steps of 1/50 of a division. If the TIME BASE is changed, the

delay remains the same or may change just slightly due to rounding,

provided that it does not exceed I0000 divisions.

Note:
In the case of post-trigger delay, the remote value is negative

while the corresponding value displayed on the screen is positive.

delay v~ues correspond to 0 to i0000 time base divisions in

pre-trigger.
post-trigger delay.

7-12

Remote Operations

The 9400A sets the VALUE ADAPTED bit:

- if a positive out-of-range value is given.

- if a negative value corresponding to more than i0000 divisions is

given.

4) TRIG LEVEL (TRL) , < ?

, < [ -5.00 DIV to 5.00 DIV ] >

when the oscilloscope is set to one of the

internal trigger sources (CHANNEL_I or
CHANNEL_2).

, < [ -2.00 V to 2.00 V ] >

when the oscilloscope is set to in the EXT

trigger source.

, < [ -20.0 V to 20.0 V ] >

when the oscilloscope is set to the EXT/10

trigger source.

When the oscilloscope is set to LINE trigger source, this command
has no meaning and no error will be reported. In the case of POS_NEG

triggering, only a positive value is meaningful.

The 9400A sets the VALUE ADAPTED bit:

- if an out-of-range value is given.

The 9400A sets the ENVIRONMENT ERROR:

- if the DIV suffix is sent instead of V or if the V suffix is sent
instead of DIV.

5) TRIG COUPLING (TRC) , < ?

< AC > *
< DC > *
< LF REJ (LF)
< HF-REJ (HF)

6) TRIG MODE (TRM)

The 9400A sets the ENVIRONMENT ERROR:

- if SEQNCE is sent while the 9400A is in Interleaved Sampling.

7) TRIG SOURCE (TRS) , < ?

, < ?

< SEQNCE (SE) > *
< AUTO (AU)

< NORM (NO)

< SINGLE (Sl)

< CHANNEL i (CI)
< CHANNEL-2 (C2)
< LINE (eI)
< EXT (EX)
< EXT/IO (E/IO)

>

>

> *
> *
> *

> *

> *
> *

*
*

*
*

7-13

Remote Operations

8) TRIG SLOPE (TRP)

, < ?

< POS (P0)
< NEG (NE)
< POS NEG (PN)

>
>

>

*
*

*

9) SEGMENTS (SEG)

Indicates or selects the number of segments for waveforms acquired

in SEONCE mode.

CHANNEL 1 VOLT/DIV (CIVD)

i0)

CHANNEL 2 VOLT/DIV (C2VD)

The range of the Volts/div setting is limited to 2.5 Volts per
division in the case of 50 Q coupling.

Note that this value corresponds to the 9400A input gain. It does
not take probe attenuation factors into account.

The 9400A sets the VALUE ADAPTED bit:

- if an out-of-range value is given.

Examples:

, <?

<8

< 15
< 31 > *

< 62 > *
< 125 > *
< 250

, <? >

< [ 5.000 MV to 12.500 V ] >

>

>

>

>

*

*

*

CHANNEL_2_VOLT/DIV,500 MV
CIVD=.5

C2VD 120 MV

ii) CHANNEL 1 ATTENUATION (CIAT)

CHANNEL 2 ATTENUATION (C2AT)

Indicates or selects the attenuation factor of the probe.

12) CHANNEL 1 OFFSET (CIOF)
CHANNEL 2 OFFSET (C20F)

The 9400A sets the VALUE ADAPTED bit:

- if an out-of-range value is given.

Sets channel 2 to 500 mV/div
Sets channel 1 to 500 mV/div

Sets channel 2 to 120 mV/div by
choosing I00 mV/div fixed gain and

setting the variable gain to the

required value.

, <? >

< i > *
< I0
< i00 > *
< I000 > *

, <? >

< [ -8.00 DIV to 8.00 DIV ] >

7-14

>

Remote Operations

*

13) CHANNEL I COUPLING (CICP)
CHANNEL 2 COUPLING (C2CP)

, <? >

< AC 1 MOHM (AIM)
< DC 1 MOHM (DIM)

< GND

< DC 50 OHM (D50)

> *

> *
>
> *

*

14) BANDWIDTH (BW)

15) STOP

Stops the acquisition of a signal. This command may be used to
return the 9400A from the "armed" state to the "triggered" state,

when the trigger is absent. It generates records similar to those

produced in the AUTO trigger mode.

It is also useful to stop a SEQNCE acquisition when the number of

triggers available is insufficient to fill all sweeps. Upon receipt
of the STOP command, the 9400A displays the artificially completed
sweeps as GND lines.

7.6.3 Display Commands

i) DUAL GRID (DG) , <

- < ON > *

Examples:

, <? >

< ON > *
< OFF > *

< OFF > *

DUAL GRID ON

DG OFF

TRACE CHANNEL I (TRCI)

2)
TRACE-CHANNEL-2 (TRC2)

TRACE-EXPAND A (TREA)
TRACE-EXPAND-B (TREB)
TRACE-MEMORY-C (TRMC)

TRACE-MEMORY-D (TRMD)
TRACE-FUNCTION E (TREE)
TRACE-FUNCTION-E (TREE)

The 9400A sets the ENVIRONMENT ERROR:

- i~h 4 traces are already ON, and a command is received

5

trace ON.

, <?

7-15

Instructs the 9400A to display dual
grids.
Instructs the 9400A to display a

single grid of 8 x i0 squares.

>
< ON > *
< OFF > *

Remote Operations

to turn a

Examples:

TRCI ?

TRMC = OFF

3) SELECT (SEL)

Instructs the 9400A to send a message,

indicating whether the display of channel I is

on or off.
Instructs the 9400A to turn the display of

memory C off.

, <? >

< EXPAND A (EA)
< EXPAND-B (EB)

< MEMORY-C (MC)
< MEMORY-D (MD)

< FUNCTION E (FE)
< FUNCTION-F (FF)

> *
> *

> *
> *

> *
>

ii
ii
ii

ii
II

*

Selects a display trace, similar to the front panel control.

Thereafter, the commands VERT GAIN, VERT POSITION, TIME_MAGNIFIER,

HOR POSITION and REDEFINE will-be applied to the SELECTed trace.

The 9400A sets the ENVIRONMENT ERROR:

- if the SELECTed trace is OFF.

4) VERT GAIN (VG) , < ?

-

VERT GAIN is applied to the SELECTed trace. This command instructs

the 9400A to modify the display gain (not the acquisition gain) by
factor of up to 2.5.

< [ 1.000 to 2.500 ] >

>

II

II

II
I

II
II

II

7-16

Remote Operations

Adj us tment

Manually appears in the window* on value in the window*

Reduce Signal Size

Turn the Vert. Gain knob Turn the Vert. Gain knob

anti-clockwise. clockwise.

Notice that a ">" symbol Notice that the volts

9400A screen. changes, e.g. ".5 V"

Increase Signal Size

changes to "> .2 V"

Read the exact V/div in

the memory STATUS menu. the memory STATUS menu.

Enter the command "VG ?"

Query

The response is a value between i and 2.5.

Exact V/div = response x value indicated in the

select window on 9400A screen.

I

Remote

Control value between I and 2.5

* assumes that cursors are not being used

Enter "VG" followed by a

to attenuate the signal

up to 2.5 times.

I

Read the exact V/div in

Not possible

The 9400A sets the VALUE ADAPTED bit:

- if an out-of-range value is given.

The 9400A sets the ENVIRONMENT ERROR:

- if the SELECTed trace is OFF.

5) VERT POSITION (VP) ,

VERT POSITION is applied to the SELECTed trace. This command

instructs the 9400A to modify the display position (not the

acquisition offset) of the selected trace by up to ± 16 divisions,

relative to the original position at acquisition.

<? >
< [ -16.00 DIV to 16.00 DIV ] >

Remote Operations

7-17

The 9400A sets the VALUE ADAPTED bit:

- if an out-of-range value is given.

The 9400A sets the ENVIRONMENT ERROR:

- If the SELECTed trace is OFF.

6) TIME MAGNIFIER (TM) , < ?

< [ 0 to6 ] >

TIME MAGNIFIER is applied to the SELECTed trace. It may only be

applTed to traces EXPAND A or EXPAND B.
The value 0 corresponds to no expansion. Each increment of I
corresponds to the next lower time base value (relative to the
original trace). The value 6 therefore allows an expansion by

factor of I00.

The 9400A sets the VALUE ADAPTED bit:

- if an out-of-range positive value
generate a semantic error.

The 9400A sets the ENVIRONMENT ERROR:

- if the SELECTed trace is OFF.

- if the SELECTed trace is neither EXPAND A nor EXPAND B.

7) HOR POSITION (HP) , <

, < [ 0.0000 DIV to i0.0000 DIV ] >

when the source trace corresponds to a single
waveform (acquired in single shot or with

INTERLEAVED ON).

, < [ 1 to max ] >

when the source trace corresponds to multiple
waveforms (acquired in SEQNCE).
The parameter indicates the number of the

sequence to be displayed. "max" depends on the
selected number of segments (see SEGMENTS).

HOR POSITION will be applied to the SELECTed trace. It may only be
applied to traces EXPAND A or EXPAND B. The parameter in the range
0 to I0 divisions corresponds to The CENTER of the intensified
region on the original trace. The smallest possible step is

0.0004 div.

is given. Negative values

>

The 9400A sets the VALUE ADAPTED bit:

- if an out-of-range value is given (Interleaved Sampling or Single
Shot).

- if a positive out-of-range value is given (SEQNCE). Negative
zero values generate a semantic error.

Remote Operations

7-18

The 9400A sets the ENVIRONMENT ERROR:

- if the SELECTed trace is OFF.

- if the SELECTed trace is neither EXPAND A nor EXPAND B.

8) REDEFINE (RDF)

Redefines the source of the SELECTed trace to
CHANNEL 2, MEMORY_C,

EXPAND A or EXPAND B.

The 9400A sets the ENVIRONMENT ERROR:

- if the SELECTed trace is OFF.

- if the SELECTed trace is neither EXPAND A nor EXPAND B.

9) MESSAGE (MSG)

The string may be up to 43 characters in length. The message is

displayed in
Section 4.6).

Example:

MESSAGE "Apply probe to Jll.5, then press READY"

, < ?

< CHANNEL I (Cl)
< CHANNEL-2 (C2) > *
< MEMORY C (MC) > *
< MEMORY-D (MD)

or MEMORY_D. The SELECTed

, <String to be displayed>

the Message Field above the graticule (see

>

>

> *

be CHANNEL i,

trace must be

*

Instructs the 9400A to display the message between the
string delimiters " on the line above the graticule.

The push button READY does not exist on the 9400A, but any

of 9 soft keys may be defined as such with the command KEY.

i0) KEY , < [I to 9] > , <String to be displayed>

The string is displayed in the Menu Field (see Section 4.1) next

the soft key selected with the first parameter. The string may be up
to Ii characters in length.

Examples:

KEY 3,!READY!

Instructs the 9400A to display the message "READY" next to

the third (from the top) soft key on the left hand side
the graticule. This command is only accepted if the string

delimiter has been changed from the default value <"> to

<!> with the command COMM STRDELIM=33. The default value
<"> = 34 (see Section 7.6.7).

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Remote Operations

KEY l, "Restart"

Instructs the 9400A to display the message "Restart" next
to the first soft key. Here, the default string delimiter
is used.

11) SCREEN (SCR)

, <? >

< REMOTE (RM) *
< LOCAL (LC) *

or

SCREEN (SCR) , < ON **

< OFF > **

or

SCREEN (SCR) , < INTENSITY (INT) > , [0 to

< GRID INTENSITY (GI)>

"?" allows the user to know the status of the screen.

"REMOTE" and "LOCAL" select the control mode of the screen.

When the 9400A is set to REMOTE, the screen remains under LOCAL

control allowing the operator to adjust the display intensity. The

screen itself must be put into the REMOTE state using the command

SCREEN (SCR) , <ON> before the commands marked with "**" are valid.

"ON" and "OFF" turn the screen ON an OFF respectively.

When the 9400A is being used to capture transients automatically
without a user looking at the display, the display may be turned
off. This improves the response time of the instrument since display
generation, which may take up to I00 msec, is suppressed.

**

**

"INTENS" and "GRID INT" set the display intensity.

The 9400A sets the VALUE ADAPTED bit:

- if a value greater than 170 is given.

7.6.4 Plotter Commands

i) PLOTTER (PT)

or

PLOTTER (PT)

, <? >

, <name> , <port> , <speed> , <pens>

Remote Operations

7-20

<name> = < GRAPHTEC (GR) >

< HEWLETT PACKARD (HP) >
<

PHILIPS (PH)

<

TEKTRONIX (TEK)

>
>

<port> = < RS232 (RS)

< GPIB (SP)

<speed> < NORMAL SPEED (NS)

< LOW SPEED (LS)

<pens> = [ 1 to 9 ]

Configures the 9400A for a predefined plotter.

Examples:

PLOTTER HP,RS,NS,2

Configures the 9400A for a Hewlett-Packard plotter,
connected to the RS-232-C plotter port, running at normal

speed, with 2 pens. This is how the 9400A must be
configured for the HP7470 and HP7475 or compatible
plotters.

PT,GR,GP,LS,4

Configures the 9400A for a Graphtec FP5301 or compatible
plotter, connected through GPIB, running at low speed (for

plotting on transparencies), with 4 pens.

2) PLOT SIZE (PS) , <? >

< A5 > *
< A4 > *
< A3 > *

Configures the 9400A to plot onto a predefined paper size.

AS=
A4=
A3 =

or

148 mm by 210 mm, compatible with U.S. 5 1/2" by 8 1/2"
210 mm by 297 mm, compatible with U.S. 8 1/2" by II"
297 mm by 420 mm, compatible with U.S. ii" by 17"

PLOT SIZE (PS) , NON STANDARD (NSTD) , <grid> , <x> ,

Configures the 9400A to plot onto a non-standard paper size.

<grid> = [ 00.0 MM to 99.9 MM ]

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Remote Operations

<x> = [ 0 MM to 999 MM ]

<y> [ 0 MM to 999 MM ]

<grid> is the size (length of a side) of the standard square
within the 8 times I0 squares grid.

<x>,<y> are the positions of the lower left hand corner of the

graticule with respect to the origin of the plotter.

The 9400A sets the VALUE ADAPTED bit:

- if an out-of-range positive value
generate a semantic error.

3) SCREEN DUMP (SD)

Instructs the 9400A to dump the screen display onto the plotter.

4) TRANSMIT (TX) , <String to be transmitted to the plotter>

Instructs the 9400A to transmit a character string to the plotter.

The string may be up to 43 characters in length and may include

commands such as "paper advance" or "print string". This enables the
user to add comments to a plot, or generate multiple plots by remote

control.

The 9400A sets the ENVIRONMENT ERROR:

- if the 9400A is controlled through GPIB and if the plotter access
port is the GPIB port.

7.6.5 Transfer Comm~,ds

i) STORE (STO) , [ 1 to

is given. Negative values

*

instructs the 9400A to store the current front panel configuration
in one of 7 non-volatile storage areas for later recall.

or

STORE (STO)

, < CHANNEL 1 (CI) > , < MEMORY C (MC)

< CHANNEL-2 (C2) > < MEMORY-D (MD)

instructs the 9400A to store the waveform and the waveform

descriptor of either Channel 1 or 2 into reference memories C or D.

Notes:

If the 9400A receives a command to store Channel 1 or 2 while it is

acquiring data, the execution of the command is delayed until the

trigger has arrived.

Remote Operations

7-22

No message will be displayed on the screen when the operation is
performed.

2) RECALL (REC) , [ 1 to

instructs the 9400A to recall one of 8 front-panel configurations
stored in non-volatile memory. The value "8" corresponds to the
default setup.

3) SETUP (SU)

or

SETUP (SU) *

The first form permits the complete setup to be read in internal

data representation. Transmission format depends on the selected

forms by the COMM FORMAT command. The setup data block corresponds

to 257 binary bytes.

The second form permits setup data to be sent to the 9400A in the

same form as they were read from the 9400A. This command must be

terminated with <END>, i.e. it must be the last of a list of
commands. The data transferred to the 9400A must be contained in a
separate block (see Section 7.5).

Note:
The serial port parameters can not be transmitted. In particular, if

the transfers are by RS-232-C, modification of the serial port

parameters by this command would bring about some strange results.

The 9400A sets the VALUE ADAPTED bit:

- if a data value in the block is incorrect. The DEFAULT setup will
be used in this case.

The 9400A sets the INVALID BLOCK ERROR:

- if the received block(s) is incorrect.

4) READ (RD)

, < CHANNEL I.DESC

< CHANNEL-2.DESC
< MEMORY C.DESC
< MEMORY D.DESC

(CI.DE)
(C2.DE)
(MC.DE)
(MD.DE)

transfer the descriptor of the indicated waveform from the 9400A to
the host computer. See Section 7.7 for the format of this data

block.

or

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Remote Operations

READ (RD)

, < CHANNEL 1.DATA

< CHANNEL 2.DATA
< MEMORY C.DATA
< MEMORY-D.DATA

(CI.DA) > , <Parameter list>
(C2.DA) >
(MC.DA)
(MD.DA)

<Parameter list> = <intval> , <# values> , <addr> , <sweep #>

transfer the data values of the indicated waveform from the 9400A to
the host computer. An explanation of the optional parameter list is

given below.

or

READ (RD) , < CHANNEL 1.TIME

< CHANNEL-2.TIME
< MEMORY C.TIME
< MEMORY-D.TIME

(CI.TI)
(C2.TI)
(MC.TI)
(MD.TI)

transfer the trigger time(s) of the indicated waveform from the
9400A to the host computer. See Section 7.8 for the format of this

data block.

or

READ (RD) , < CHANNEL I.* (CI.*) > , <Parameter list>

<

CHANNEL-2.* (C2.*)

< MEMORY C.* (MC.*)
< MEMORY-D.* (MD.*)

transfer ALL visible data of the indicated waveform from the 9400A

to the host computer. Data are transferred in the order descriptor,

data, time(s).

<Parameter list> = <intval> , <# values> , <addr> , <sweep #>

<intval> = [ 1 to 16000 ]

Interval between data points to be
read, for example:

I = read all points
4 = leave out 3 of 4 data values

<# values>= [ 0 to 32000 ]

<addr> = [ -32000 to 32000 ]

Number of data values to read

Address of first data

relative to the left hand

the screen

<sweep #> = [ 0 to 250 ] Sweep number in SEQNCE

numbered from
1 to max. # sweeps
0 = read all sweeps

Remote Operations

7-24

point

side of

waveforms,