Agilent Technologies Infiniium DCA Manual

Agilent Technologies
Infiniium DCA and DCA-J
Agilent 86100A/B/C
Wide-Bandwidth
Oscilloscope
Programmer’s Guide

2
Notices
© Agilent Technologies, Inc. 2000-2007
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Manual Part Number
86100-90092
Edition
March 2007
Printed in Malaysia
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Contents
Contents-1
1Introduction
Introduction 1-2
Starting a Program 1-4
Multiple Databases 1-6
Files 1-8
Status Reporting 1-11
Command Syntax 1-23
Interface Functions 1-34
Language Compatibility 1-36
New and Revised Commands 1-42
Commands Unavailable in Jitter Mode 1-43
Error Messages 1-45
2Sample Programs
C Programming Examples 2-2
BASIC Programming Examples 2-28
3Common Commands
4Root Level Commands
5System Commands
6Acquire Commands
7Calibration Commands
8Channel Commands
9Clock Recovery Commands
10 Disk Commands
11 Display Commands
12 Function Commands

Contents-2
ContentsContents
13 Hardcopy Commands
14 Histogram Commands
15 Limit Test Commands
16 Marker Commands
17 Mask Test Commands
18 Measure Commands
19 S-Parameter Commands
20 Signal Processing Commands
21 TDR/TDT Commands
(Rev. A.05.00 and Below)
22 TDR/TDT Commands
(Rev. A.06.00 and Above)
23 Timebase Commands
24 Trigger Commands
25 Waveform Commands
26 Waveform Memory Commands

1
Introduction 1-2
Starting a Program 1-4
Multiple Databases 1-6
Files 1-8
Status Reporting 1-11
Command Syntax 1-23
Interface Functions 1-34
Language Compatibility 1-36
New and Revised Commands 1-42
Commands Unavailable in Jitter Mode 1-43
Error Messages 1-45
Introduction

1-2
Introduction
Introduction
Introduction
This chapter explains how to program the instrument. The programming syntax conforms to
the IEEE 488.2 Standard Digital Interface for Programmable Instrumentation and to the
Standard Commands for Programmable Instruments (SCPI). This edition of the manual doc-
uments all 86100-series software revisions up through A.07.00. For a listing of commands
that are new or revised, refer to “New and Revised Commands” on page 1-42.
If you are unfamiliar with programming instruments using the SCPI standard, refer to “Com-
mand Syntax” on page 1-23. For more detailed information regarding the GPIB, the IEEE
488.2 standard, or the SCPI standard, refer to the following books:
• International Institute of Electrical and Electronics Engineers. IEEE Standard 488.1-1987,
IEEE Standard Digital Interface for Programmable Instrumentation. New York, NY, 1987.
• International Institute of Electrical and Electronics Engineers. IEEE Standard 488.2-1987,
IEEE Standard Codes, Formats, Protocols and Common commands For Use with ANSI/
IEEE Std 488.1-1987. New York, NY, 1987.
Throughout this book, BASIC and ANSI C are used in the examples of individual commands.
If you are using other languages, you will need to find the equivalents of BASIC commands
like OUTPUT, ENTER, and CLEAR, to convert the examples.
The instrument’s GPIB address is configured at the factory to a value of 7. You must set the
output and input functions of your programming language to send the commands to this
address. You can change the GPIB address from the instrument’s front panel.
Data Flow The data flow gives you an idea of where the measurements are made on the acquired data
and when the post-signal processing is applied to the data. The following figure is a block dia-
gram of the instrument. The diagram is laid out serially for a visual perception of how the
data is affected by the instrument.

1-3
Introduction
Introduction
Figure 1-1. Sample Data Processing
The sample data is stored in the channel memory for further processing before being dis-
played. The time it takes for the sample data to be displayed depends on the number of post
processes you have selected. Averaging your sampled data helps remove any unwanted noise
from your waveform.
You can store your sample data in the instrument’s waveform memories for use as one of the
sources in Math functions, or to visually compare against a waveform that is captured at a
future time. The Math functions allow you to apply mathematical operations on your sampled
data. You can use these functions to duplicate many of the mathematical operations that your
circuit may be performing to verify that your circuit is operating correctly. The measure-
ments section performs any of the automated measurements that are available in the instru-
ment. The measurements that you have selected appear at the bottom of the display. The
Connect Dots section draws a straight line between sample data points, giving an analog look
to the waveform. This is sometimes called linear interpolation.

1-4
Introduction
Starting a Program
Starting a Program
The commands and syntax for initializing the instrument are listed in Chapter 3, “Common
Commands”. Refer to your GPIB manual and programming language reference manual for
information on initializing the interface. To make sure the bus and all appropriate interfaces
are in a known state, begin every program with an initialization statement. For example,
BASIC provides a CLEAR command which clears the interface buffer. When you are using
GPIB, CLEAR also resets the instrument's parser. After clearing the interface, initialize the
instrument to a preset state using the *RST command.
The AUTOSCALE command is very useful on unknown waveforms. It automatically sets up
the vertical channel, time base, and trigger level of the instrument.
A typical instrument setup configures the vertical range and offset voltage, the horizontal
range, delay time, delay reference, trigger mode, trigger level, and slope. An example of the
commands sent to the instrument are:
:CHANNEL1:RANGE 16;OFFSET 1.00<terminator>
:SYSTEM:HEADER OFF<terminator>
:TIMEBASE:RANGE 1E-3;DELAY 100E-6<terminator>
This example sets the time base at 1 ms full-scale (100 μs/div), with delay of 100 μs. Vertical
is set to 16 V full-scale (2 V/div), with center of screen at 1 V, and probe attenuation of 10.
The following program demonstrates the basic command structure used to program the
instrument.
10 CLEAR 707 ! Initialize instrument interface
20 OUTPUT 707;"*RST" !Initialize instrument to preset state
30 OUTPUT 707;":TIMEBASE:RANGE 5E-4"! Time base to 500 us full scale
40 OUTPUT 707;":TIMEBASE:DELAY 25E-9"! Delay to 25 ns
50 OUTPUT 707;":TIMEBASE:REFERENCE CENTER"! Display reference at center
60 OUTPUT 707;":CHANNEL1:RANGE .16"! Vertical range to 160 mV full scale
70 OUTPUT 707;":CHANNEL1:OFFSET -.04"! Offset to -40 mV
80 OUTPUT 707;":TRIGGER:LEVEL,-.4"! Trigger level to -0.4
90 OUTPUT 707;":TRIGGER:SLOPE POSITIVE"! Trigger on positive slope
100 OUTPUT 707;":SYSTEM:HEADER OFF"<terminator>
110 OUTPUT 707;":DISPLAY:GRATICULE FRAME"! Grid off
120 END
• Line 10 initializes the instrument interface to a known state and Line 20 initializes the
instrument to a preset state.
• Lines 30 through 50 set the time base, the horizontal time at 500 μs full scale, and 25 ns of
delay referenced at the center of the graticule.
• Lines 60 through 70 set the vertical range to 160 millivolts full scale and the center screen at

1-5
Introduction
Starting a Program
−40 millivolts.
• Lines 80 through 90 configure the instrument to trigger at −0.4 volts with normal triggering.
• Line 100 turns system headers off.
• Line 110 turns the grid off.
The DIGITIZE command is a macro that captures data using the acquisition (ACQUIRE) sub-
system. When the digitize process is complete, the acquisition is stopped. The captured data
can then be measured by the instrument or transferred to the computer for further analysis.
The captured data consists of two parts: the preamble and the waveform data record. After
changing the instrument configuration, the waveform buffers are cleared. Before doing a
measurement, the DIGITIZE command should be sent to ensure new data has been collected.
You can send the DIGITIZE command with no parameters for a higher throughput. Refer to
the DIGITIZE command in Chapter 4, “Root Level Commands” for details. When the DIGI-
TIZE command is sent to an instrument, the specified channel’s waveform is digitized with
the current ACQUIRE parameters. Before sending the :WAVEFORM:DATA? query to get
waveform data, specify the WAVEFORM parameters. The number of data points comprising a
waveform varies according to the number requested in the ACQUIRE subsystem. The
ACQUIRE subsystem determines the number of data points, type of acquisition, and number
of averages used by the DIGITIZE command. This allows you to specify exactly what the dig-
itized information contains. The following program example shows a typical setup:
OUTPUT 707;":SYSTEM:HEADER OFF"<terminator>
OUTPUT 707;":WAVEFORM:SOURCE CHANNEL1"<terminator>
OUTPUT 707;":WAVEFORM:FORMAT BYTE"<terminator>
OUTPUT 707;":ACQUIRE:COUNT 8"<terminator>
OUTPUT 707;":ACQUIRE:POINTS 500"<terminator>
OUTPUT 707;":DIGITIZE CHANNEL1"<terminator>
OUTPUT 707;":WAVEFORM:DATA?"<terminator>
This setup places the instrument to acquire eight averages. This means that when the DIGI-
TIZE command is received, the command will execute until the waveform has been averaged
at least eight times. After receiving the :WAVEFORM:DATA? query, the instrument will start
passing the waveform information when queried. Digitized waveforms are passed from the
instrument to the computer by sending a numerical representation of each digitized point.
The format of the numerical representation is controlled with the :WAVEFORM:FORMAT
command and may be selected as BYTE, WORD, or ASCII. The easiest method of entering a
digitized waveform depends on data structures, available formatting, and I/O capabilities. You
must scale the integers to determine the voltage value of each point. These integers are
passed starting with the leftmost point on the instrument's display. For more information,
refer to Chapter 25, “Waveform Commands”. When using GPIB, a digitize operation may be
aborted by sending a Device Clear over the bus (for example, CLEAR 707).
NOTE The execution of the DIGITIZE command is subordinate to the status of ongoing limit tests. (See commands
ACQuire:RUNTil on page 6-4, MTEST:RUNTil on page 17-7, and LTEST:RUNTil on page 15-4.) The DIGITIZE
command will not capture data if the stop condition for a limit test has been met.

1-6
Introduction
Multiple Databases
Multiple Databases
Eye/Mask measurements are based on statistical data that is acquired and stored in the color
grade/gray scale database. The color grade/gray scale database consists of all data samples
displayed on the display graticule. The measurement algorithms are dependent upon histo-
grams derived from the database. This database is internal to the instrument’s applications.
The color grade/gray scale database cannot be imported into an external database applica-
tion.
If you want to perform an eye measurement, it is necessary that you first produce an eye dia-
gram by triggering the instrument with a synchronous clock signal. Measurements made on a
pulse waveform while in Eye/Mask mode will fail.
Firmware revision A.03.00 and later allows for multiple color grade/gray scale databases to be
acquired and displayed simultaneously, including
• all four instrument channels
• all four math functions
• one saved color grade/gray scale file
The ability to use multiple databases allows for the comparison of
• channels to each other
• channels to a saved color grade/gray scale file
• functions to the channel data on which it is based
The advantage of acquiring and displaying channels and functions simultaneously is test
times are greatly reduced. For example, the time taken to acquire two channels in parallel is
approximately the same time taken to acquire a single channel.
Using Multiple
Databases in
Remote Programs
Most commands that control histograms, mask tests, or color grade data have additional
optional parameters that were not available in firmware revisions prior to A.03.00. You can
use the commands to control a single channel or add the argument APPend to enable more
than one channel. The following example illustrates two uses of the CHANnel<n>:DISPlay
command.
SYSTem:MODE EYE
CHANnel1:DISPlay ON
CHANnel2:DISPlay ON
The result using the above set of commands, is Channel 1 cleared and disabled while Channel
2 is enabled and displayed. However, by adding the argument APPend to the last command of
the set, both Channels 1 and 2 will be enabled and displayed .
SYSTem:MODE EYE
CHANnel1:DISPlay ON

1-7
Introduction
Multiple Databases
CHANnel2:DISPlay ON,APPend
For a example of using multiple databases, refer to “Multi-Database Example” on page 2-22.
Downloading a
Database
The general process for downloading a color grade/gray scale database is as follows:
1Send the command :WAVEFORM:SOURCE CGRADE
This will select the color grade/gray scale database as the waveform source.
2Issue :WAVeform:FORMat WORD.
Database downloads only support word formatted data (16-bit integers).
3Send the query :WAVeform:DATA?
The data will be sent by means of a block data transfer as a two-dimensional array, 451 words
wide by 321 words high (refer to “Definite-Length Block Response Data” on page 1-26). The
data is transferred starting with the upper left pixel of the display graticule, column by column,
until the lower right pixel is transferred.
4Send the command :WAVeform:XORigin to obtain the time of the left column.
5Send the command :WAVeform:XINC to obtain the time increment of each column.
6Send the command :WAVeform:YORigin to obtain the voltage or power of the vertical center
of the database.
7Send the command :WAVeform:YORigin to obtain the voltage or power of the incremental row.
The information from steps 4 through 7 can also be obtained with the command :WAVe-
form:PREamble.
Auto Skew Another multiple database feature is the auto skew. You can use the auto skew feature to set
the horizontal skew of multiple, active channels with the same bit rate, so that the waveform
crossings align with each other. This can be very convient when viewing multiple eye dia-
grams simultaneously. Slight differences between channels and test devices may cause a
phase difference between channels. Auto skew ensures that each eye is properly aligned, so
that measurements and mask tests can be properly executed.
In addition, auto skew optimizes the instrument trigger level. Prior to auto skew, at least one
channel must display a complete eye diagram in order to make the initial bit rate measure-
ment. Auto skew requires more data to be sampled; therefore, acquisition time during auto
skew is slightly longer than acquisition time during measurements.

1-8
Introduction
Files
Files
When specifying a file name in a remote command, enclose the name in double quotation
marks, such as "filename". If you specify a path, the path should be included in the quotation
marks. All files stored using remote commands have file name extensions as listed in
Table 1-1. You can use the full path name, a relative path name, or no path.
If you do not specify an extension when storing a file, or specify an incorrect extension, it will
be corrected automatically according to the following rules:
• No extension specified: add the extension for the file type.
• Extension does not match file type: retain the filename, (including the current extension) and
add the appropriate extension.
You do not need to use an extension when loading a file if you use the optional destination
parameter. For example, :DISK:LOAD "STM1_OC3",SMASK will automatically add .msk to
the file name. ASCII waveform files can be loaded only if the file name explicitly includes the
.txt extension. Table 1-2 on page 1-9 shows the rules used when loading a specified file.
If you don’t specify a directory when storing a file, the location of the file will be based on the
file type. Table 1-3 on page 1-10 shows the default locations for storing files. On 86100C
instruments, files are stored on the D: drive. On 86100A/B instruments, files are stored on the
C: drive.
When loading a file, you can specify the full path name, a relative path name, or no path
name. Table 1-4 on page 1-10 lists the rules for locating files, based on the path specified.
Standard masks loaded from D:\Scope\masks. Files may be stored to or loaded from any path
external drive or on any mapped network drive.

1-9
Introduction
Files
Table 1-1. File Name Extensions
File Type File Name Extension Command
Waveform - internal format .wfm “STORe” on page 10-9
Waveform - text format (Verbose, XY Verbose,
or Y values)
.txt “STORe” on page 10-9
Pattern Waveform .csv “PWAVeform:SAVE” on page 10-6
Setup .set “STORe” on page 10-9
Color grade - Gray Scale .cgs “STORe” on page 10-9
Jitter Memory .jd “STORe” on page 10-9
Screen image a.bmp, .eps, .gif, .pcx, .ps, .jpg, .tif “SIMage” on page 10-7
Mask .msk, .pcm “SAVE” on page 17-7
TDR/TDT .tdr “STORe” on page 10-9
MATLAB script .m “MATLab:SCRipt” on page 20-5
S-Parameter (Touchstone format) .s1p, .s2p “SPARameter:SAVE” on page 10-8
S-Parameter (text format) .txt “SPARameter:SAVE” on page 10-8
a. For .gif and .tif file formats, this instrument uses LZW compression/decompression licensed under U.S. patent No
4,558,302 and foreign counterparts. End user should not modify, copy, or distribute LZW compression/decompression ca-
pability. For .jpg file format, this instrument uses the .jpg software written by the Independent JPEG Group.
Table 1-2. Rules for Loading Files
File Name Extension Destination Rule
No extension Not specified Default to internal waveform format; add .wfm extension
Extension does not match file type Not specified Default to internal waveform format; add .wfm extension
Extension matches file type Not specified Use file name with no alterations; destination is based on extension
file type
No extension Specified Add extension for destination type; default for waveforms is internal
format (.wfm)
Extension does not match destination
file type
Specified Retain file name; add extension for destination type. Default for
waveforms is internal format (.wfm)
Extension matches destination file
type
Specified Retain file name; destination is as specified

1-10
Introduction
Files
Table 1-3. Default File Locations
File Type Default Location
Waveform - internal format, text format (Verbose, XY Verbose, or Y
values),
D:\User Files\waveforms
Pattern Waveforms D:\User Files\waveforms
Setup D:\User Files\setups
Color Grade - Gray Scale D:\User Files\colorgrade-grayscale
Jitter Memory D:\User Files\jitter data
Screen Image D:\User Files\screen images
Mask C:\Scope\masks (standard masks)
D:\User Files\masks (user-defined masks)
TDR/TDT calibration data (software revision A.05.00 and below) D:\User Files\TDR normalization
TDR/TDT calibration data (software revision A.06.00 and above) D:\User Files\TDR calibration
MATLAB script D:\User Files\Matlab scripts
S-Parameters D:\User Files\S-parameter data
Table 1-4. File Locations (Loading Files)
File Name Rule
Full path name Use file name and path specified
Relative path name Full path name is formed relative to the present working directory, set with the command :DISK:CDIR. The
present working directory can be read with the query :DISK:PWD?
File name with no
preceding path
Add the file name to the default path (D:\User Files) based on the file type. (C drive on 86100A/B
instruments.)

1-11
Introduction
Status Reporting
Status Reporting
Almost every program that you write will need to monitor the instrument for its operating
status. This includes querying execution or command errors and determining whether or not
measurements have been completed. Several status registers and queues are provided to
accomplish these tasks. In this section, you’ll learn how to enable and read these registers.
• Refer to Figure 1-4 on page 1-14 for an overall status reporting decision chart.
• See Figure 1-3 and Figure 1-4 to learn the instrument's status reporting structure which allows
you to monitor specific events in the instrument.
•Table 1-5 on page 1-17 lists the bit definitions for each bit in the status reporting data struc-
ture.
The Status Byte Register, the Standard Event Status Register group, and the Output Queue
are defined as the Standard Status Data Structure Model in IEEE 488.2-1987. IEEE 488.2
defines data structures, commands, and common bit definitions for status reporting. There
are also instrument-defined structures and bits.
To monitor an event, first clear the event, then enable the event. All of the events are cleared
when you initialize the instrument. To generate a service request (SRQ) interrupt to an
external computer, enable at least one bit in the Status Byte Register. To make it possible for
any of the Standard Event Status Register bits to generate a summary bit, the corresponding
bits must be enabled. These bits are enabled by using the *ESE common command to set the
corresponding bit in the Standard Event Status Enable Register. To generate a service
request (SRQ) interrupt to the computer, at least one bit in the Status Byte Register must be
enabled. These bits are enabled by using the *SRE common command to set the correspond-
ing bit in the Service Request Enable Register. These enabled bits can then set RQS and MSS
(bit 6) in the Status Byte Register. For more information about common commands, see
Chapter 3, “Common Commands”.
Status Byte
Register
The Status Byte Register is the summary-level register in the status reporting structure. It
contains summary bits that monitor activity in the other status registers and queues. The Sta-
tus Byte Register is a live register. That is, its summary bits are set and cleared by the pres-
ence and absence of a summary bit from other event registers or queues. If the Status Byte
Register is to be used with the Service Request Enable Register to set bit 6 (RQS/MSS) and to
generate an SRQ, at least one of the summary bits must be enabled, then set. Also, event bits
in all other status registers must be specifically enabled to generate the summary bit that sets
the associated summary bit in the Status Byte Register.
The Status Byte Register can be read using either the *STB? common command query or the
GPIB serial poll command. Both commands return the decimal-weighted sum of all set bits in
the register. The difference between the two methods is that the serial poll command reads

1-12
Introduction
Status Reporting
bit 6 as the Request Service (RQS) bit and clears the bit which clears the SRQ interrupt. The
*STB? query reads bit 6 as the Master Summary Status (MSS) and does not clear the bit or
have any affect on the SRQ interrupt. The value returned is the total bit weights of all of the
bits that are set at the present time.
Figure 1-2. Status Reporting Decision Chart

1-13
Introduction
Status Reporting
The use of bit 6 can be confusing. This bit was defined to cover all possible computer inter-
faces, including a computer that could not do a serial poll. The important point to remember
is that, if you are using an SRQ interrupt to an external computer, the serial poll command
clears bit 6. Clearing bit 6 allows the instrument to generate another SRQ interrupt when
another enabled event occurs. The only other bit in the Status Byte Register affected by the
*STB? query is the Message Available bit (bit 4). If there are no other messages in the Output
Queue, bit 4 (MAV) can be cleared as a result of reading the response to the *STB? query.
If bit 4 (weight = 16) and bit 5 (weight = 32) are set, a program would print the sum of the
two weights. Since these bits were not enabled to generate an SRQ, bit 6 (weight = 64) is not
set.
Figure 1-3. Status Reporting Overview

1-14
Introduction
Status Reporting
Figure 1-4. Status Reporting Data Structures

1-15
Introduction
Status Reporting
Status Reporting Data Structures (continued)

1-16
Introduction
Status Reporting
This BASIC example uses the *STB? query to read the contents of the instrument’s Status
Byte Register when none of the register's summary bits are enabled to generate an SRQ inter-
rupt.
10 OUTPUT 707;":SYSTEM:HEADER OFF;*STB?"!Turn headers off
20 ENTER 707;Result!Place result in a numeric variable
30 PRINT Result!Print the result
40 End
The next program prints 132 and clears bit 6 (RQS) of the Status Byte Register. The differ-
ence in the decimal value between this example and the previous one is the value of bit 6
(weight = 64). Bit 6 is set when the first enabled summary bit is set, and is cleared when the
Status Byte Register is read by the serial poll command.
This example uses the BASIC serial poll (SPOLL) command to read the contents of the
instrument’s Status Byte Register.
10 Result = SPOLL(707)
20 PRINT Result
30 END
Use Serial Polling to Read the Status Byte Register. Serial polling is the preferred method to
read the contents of the Status Byte Register because it resets bit 6 and allows the next
enabled event that occurs to generate a new SRQ interrupt.
Service Request
Enable Register
Setting the Service Request Enable Register bits enables corresponding bits in the Status
Byte Register. These enabled bits can then set RQS and MSS (bit 6) in the Status Byte Regis-
ter. Bits are set in the Service Request Enable Register using the *SRE command, and the
bits that are set are read with the *SRE? query. Bit 6 always returns 0. Refer to the Status
Reporting Data Structures shown in Figure 1-4This example sets bit 4 (MAV) and bit 5 (ESB)
in the Service Request Enable Register.
OUTPUT 707;"*SRE 48"
This example uses the parameter “48” to allow the instrument to generate an SRQ interrupt
under the following conditions:
• When one or more bytes in the Output Queue set bit 4 (MAV).
• When an enabled event in the Standard Event Status Register generates a summary bit that
sets bit 5 (ESB).
Trigger Event
Register (TRG)
This register sets the TRG bit in the status byte when a trigger event occurs. The TRG event
register stays set until it is cleared by reading the register or using the *CLS (clear status)
command. If your application needs to detect multiple triggers, the TRG event register must
be cleared after each one. If you are using the Service Request to interrupt a computer oper-
ation when the trigger bit is set, you must clear the event register after each time it is set.