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I REMOTE CONTROL MANUAL
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II MODELS9410/14/20/24/30/50
DUAL- AND QUAD-CHANNEL
DIGITAL OSCILLOSCOPES
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May 1992

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LeCroy
Corporate Headquarters
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700 Chestnut Ridge Road
Chestnut Ridge, NY 10977-6499
Tel: (914) 425-2000, TWX: 710-577-2832
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European Headquarters
2, rue Pr~-de-la-Fontaine
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P.O. Box 341
1217 Meyrin 1/Geneva, Switzerland
Tel.: (022) 719 21 11, Telex: 419 058 i
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Copyright~ May 1992, LeCroy. All rights reserved, information in this
publication supersedesall earlier versions. Specifications subject to change. g
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I TABLE OF CONTENTS
1
General Information
Initial Inspection 1
Warranty 1
Product Assistance 1
Maintenance Agreements 1
Document Discrepancies 2
Service Procedure 2
Return Procedure 2

2 About Remote Control
GPIB Implementation Standard
Program Messages
Commands and Queries
Local and Remote State
Program Message Form
Command/Query Form
Response Message Form

3 GPIB Operation
GPIB Structure 11
Interface Capabilities 11
Addressing 12
GPIB Signals 12
IEEE 488.1 Standard Messages 13
Programming GPIB Transfers 15
Programming Service Requests 19
Instrument Polls 21
Driving a Hard-copy Device 25

4 RS-232-C Operation
Introduction 29
RS-232-C Pin Assignments 29
RS-232-C Configuration 30
Commands Simulating GPIB Commands 33
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Table of Contents
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System Commands
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Organization
Command Summary 35
Command Execution 37 |
Command Notation 37

6 WaveformStructure
Introduction 179
Logical Data Blocks of a Waveform 179
Inspect? Command 180
Waveform? Command 182
Waveform Command 187
More Control of Waveform Queries 188
High-speed Waveform Transfer 188

Status Registers
Overview of Status and Service Request Reporting 191
Status Byte Register (STB) 193
Standard Event Status Register (ESR) 194
Standard Event Status Enable Register (ESE) 195
Service Request Enable Register (SRE) 195
Parallel Poll Enable Register (PRE) 195
Internal State Change Status Register (INR) 195
Internal State Change Enable Register (INE) 196
CommandError Status Register (CMR) 196
Device Dependent Error Status Register (DDR) 196
Execution Error Status Register (EXR) 196
User Request Status Register (URR) 196
Table of Contents


Appendix A
Example 1: Use of the Interactive
GPIB Program 'IBIC' 199
Example 2: GPIB Program for IBM PC
(High-level Function Calls) 200
Example 3: GPIB Program for IBM PC
(Low-level Function Calls) 202

Appendix B
The Waveform Template 205
GENERAL INFORMATION
1
INITIAL INSPECTION It is recommendedthat the shipment be thoroughly inspected im-
mediately 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 Customer Service Depart-
ment or local field office immediately.

WARRANTY LeCroywarrants its oscilloscope products to operate within specifi-
cations under normal use for a period of two years from the date of
shipment. Spares, replacement parts and repairs are warranted for
90 days. The instrument's firmware is thoroughly tested and
thought to be functional, but is supplied "as is" with no warranty of
any kind covering detailed performance. Products not manufac-
tured by LeCroy are covered solely by the warranty of the original
equipment manufacturer.
In exercising this warranty, LeCroywill repair or, at its option,
replace any product returned to the Customer Service Department
or an authorized service facility within the warranty period, pro-
vided that the warrantor's examination discloses that the product
is defective due to workmanshipor materials and that the defect
has not been caused by misuse, neglect, accident or abnormal con-
ditions or operation.
The purchaser is responsible for transportation and insurance
charges for 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 im-
plied, including but not limited to any implied warranty of
merchantability, fitness, or adequacyfor any particular purpose or
use. LeCroyshall not be liable for any special, incidental, or con-
sequential damages, whether in contract or otherwise.

PRODUCT ASSISTANCE Answersto 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., tel. (914)578-6061, and 2, rue
Pr6-de-la-Fontaine, 1217 Meyrin 1, Geneva, Switzerland, tel.
(41)22/719 21 11, or your local field engineering office.

MAINTENANCE LeCroy offers a selection of customer support services. Mainte-
AGREEMENTS nance agreements provide extended warranty and allow the
customer to budget maintenance costs after the initial two year
warranty has expired. Other services such as installation, training,
enhancements and on-site repair are available through specific
Supplemental Support Agreements.
General Information


DOCUMENTATION LeCroy is committed to providing state-of-the-art instrumenta-
DISCREPANCIES tion 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 cir-
cuitry. In a similar way the firmware may undergo revision when
the instrument is serviced. Should this be the case, manual up-
dates will be made available as necessary.

SERVICE PROCEDURE Products requiring maintenance should be returned to the Cus-
tomer Service Department or authorized service facility. LeCroy
will repair or replace any product under warranty at no charge.
The purchaser is only responsible for transportation charges.
For all LeCroy products in need of repair after the warranty pe-
riod, the customer must provide a Purchase Order Numberbefore
repairs can be initiated. The customer will be billed for parts and
labor for the repair, as well as for shipping.

RETURN PROCEDURE To determine your nearest authorized service facility, contact the
Customer Service Department 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 re-
turned to the factory, a Return Authorization Number (RAN).
The RAN may be obtained by contacting the Customer Service
Department in New York, tel. (914)578-6061, in Geneva, tel.
(41)22/719 21 11, 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 rec-
ommended. Wherever possible, the original shipping carton
should be used. If a substitute carton is used, it should be rigid and
be packed such that the product is surrounded with a minimum of
four inches of excelsior or similar shock-absorbing material. In
addressing the shipment, it is important that the Return Authoriza-
tion Numberbe displayed on the outside of the container to ensure
its prompt routing to the proper department within LeCroy.
ABOUT REMOTE CONTROL
2
Twomodesof operation are available in the oscilloscope. The in-
strument may be operated either manually, by using the
front-panel controls, or remotely by means of an external control-
ler (which is usually a computer, but may be a simple terminal).
This Remote Control Manual describes how to control the oscillo-
scope in the remote mode. For explanations on how to manually
set front-panel controls, refer to the Operator's Manual.
The oscilloscope is remotely controlled via either the GPIB(Gen-
eral Purpose Interface Bus) or the RS-232-C communication
ports. Wheneverthe rear-panel GPIBaddress switches are set be-
tween 0 and 30, control is via GPIB; when they are at 31 or above,
control is via RS-232-C. The instrument can be fully controlled in
remote mode. The only actions which cannot be performed re-
motely are switching on the instrument or setting the remote
address.
This section introduces the basic remote control concepts which
are commonto both RS-232-C and GPIB. It also presents a brief
description of remote control messages.
Sections 3 and 4 explain how to send program messages over the
GPIBor the RS-232-C interfaces, respectively. Section 5 alpha-
betically lists all the remote control commands.Section 6 is a
detailed description and tutorial of the transfer and format of
waveforms, whereas Section 7 explains the use of status bytes for
error reporting. Appendix A shows some complete programming
examples. Appendix B contains a printout of a waveform tem-
plate.

GPIB IMPLEMENTATION
STANDARD The remote commands conform to the GPIB IEEE 488.2 stan-
dard 1. This standard may be seen as an extension of the
IEEE 488.1 standard which dealt mainly with electrical and me-
chanical issues. The IEEE 488.2 recommendations have also
been adopted for RS-232-C communications whenever applica-
ble.

PROGRAM MESSAGES To remotely control the oscilloscope the controller must send pro-
gram messages which conform to precise format structures. The
instrument will execute all program messages which are in the cor-
rect form and ignore those where errors are detected.



1. ANSI/IEEE Std. 488.2-1987, "IEEEStandard Codes, Formats, Protocols, and Common Commands", The
Institute of Electrical and Electronics EngineersInc., 345 East 47th Street, NewYork, NY10017, USA.
About Remote Control


Warningor error messages are normally not reported by the instru-
ment, unless the controller explicitly examinesthe relevant status
register, or if the status enable registers have been set in such a way
that the controller can be interrupted when an error occurs. The
status registers are explained in Section 7.
During the development of the control program it is possible to
observe all remote control transactions, including error messages,
on an external monitor connected to the RS-232-C port. Refer to
the command "COMM_HELP" further details.
for

COMMANDS
AND QUERIES Program messages consist of one or several commands queries.
or
A commanddirects the instrument to change its state, e.g. to
change its time base or vertical sensitivity. A query asks the instru-
ment about its state. Very often, the same mnemonic used for a
is
command and a query, the query being identified by a after
the last character.
For example, to change the time base to 2 msec/div, the controller
should send the following commandto the instrument
TIME DIV 2 MS
To ask the instrument about its time base, this query should be
sent
TIME DIV?
A query causes the instrument to send a response message. The
control program should read this message with a "read" instruc-
tion to the GPIB or RS-232-C interface of the controller. The
response message to the query above might be
TIME m DIV 10 NS
The portion of the query preceding the question mark is repeated
as part of the response message. If desired, this text may be sup-
pressed with the command "COMM_HEADER".
Depending on the state of the instrument and the computation to
be done, the controller may have to wait up to several seconds for
a response. Command interpretation does not have priority over
other oscilloscope activities. It is therefore judicious to set the con-
troller IO timeout conditions to 3 or more seconds. In addition, it
must be rememberedthat an incorrect query message will not gen-
erate a response message.




4
About Remote Control 2
LOCAL AND REMOTE
STATE As a rule, remote commandsare only executed by the instrument
when it is in the REMOTE state, whereas queries are always ex-
ecuted. A few commands which don't affect the state of the front
panel are also executed in LOCAL (refer to the beginning of Sec-
tion 5 for a list of these commands). Whenthe instrument is in
REMOTE, front-panel controls are disabled, except the left-
all
hand menu buttons, the intensity controls (which can be disabled
with the command "INTENSITY") and the LOCAL button
(which can be disabled by setting the instrument to LOCAL
LOCKOUT). an explanation on how to set the instrument to
For
LOCAL, REMOTE LOCALLOCKOUT,
or refer to Section 3 for
GPIB and to Section 4 for RS-232-C.

PROGRAM MESSAGE
FORM An instrument is remotely controlled with program messages
which consist of one or several commands queries, separated by
or
semicolons <;> and ended by a terminator:
; ......... ;
Upper and/or lower case characters can be used for program mes-
sages.
The instrument does not decode an incoming program message
before a terminator has been received (exception: if the program
messageis longer than the 256 byte input buffer of the instrument,
the oscilloscope starts analyzing the message when the buffer is
full). The commands queries are executed in the order in which
or
they are transmitted.
In GPIBmode, the following are valid terminators:
New-line character (i.e. the ASCII new-line
character, whose decimal value is 10).
New-line character with a simultaneous
signal.
signal together with the last character of
the program message.
Note: The signal is a dedicated GPIBinterface line which
can be set with a special call to the GPIBinterface driver. Refer to
the GPIB interface manufacturer's manual and support pro-
grams.
The terminator is always used in response messages
sent by the instrument to the controller.
In RS-232-C, the terminator may be defined by the user with the
command "COMM_RS232". The default value is , i.e. the
ASCII carriage return character, the decimal value of which is 13.
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About Remote Control
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Examples GRID DUAL This program message consists of a
single command which instructs the
instrument to display a dual grid.
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The terminator is not shownsince it
is usually automatically added by
the interface driver routine which |
writes to the GPIB (or RS-232).
BWL ON; DISPLAY OFF; DATE?
This program message consists of
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two commands, followed by a
query. They instruct the instrument
to turn on the bandwidth limit, turn
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off the display, and then ask for the
current date. Again, the terminator
is not shown. I
COMMAND/QUERY
FORM The general form of a command a query consists of a command
or
header
which is optionally followed by one or several
1
parameters separated by commas:
[?] ..... I
The notation [?] shows that the question mark is optional (turning
the command into a query). The detailed listing of all commands
in Section 5 indicates which commands may also be queries. |
There is a space between the header and the first parameter.
There are commas between parameters.

Example DATE 15,OCT,1989,13,21,16
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This command instructs the oscillo-
scope to set its date and time to 15
OCT 1989, 13:21:16. The com- |
mand header "DATE" indicates
the action, the 6 data values specify
it in detail. 1
Header The header is the mnemonic form of the operation to be per-
formed by the oscilloscope. All command
alphabetic order in Section 5.
mnemonicsare listed in |
The majority of the command/queryheaders have a long form for
optimum legibility and a short form for better transfer and decod-
ing speed. The two forms are fully equivalent and can be used
1
interchangeably. For example, the following two commandsfor
switching to the automatic trigger modeare fully equivalent:
TRIG_MODE AUTO and TRMD AUTO
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6
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About Remote Control 2
Some command/query mnemonics are imposed by the IEEE
488.2 standard. They are standardized so that different instru-
ments present the same programming interface for similar
functions. All these mnemonicsbegin with an asterisk <*>, e.g.
the command "*RST" is the IEEE 488.2 imposed mnemonic for
resetting the instrument, whereas "*TST?" instructs the instru-
ment to perform an internal self-test and to report the outcome.

Header path Somecommands queries apply to a sub-section of the oscillo-
or
scope, e.g. a single input channel or a trace on the display. In such
cases, the header must be preceded by a path name that indicates
the channel or trace to which the commandapplies. The header
path normally consists of a 2-letter path name followed by a colon
<:> which immediately precedes the command header.
Usually one of the waveformtraces can be specified in the header
path (refer to the individual commands listed in Section 5 for de-
tails on which values apply to a given commandheader):
C1, C2 Channels 1 and 2
C3, C4 Channels 3 and 4 (in 4-channel instruments)
MC, MD Memory C and D
FE, FF Function E and F
EA, EB Expand A and B
EX, EX10 External trigger

Example CI:OFST -300 MV Set the offset of Channel 1 to
-300 mV
Header paths need only be specified once. Subsequent commands
whose header destination is not indicated are assumed to refer to
the last defined path. For example, the following commandsare
identical:

C2:VDIV?; C2:OFST? Whatis the vertical sensitivity and
the offset of channel 2?
C2:VDIV?; OFST? Same as above, without repeating
the path.

Data Whenever a command/queryuses additional data values, they are
expressed in terms of ASCII characters. There is a single excep-
tion: the transfer of waveforms with the command/query
"WAVEFORM", where the waveform may be expressed as a se-
quence of binary data values. Refer to Section 6 for a detailed
explanation of the format of waveforms.
ASCII data can have the form of character, numeric, string or
block data.
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About Remote Control
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Character data These are simple words or abbreviations for the indication of a
specific action. |
BANDWIDTH LIMIT ON The data value "ON" indicates that
the bandwidth limit should be
turned on, rather than off. |
In some commands, where as many as a dozen different parame-
ters can be specified, or where not all parameters apply at the same
time, the format requires pairs of data values. The first one names
|
the parameter to be modified and the second gives its value. Only
those parameter pairs to be changed need to be indicated.

HARDCOPY_SETUP DEV,HP7470A,PORT,GPIB,PSIZE,A4
|
Three pairs of parameters are spe-
cified. The first specifies the device
as the H7470Aplotter (or compat-
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ible), the second indicates the
GPIB port and the third requests
the A4 format for paper size. While |
the command "HARDCOPY SET-
UP" allows many more parameters,
they are either not relevant for plot-
ters or they are left unchanged.
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Numeric Data The numeric data type is used to enter quantitative information.
Numberscan be entered as integers, as fractions or in exponential
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representation.
EA:VPOS -5 Move the displayed trace of Expand A down- |
wards by 5 divisions.
C2"OFST3.56 Set the DC offset of Channel 2 to 3.56 V.
TDIV5.0E-6 Adjust the time base to 5 issec/div.
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Note: Numeric values may be followed by multipliers and units,
modifying the value of the numerical expression. The following
mnemonics are recognized:
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I About Remote Control 2
EX 1E18 Exa- PE 1E15 Peta-
l T 1E 12 Tera- G 1E9 Giga-
MA 1E6 Mega- K 1E3 kilo-
M 1E-3 milli- U 1E-6 micro-
l N 1E-9 nano- PI 1E-12 pico-
F 1E-15 femto- A 1E-18 atto-

I For example, there are manyways of setting the time base of the
instrument to 5 ~tsec/div:
TDIV 5E-6 Exponential notation, without any
I suffix.
TDIV 5 US Suffix multiplier "U" for 1E-6,
with the (optional) suffix "S" for
l seconds.
TDIV 5000 NS
TDIV 5000E-3 US

String Data This data type enables the transfer of a (long) string of characters
as a single parameter. String data are formed by simply enclosing
any sequence of ASCII characters between simple or double
quotes.
MESSAGE
'Connect probe to point J3'
The instrument displays this message in the Message field above
the grid.

Block Data These are binary data values coded in hexadecimal ASCII, i.e.
4-bit nibbles are translated into the digits 0,...9, A .... F and trans-
mitted as ASCIIcharacters. They are only used for the transfer of
waveforms (command "WAVEFORM") and of the instrument
configuration (command "PANEL_SETUP")

RESPONSE MESSAGE
FORM The instrument sends a response message to the controller, as an
answer to a query. The format of such messages is the same as that
of program messages, i.e. individual responses in the format of
commands, separated by semicolons <;> and ended by a termina-
tor. They can be sent back to the instrument in the form in which
they are received, and will be accepted as valid commands. In
GPIB response messages, the terminator is always
used.
For example, if the controller sends the program message:
TIME_DIV? ;TRIG_MODE NORM;C1 :COUPLING? (terminator
not shown)
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About Remote Control
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the instrument might respond as follows:
TIME_DIV 50 NS;C 1:COUPLING D50 (terminator not shown)
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The response message only refers to the queries,
"TRIG_MODE" left out. If this response is sent back to the
is
i.e.
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instrument, it is a valid programmessagefor setting its time base to
50 nsec/div and the input coupling of Channel 1 to 50 ~.
Whenevera response is expected from the instrument, the control |
program must instruct the GPIB or RS-232-C interface to read
from the instrument. If the controller sends another program mes-
sage without reading the response to the previous one, the
response message in the output buffer of the instrument is dis-
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carded.
The instrument uses somewhatstricter rules for response messages
than for the acceptance of program messages, Whereas the con-
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troller may send program messages in upper or lower case
characters, response messages are always returned in upper case.
Program messages may contain extraneous spaces or tabs (white
|
space), response messages do not. Whereas program messages
may contain a mixture of short and long command/queryheaders,
response messages always use short headers as a default. However, |
the instrument can be forced with the command
"COMM_HEADER"use long headers or no headers at all. If
to
the response header is omitted, the response transfer time is mini- |
mized, but such a response could not be sent back to the
instrument again. In this case suffix units are also suppressed in the
response. |
If the trigger slope of Channel 1 is set to negative, the query
"CI:TRSL?" could yield the following responses:

CI:TRIG_SLOPE NEG header format: long |
CI:TRSL NEG header format: short
NEG header format: off
Waveforms which are obtained from the instrument using the
|
query "WAVEFORM?" constitute a special kind of response mes-
sage. Their exact format can be controlled with the commands
"COMM FORMAT" and "COMM ORDER", as explained in
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Section ~
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10
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3 IGPIB OPERATION
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This section describes howto remotely control the oscilloscope via
the GPIB. Topics discussed include interface capabilities, address-
ing, standard bus commands, and polling schemes.

GPIB STRUCTURE The GPIBis like an ordinary computer bus, except that it inter-
connects independent devices via a cable bus whereas a computer
has its circuit cards interconnected via a backplane bus. The GPIB
carries program messages and interface messages: