Tektronix FCA3000, FCA3003, FCA3020, FCA3100, FCA3103 User Manual

...

Download

FCA3000 and FCA3100 Series Timer/Counter/Analyzers

ZZZ

MCA3000 Series Microwave Counter/Analyzers

User Manual

*P077049301*

077-0493-01

FCA3000 and FCA3100 Series Timer/Counter/Analyzers

ZZZ

MCA3000 Series Microwave Counter/Analyzers

User Manual

www.tektronix.com

077-0493-01

Copyright © Tektronix. All rights reserved. Licensed software products are owned by Tektronix or its subsidiaries or suppliers, and are protected by national copyright laws and international treaty provisions.

Tektronix products are covered by U.S. and foreign patents, issued and pending. Information in this publication supersedes that in all previously published material. Speciﬁcations and price change privileges reserved.

TEKTRONIX and TEK are registered trademarks of Tektronix, Inc.

TimeView is a trademark of Pendulum AB.

Contacting Tektronix

Tektronix, Inc. 14150 SW Karl Braun Drive P.O . B ox 50 0 Beaverton, OR 97077 USA

For product information, sales, service, and technical support:

In North America, call 1-800-833-9200. Worl d wide , v i sit www.tektronix.com to ﬁnd contacts in your area.

Warranty

Tektronix warrants that this product will be free from defects in materials and workmanship for a period of three (3) years from the date of shipment. If any such product proves defective during this warranty period, Tektronix, at its option, either will repair the defective product without charge for parts and labor, or will provide a replacement in exchange for the defective product. Parts, modules and replacement products used by Tektronix for warranty work may be n the property of Tektronix.

ew or reconditioned to like new performance. All replaced parts, modules and products become

In order to o the warranty period and make suitable arrangements for the performance of service. Customer shall be responsible for packaging and shipping the defective product to the service center designated by Tektronix, with shipping charges prepaid. Tektronix shall pay for the return of the product to Customer if the shipment is to a location within the country in which the Tektronix service center is located. Customer shall be responsible for paying all shipping charges, duties, taxes, and any other charges for products returned to any other locations.

This warranty shall not apply to any defect, failure or damage caused by improper use or improper or inadequate maintenance and care. Tektronix shall not be obligated to furnish service under this warranty a) to repair damage result b) to repair damage resulting from improper use or connection to incompatible equipment; c) to repair any damage or malfunction caused by the use of non-Tektronix supplies; or d) to service a product that has been modiﬁed or integrated with other products when the effect of such modiﬁcation or integration increases the time or difﬁculty of servicing the product.

THIS WARRANTY IS GIVEN BY TEKTRONIX WITH RESPECT TO THE PRODUCT IN LIEU OF ANY OTHER WARRANTIES, EXPRESS OR IMPLIED. TEKTRONIX AND ITS VENDORS DISCLAIM ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

TRONIX’ RESPONSIBILITY TO REPAIR OR REPLACE DEFECTIVE PRODUCTS IS THE SOLE

TEK AND EXCLUSIVE REMEDY PROVIDED TO THE CUSTOMER FOR BREACH OF THIS WARRANTY. TEKTRONIX AND ITS VENDORS WILL NOT BE LIABLE FOR ANY INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES IRRESPECTIVE OF WHETHER TEKTRONIX OR THE VENDOR HAS ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES.

[W4 – 15AUG04]

btain service under this warranty, Customer must notify Tektronix of the defect before the expiration of

ing from attempts by personnel other than Tektronix representatives to install, repair or service the product;

Table of Contents

General Safety Summary ......................................................................................... iii

Preface ............................................................................................................... v

About This Manual ... ................................ ................................ ......................... v

Features .......... .................................. ................................ ............................. v

Powerful and Versatile Functions ........................................................................... vi

No Mistakes ................................................................................................... vi

Design Innovations .......................................................................................... vii

Remote Control ............... ................................ ................................ ............... vii

Unpacking ........................................................................................................... 1

Standard Accessories.......................................................................................... 1

Identiﬁcation ................................................................................................... 1

Installation ............................. ................................ ................................ ......... 1

Getting Acquainted with Your Instrument ... ... . . .. . ... ... . .. . ... ... ... . ... ... ... . ... ... ... . ... ... ... . ... ... ... . 3

Front Panel ................ .................................. ................................ ................... 3

Input Connectors............................................................................................... 4

Rear Panel ... ................................ .................................. ................................ . 5

Main Screen .................................................................................................... 6

Controls...................... ................................ .................................. ................ 10

Entering Numeric Values .................................................................................... 14

Menus .......................................................................................................... 14

Input Signal Conditioning .. ... . ... ... . . .. . ... ... . ... ... . . .. . ... ... . ... ... . . .. . ... ... . ... ... ... . ... ... . . .. . ... ... . 21

Input Controls ................................................................................................. 21

How to Reduce or Ignore Noise and Interference............................... .......................... 26

Frequency Measurements....................... ................................ .................................. 31

Theory of Measurement...................................................................................... 31

Input A, B...................................................................................................... 36

Input C ........... ................................ ................................ .............................. 38

Ratio A/B, B/A, C/A, C/B ..................... ................................ .............................. 38

Burst A, B, C .................... ................................ .................................. ............ 38

Frequency Modulated Signals............................................................................... 41

AM Signals.................................................................................................... 44

Period .................. ................................ .................................. ...................... 46

Frequency...................................................................................................... 47

Time Measurements ............................................................................................... 48

Introduction.................................................................................................... 48

Time Interval .................... ................................ .................................. ............ 49

Rise/Fall Time A/B ........................................................................................... 49

Time Interval Error (TIE) (FCA3100 Series Only) ........... ................................ ............ 50

Pulse Width A/B .............................................................................................. 51

FCA3000, FCA3100, and MCA3000 Series User Manual i

Table of Contents

Duty Factor A/B

........................ ................................ ................................ ...... 51

Time Measurement Errors ................................................................................... 52

Phase Measurements .............................................................................................. 54

Resolution ......... .................................. ................................ .......................... 55

Possible Errors .............. ................................ ................................ .................. 55

Totalize (FCA3100 Series Only).................. ................................ .......................... 59

Voltage Mea

surements ............................................................................................ 63

MAX,VMIN

RMS

,andVPP.......................................................................................... 63

........................ ................................ ................................ .................... 63

Math and Statistical Measurements.............................................................................. 65

Averaging...................................................................................................... 65

Mathematics................. .................................. ................................ ................ 65

ics ..... .................................. ................................ ................................ 66

Statist

Limit Testing........... ................................ ................................ ............................ 71

Arming.......................................... .................................. ................................ .. 73

Guidelines ..................................................................................................... 73

Start and Stop Arming.................................. ................................ ...................... 74

Arming Input Signals......................................................................................... 75

ng and Setup Time.......................................... ................................ ............ 76

Armi

Arming Examples............................................................................................. 77

Arming and Proﬁling ................. .................................. ................................ ...... 82

Appendix A: Default Instrument Settings . ... ... ... . ... ... ... ... . .. . ... ... ... . ... ... ... .. .. . ... ... ... .. .. . ... .. 85

Appendix B: Controlling Measurement Timing.. ... . .. . ... ... ... . ... ... ... .. .. . ... ... ... . ... ... ... .. .. . ... ... . 87

The Measurement Process ................................................................................... 87

dex

ii FCA3000, FCA3100, and MCA3000 Series User Manual

General Safety Summary

Review the following safety precautions to avoid injury and prevent damage to this product or any products connected to it.

To avoid potential hazards, use this product only as speciﬁed.

Only qualiﬁed personnel should perform service procedures.

While using this product, you may need to access other parts of a larger system. Read the safety sections of the other component manuals for warnings and cautions related to operating the system.

To Avoid Fire or Personal

Injury

Use proper power cord. Use only the power cord speciﬁed for this product and

certiﬁed for the country of use.

Connect and disconnect properly. Do not connect or disconnect probes or test leads while they are connected to a v oltage source.

Ground the product. This product is grounded through the grounding conductor of the power cord. To avoid electric shock, the grounding conductor must be connected to earth ground. Before making connections to the input or output terminals of the product, ensure that the product is properly grounded.

Observe all terminal ratings. To avoid ﬁre or shock hazard, observe all ratings and markings on the product. Consult the product manual for further ratings information before making connections to the product.

The inputs are not rated for connection to mains or Category II, III, or IV circuits.

Do not apply a potential to any terminal, including the common terminal, that exceeds the maximum rating of that terminal.

Power disconnect. The power cord disconnects the product from the power source. Do not block the power cord; it must remain accessible to the user at all times.

Do not operate without covers. Do not operate this product with covers or panels removed.

Do not operate with suspected failures. If you suspect that there is damage to this product, have it inspected by qualiﬁed service personnel.

Avoid exposed circuitry. Do not touch exposed connections and components when power is present.

Do not operate in wet/damp conditions.

Do not operate in an explosive atmosphere.

Keep product surfaces clean and dry.

Provide proper ventilation. Refer to the manual’s installation instructions for

details on installing the product so it has proper ventilation.

FCA3000, FCA3100, and MCA3000 Series User Manual iii

General Safety Summary

TermsinThisManual

Symbols and Terms on the

Product

These terms may

WARNING. Warning statements identify conditions or practices that could result

in injury or loss of life.

CAUTION. Caution statements identify conditions or practices that could result in

damage to this product or other property.

These terms may appear on the product:

DANGER in the marking.

WAR NI NG read the marking.

CAUTIO

The following symbol(s) may appear on the product:

appear in this manual:

dicates an injury hazard immediately accessible as you read

indicates an injury hazard not immediately accessible as you

N indicates a hazard to property including the product.

iv FCA3000, FCA3100, and MCA3000 Series User Manual

Preface

About This Manual

This manual contains operation information for the FCA3000 and FCA3100 Series Timer/Counter/Analyzer and the MCA3000 Series Microwave Counter/Analyzer.

To simplify the references, features that are common to all instruments are not marked with instrument names. Features that are speciﬁc to a particular instrument or instrument series are clearly marked.

Instrument references:

FCA3X00 meansanyFCA3000SeriesorFCA3100Seriesinstrument

FCA3000 means any FCA3000 Series instrument (FCA3000, FCA3003,

FCA3020)

FCA3100 means any FCA3100 Series instrument (FCA3100, FCA3103, FCA3120)

MCA3000 means any MCA3000 Series instrument (MCA3027 or MCA3040)

Features

Wide measurement frequency range to 40 GHz

Fastest microwave counter on the market (25 ms acquisition time)

Industry’s only frequency counter with a graphical display

High resolution down to 50 ps single shot (time), or 12 digits/s (frequency)

Simultaneous display of signal frequency and voltage parameters

Trigger sensitivity of 15 m V

Voltage resolution to 1 mV

Fast USB/GPIB bus transfer speeds, up to 15 k measurements per second (block mode)

Zero-dead time frequency/period measurements

Best Oven-controlled Crystal Oscillator (OCXO) time base options (1.5E-8/year)

MCA3000 Series offers microwave CW frequency measurements and very short burst measurements down to 40 ns

Programmable Pulse output from 0.5 Hz to 50 MHz (FCA3100 Series)

from DC to 200 MHz

rms

10 MHz reference output oscillator

FCA3000, FCA3100, and MCA3000 Series User Manual v

Preface

Measurement St

Front or rear input connection options

Powerful and Versatile Functions

A unique performance feature in your new instrument is the comprehensive arming poss complex signal concerning frequency and time.

For instan the actual arming of the instrument. Read more about Arming in Chapter 5, Measurement Control.

In addition to the traditional measurement functions of a timer/instrument, these instruments have a multitude of other functions such as phase, duty factor, rise/fall time, and peak voltage. The ins t rument can perform all measurement functions on both Input A and Input B. Most measurement functions can be armed, either using one of the main inputs or using a separate arming channel (E).

By using the built-in mathematics and statistics functions, the instrument can process the measurement results in the instrument, without the need for an

nal controller o r software. Math functions include inversion, scaling, and

exter offset. Statistics functions include Max, Min and Mean, Standard deviation, and Allan deviation, on sample sizes up to 2*10

ibilities, which allow you to characterize virtually any type of

ce, you can insert a delay between the external arming condition and

atistics, Histogram, and Trend Plot modes

No Mistakes

You will soon ﬁnd that your instrument is more or less self-explanatory with an intuitive user interface. A menu tree with few levels makes the timer/instrument easy to operate. The large backlit graphic LCD is the center of information and can show you several signal parameters at the same time as well a s setting status

d operator messages.

Statistics based on measurement samples can easily be presented as histograms or

rend plots in addition to standard numerical measurement results like max, min,

t mean, and standard deviation.

The AUTO function triggers automatically on any input waveform. A bus-learn mode simpliﬁes GPIB programming. With bus-learn mode, manual instrument settings can be transferred to the controller for later reprogramming. There is no need to learn code and syntax for each individual instrument setting if you are an occasional bus user.

vi FCA3000, FCA3100, and MCA3000 Series User Manual

Design Innovations

Preface

State of the Art Technology

Gives Durable Use

High Resolution

These counters are designed for quality and durability. The design is highly integrated. The digital counting circuitry consists of just one custom-developed FPGA and a 32-bit microcontroller. The high integration and low component count reduces power consumption and results in an MTBF of 30,000 hours. Modern surf mechanical construction, including a metal cabinet that withstands mechanical shocks and protects against EMI, is also a valuable feature.

The use of excellent relative resolution of 12 digits/s for all frequencies.

The meas base. Simultaneously with the normal “digital” counting, the instrument takes analog measurements of the time between the start/stop trigger events and the next following clock pulse. This is done in four identical circuits by charging an integrating capacitor with a constant current, starting at the trigger event. Charging is stopped at the leading edge of the ﬁrst following clock pulse. The

d charge in the integrating capacitor represents the time difference between

store the start trigger event and the leading edge of the ﬁrst following clock pulse. A similar charge integration is made for the stop trigger event.

When the “digital” part of the measurement is ready, the stored charges in the capacitors are measured by Analog/Digital Converters.

ace-mount technology ensures high production quality. A rugged

reciprocal interpolating counting in this instrument results in an

urement is synchronized with the input cycles instead of the time

Remote Control

The instrument calculates the result after completing all measurements, that is, the digital time measurement and the analog interpolation measurements. The result is that the basic digital resolution of ±1 clock pulse (10 ns) is reduced to 100 ps for the FCA3000 Series and 50 ps for the FCA3100 Series.

Since the measurement is synchronized with the input signal, the resolution for frequency measurements is very high and independent of frequency. The counters have 14 display digits so that the display itself does not restrict the resolution.

This instrument is programmable using two interfaces, GPIB and USB.

The GPIB interface offers full general functionality and compliance with the latest standards in use, the IEEE 488.2 1987 for HW and the SCPI 1999 for SW. There is also a second GPIB mode that emulates the Agilent 53131/132 command set for easy exchange of instruments in operational ATE systems.

The USB interface is mainly intended for use with the optional TimeView™ analysis software. The communication protocol is a proprietary version of SCPI.

FCA3000, FCA3100, and MCA3000 Series User Manual vii

Preface

Fast GPIB Bus

These counters also feature fast bus communications. The bus transfer rate is up to 2000 triggered measurements/s. Array mea surements to the internal memory can reach 250 k measurements/s.

This very high measurement rate makes new measurements possible. For example, you can perform jitter analysis on several tens of thousands of pulse width measurements and capture them in a second.

An extensive Programmer Manual describes the available SCPI-based programming commands.

The instrument is easy to use in GPIB environments. A built-in bus-learn mode enables you to make all instrument settings manually and transfer them to the controller. The response can late r be used to reprogram the instrument to the same

s. This eliminates the need for the occasional user to l earn all individual

setting programming codes.

Comple memory locations and can easily be recalled. Ten of the internal memory locations can be user protected.

te (manually set) instrument settings canalsobestoredin20internal

are not only extremely powerful and versatile instruments, they

viii FCA3000, FCA3100, and MCA3000 Series User Manual

Unpacking

Standard Accessories

Identiﬁcation

Check that the shipment is complete and that no damage has occurred during transportation. If the contents are incomplete or damaged, ﬁle a claim with the carrier immediately. Also notify your local Tektronix representative in case repair or replacement is required.

See the FCA3000, FCA3100 Series Timer/Counter/Analyzer and MCA3000 Series

Microwave

accessories.

The identiﬁcation label on the rear panel shows instrument model, serial number, and conﬁguration information. (See page 5, Rear Panel.) You can also push User Opt > About to display instrument information.

Counter/Analyzer Quick Start User Manual for a list of standard

Installation

Suppl

y Voltage

You can connect the instrument to an AC supply with a voltage rating of 90-265 V line voltage.

There is no user-serviceable fuse for the FCA3X00 or MCA3000 Series instruments.

TION. If this fuse is blown, it is likely that the power supply is badly damaged.

CAU

Do not replace the fuse. Send the instrument to a Tektronix Service Center. Removing the cover for repair, maintenance and adjustment must be done only by qualiﬁed and trained personnel, who are fully aware of the hazards involved.

The warranty commitments are rendered void if unauthorized access to the interior of the instrument has taken place during the given warranty period.

, 45-440 Hz. The instrument automatically adjusts itself to the input

rms

FCA3000, FCA3100, and MCA3000 Series User Manual 1

Unpacking

ation and Cooling

Orient

Grounding

Grounding faul it dangerous. Before connecting any unit to the power line, you must make sure that the protective ground functions correctly. Only then can a unit be connected to the power line and only by using a three-wire line cord. No other method of grounding is permitted. Extension cords must always have a protective ground conductor.

CAUTION. If

may cause a shock hazard. Allow the instrument several hours to evaporate condensation before use. Make s ure that the instrument grounding requirements are strictly met.

WARNING. Never interrupt the grounding cord. Any interruption of the protective

ground connection inside or outside the instrument or disconnection of the protective ground terminal can result in a shock hazard.

You can operate the instrument in any position. Do not obstruct the air ﬂow through the ventilation slots on the side panels: leave 5 centimeters (2 inches) of space on the sides and back of the instrument. The instrument also h as fold-down

or benchtop use.

legs f

ts in the line voltage supply will make any instrument connected to

a unit is moved from a cold to a warm environment, condensation

2 FCA3000, FCA3100, and MCA3000 Series User Manual

Getting Acquainted with Your Instrument

Front Panel

1. Power button (See page 10, Power Button.)

2. Main sc

3. Measurement buttons (See page 10, Measure Button.)

4. Navigation buttons (See page 11, Save/Exit Button.)

5. Input connectors (See page 4, Input Connectors.)

6. Keypad buttons (See page 12, Keypad Buttons.)

reen (See page 6, Main Screen.)

FCA3000, FCA3100, and MCA3000 Series User Manual 3

Getting Acquainted with Your Instrument

Input Connect

ors

1. Input A and B inputs and trigger indicators. A blinking trigger LED shows correct triggering.

2. Gate indicator. The GATE indicator is on when the counter is busy counting input cycles.

3. Input C prescaler (3 GHz or 20 GHz, FCA3000 and FCA3100 Series) or down converter (27 GHz or 40 GHz, MCA3000 Series) for measuring higher frequencies.

NOTE. Factory Option RP moves the input connectors from the front panel to the

anel for FCA3000 Series and FCA3100 Series instruments. The Gate and

rear p Trig A/B LED indicators remain on the front panel. Option RP is not available on MCA3000 Series instruments.

4 FCA3000, FCA3100, and MCA3000 Series User Manual

Rear Panel

Getting Acquainted with Your Instrument

1. Pulse Out

2. ID label, including model, serial, and installed options numbers.

3. Line power connector.

4. USB 2.0 12 Mb/s port to connect to PC.

5. GPIB port to connect to controller.

6. Optional rear panel input connectors. Factory Option RP moves the front

panel input connectors to the rear panel. Not available for MCA3000 Series instruments.

7. External Arm Input connector (for external arming (synchronization) of measurements). You can also select Input A and Input B for measurement arming from the Settings Menu.

8. External Reference Input connector. If the Measurement Reference is set to Auto in the Settings Menu, this input is automatically selected, provided a valid signal is present.

9. 10 MHz Out connector. Provides a reference signal derived from the active measurement reference (internal or external reference). The measurement

eference source is set in the Settings Menu.

put connector (FCA3100 Series only).

FCA3000, FCA3100, and MCA3000 Series User Manual 5

Getting Acquainted with Your Instrument

Main Screen

The instrument uses a monochrome LCD to show signal sources, instrument measurements (numerical and graphical), and menu items. What items are shown depends on th

Measurement Value Mode

Push the Value button to display a high-resolution numeric readout of the current measurement.

1. The current measurement.

edisplaymode.

2. The measurement signal source. If the main measurement readout is a statistical measurement, this text also shows the type of statistical measurement (for example, A MEAN:)

3. The main measurement readout. The readout at the bottom of the scree n shows electrical information for the source signal. The readouts or display changes depending on the measurement or analysis mode.

4. Measurement status. Shows the math or limit testing mode (MATH or LIM), the measure/hold/single measu remote GPIB control status (REM). The measurement status is present in all display modes.

NOTE. Normally the screen shows the active measurement when the instrument

is remotely controlled. However, TimeView turns off the screen to speed up measurements: the screen displays the message Display OFF, the measurement status is REM (remote), and a the Esc button to send a “Return To Local” message to the remote device and return the instrument to local mode.

You cannot use the Esc key to return the instrument to local mode if Local Lockout was programmed from the remote connection.

rement status (MEAS, HOLD, SING), and

ll front panel buttons except Esc are disabled. Push

5. Limit Alarm readout (when enabled). Lower limit (LL) and upper limit (UL) settings are shown as vertical bars with their associated limit value. An emoticon shows the relative measurement value and limit pass/fail state (a smiling face when the measurement is within the limits, and a frowning

6 FCA3000, FCA3100, and MCA3000 Series User Manual

Getting Acquainted with Your Instrument

Menu Mode

face when the me the top of the screen ﬂashes when the measurement exceeds the limits, and continues to ﬂash even when the measurement is back within limits. Pushing Restart resets the LIM status.

Pushing a menu button (such as Meas or any of the lower keypad buttons) replaces the lower screen area with the menu items for that button.

1. The Menu path shows the path of the current menu selections.

2. TheMenushowstheavailablemenuoptions. Push the keypad button directly

below a menu item to select that item and/or open a lower-level menu. The current selection is shown in inverse text. You can also use the Navigation arrow buttons to highlight and select menu items.

asurement is outside of the limits). The LIM status text at

Analyze Modes

The Analyze modes (accessible by p statistical analysis to display numerical, histogram, or trend statistical analysis readouts of measurements.

Numerical display. The instrument takes successive measurements and displays the results as numeric statistical readouts.

MEAN: The main measurement shows the running mean value over N samples

N: The number of measurement sampl es (set in the Settings > Stat menu)

Max, Min: The maximum and minimum measurement values

P-P: Peak-to-peak deviation

ushing the Analyze button) apply basic

FCA3000, FCA3100, and MCA3000 Series User Manual 7

Getting Acquainted with Your Instrument

Adev: Allan dev

Std: Standard deviation

Histogram display. The instrument displays successive measurements as a histogram. The number of bins along the horizontal axis are set in the Settings

>Statmenu.

1. The upper and lower Limits Alarm levels (if enabled). When limit testing is

active, the instrument autoscales the graph to show both the histogram and the limit. The instrument only uses data inside the limits for autoscaling; measurements outside the visible graph area are shown by an arrowhead a t

ft or the right edge of the display.

the le

iation

2. The running mean measurement position (X

3. The percent of the measurement completed.

4. The graph center (marked with a dark triangle) and corresponding frequency.

5. The graph horizontal scale per division. Limits Alarm (if active) sets the scale

to show both the current measurements and the limit settings. The instrument continually autoscales the histogram bins based on the measured data.

end plot display. The instrument t akes successive measurements and plots the

values over time. This mode is useful for observing ﬂuctuations or measurement deviation trends. A trend plot stops (if HOLD is activated) or restarts (if RUN is activated) after the set number of samples is completed. The trend plot graph continually autoscales based on the measured data, starting with zero at restart. Limit Alarms, if active, are shown as horizontal lines.

8 FCA3000, FCA3100, and MCA3000 Series User Manual

Getting Acquainted with Your Instrument

1. The upper and lower frequency range of the plot display. The trend plot graph continually autoscales based on the measured data to show the measurement trend values.

2. The percent of the measurement completed.

3. The horizontal units per division.

4. The Limits Alarm levels (if active). When limit testing is active, the

instrument sets the graph scale to show both the measurement trend plot and the limit values (horizontal dashed lines).

FCA3000, FCA3100, and MCA3000 Series User Manual 9

Getting Acquainted with Your Instrument

Controls

Power Button

Measure Button

Push the Powe button is a secondary power switch; power is applied to some of the instrument as soon as line power is applied, indicated by the red LED above the button. To completely remove power from the instrument, disconnect the power cord.

Use the Meas button to display the instrument measurement menu along the bottom of the screen. Press a menu button directly below a menu item to select that menu item and open a sub-menu as needed.

Typical measurements include frequency, period, time, pulse, phase, totalize (FCA3100 Series only), and volts. The measurement menu content depends on the instrument model and conﬁguration.

The current selection is indicated by text inversion (and that also indicates the cursor position). Select the measurement function you want by pushing the corresponding menu softkey below a menu item.

r button to power on or off the instrument. The Power

Value Button

Analyze Button

You can also use the Left and Right arrow buttons to mo other menu items. Conﬁrm by pushing Enter.

Use the Va lue button to display the current measurement as a numerical value. The instrument also displays supplementary measurements along the lower part of the screen.

Use the Analyze button to display the current measurement in one of three statistical analysis display modes. Repeatedly press the Analyze button to cycle through the statistical display modes. (See page 7, Analyze Modes.)

ve the cursor and select

10 FCA3000, FCA3100, and MCA3000 Series User Manual

Auto Set Button

Getting Acquainted with Your Instrument

Use the Auto Set button to automatically set trigger levels for the measurement function and input signal amplitude (for relatively normal signals). This enables you to quickly set the instrument to d isplay a measurement.

Pushing the Autoset button once does the following:

Sets automatic trigger levels

Sets attenu

Turns on the display

Sets the Auto Trig Low Freq value to one of the following:

100 Hz, if fin≥100 Hz

fin,if10<fin< 100 Hz

10 Hz, if fin≤10 Hz

Pushing Preset. The following parameters are set in addition to the single push Autoset functions:

Sets Meas Time to 200 ms

Switc

Sets Hold/Run to Run

Switches off Math/Limit

Switches off Analog and Digital Filters

Sets theTimebase Ref to Auto

ators to 1x

the Autoset button twice within two seconds performs a more extensive

hes off Hold-Off

Switches off Arming

even more comprehensive preset function can be performed by recalling the

An factory default settings.

Save/Exit Button

Use the Save/Exit buttontoconﬁrm the current selection and exit to the previous menu level.

Esc Button

Use the Esc button to exit to the previous menu level without conﬁrming

the current selection.

FCA3000, FCA3100, and MCA3000 Series User Manual 11

Getting Acquainted with Your Instrument

Arrow and Enter

Keypad Buttons

Buttons

The Arrow and Enter buttons provide multiple functions depending on the instrument mode:

Menu mode: Use the left-arrow, right-arrow, and Enter buttons to display and select menu items.

Numeric entry mode: Use the left-arrow button to clear the right-most digit in a settings ﬁeld. Use the up- and down-arrow buttons to increment or decrement a numeric value in a settings ﬁeld (in a 1-2-5 pattern).

Use the Enter button to accept the displayed value or selected menu item.

LCD screen contrast: Use the up- and down-arrow buttons to set the LCD screen contrast when the instrument is not dis playing a menu or prompting for input.

Use the keypad buttons to select menu items, open instrument conﬁguration menus, and enter parameter values.

Use the Numeric buttons (buttons 0-9, ., and ±) to enter numeric parameter values in parameter ﬁelds.

Use the Menu Softkey buttons (buttons 1-5 and the two blank buttons on the top row) to select the correspondingscreenmenuitems.

Use the Menu buttons (Input A through User Opt, on the bottom row of the keypad) to display the menu for that button.

Input A, Input B. Use the Input A and Input B buttons to display and conﬁgure the input channel settings for the selected channel. The Input A and Input B menu provides channel-related settings, including trigger slope, signal coupling (AC or DC), input impedance (50 Ω or 1 MΩ), input attenuation (1x or 10x), trigger mode (Manual or Auto), Trigger level (when in Manual trigger mode), and Filter (frequency cutoff). The Input A and B menus are identical.

12 FCA3000, FCA3100, and MCA3000 Series User Manual

Getting Acquainted with Your Instrument

To set a speciﬁc menu item, and use the Navigation arrow buttons to increment/decrement the value. You can also use the numeric buttons and push Enter to enter a value.

The Filter Settings menu lets you select a ﬁxed 100 kHz analog ﬁlteroran adjustable digital ﬁlter. The equivalent cutoff frequency is set using the value input menu that opens if you select Digital LP Frequency from the menu.

NOTE. Always use Auto trigger level when measuri ng rise time or fall time.

Settings. Use the Settings button to display the measurement settings conﬁguration menu. The Settings menu provides measurement-related settings, including Measure Time (for frequency measurements), Burst (for pulse-m Holdoff (stop trigger delay), Statistics (settings for statistical measurements), Time base Reference (internal or external), and Miscellaneous (such as input signal timeout period and auto trigger low frequency setting).

Math/Limit. Use the Math/Limit button to display the math and limit testing conﬁg user-deﬁned constants to mathematically postprocess the measurement result. A typical use for math processing is to convert a measurement to take into account a mixer or multiplier that is part of the signal under test.

odulated signals), Arming (conditional measurement start/stop), Trigger

uration menus. The Math menu provides predeﬁned formulas and

trigger level, select the Manual trigger mode, select the Tr i g

The Limits menu lets you set numerical limits and select how the instrument reports limit violations.

User Opt. Use the User Opt button to display the user options conﬁguration

nu. The User Options menu provides instrument settings, including saving or

me recalling instrument setups (up to twenty in nonvolatile memory, each with a unique label), bus interface selection (USB or GPIB), GPIB bus conﬁguration (mode, address), instrument self-tests, conditional output signal setup (FCA3100 Series only), and instrument conﬁ guration information (model, serial number, ﬁrmware, and conﬁguration).

The User Options menu also provides an instrument calibration function. This internal calibration process requires password access. See the FCA3000 and

FCA3100 Series Timer/Counter/Analyzers and MCA3000 Series Microwave Counter/Analyzers Technical Reference Manual for instructions on how to do an

internal instrument calibration.

Hold/Run. Use the Hold/Run button to control measurement acquisition. Press the button to toggle between run (constantly acquiring measurements) and hold (measurement pause) modes. The measurement indicator in the upper right corner of the screen changes from MEAS to HOLD when the instrument is in the measurement hold mode. Push the Hold/Run button again to resume the normal (continuous) measurement mode.

FCA3000, FCA3100, and MCA3000 Series User Manual 13

Getting Acquainted with Your Instrument

To take a single the Restart button. The measurement indicator in the upper right corner of the screen changes from HOLD to SING when the instrument is taking a single measurement.

Restart. Use the Restart button to clear the measurement values and retake a measurement. This is useful when you need to initiate a new measurement after a change in the input signal, especially when using long measuring times. When the instrument is in the Hold mode, use this button to take single measurements.

Restart does not affect any instrument settings.

Entering Numeric Values

Sometimes you might need to enter constants and limits in a menu ﬁeld. You may also want to select a value that is not in the list of ﬁxed values available by pressing the Up/Down arrow buttons, or the value to enter is too far away to reach conveniently by incrementing or decrementing the original value.

To enter numeric values, use the numeric buttons (0-9, . (decimal point), and ± (change sign).

You can also enter values using the scientiﬁc notation format. The EE (Enter Exponent) softkey lets you toggle between entering the mantissa and the exponent.

measurement, place the instrument in Hold mode, and then press

Menus

Input A, Input B Menus

Push Save|Exit to store the new value or Esc to exit this menu without saving the value (retains the current value).

The Input A and Input B menus provides settings for conﬁguring each channel. The contents of the Input A and Input B menus are identical.

Table 1: The Input A, Input B menus

Item Description

Slope Trigger on rising or falling edge of a signal.

Signal coupling AC or DC.

Input impedance

Input signal attenuation

Trigger Mode

1MΩ or 50 Ω.

1x or 10x.

Sets the signal trigger level mode (Auto or Man). If i n Auto trigger mode, use the Trig menu item to set the trigger level manually as a percentage of the amplitude. If in Man trigger mode, use the Trig menu item to enter a trigger value.

NOTE. Always use Auto when measuring rise time or fall time.

14 FCA3000, FCA3100, and MCA3000 Series User Manual

Getting Acquainted with Your Instrument

Table 1: The Input A, Input B menus (cont.)

Item Description

Trig

Filter

Sets the signal trigger level. The value shown is the current trigger level.

Sets a ﬁxed 100 kHz analog or an adjustable digital cutoff ﬁlter. Use the Digital LP Frequency menu to set a speciﬁc frequency.

Settings Menu

Use the Settings menu to conﬁgure the measurement parameters.

Tabl e 2: T

Item Description

Meas Time

Burst

Arm

Trigger Hold Off

Stat Sets statistics m easurement parameters:

he Settings menu

Sets the measurement duration. This menu is available for frequency measurements. Longer measuring time means fewer measurements per second and gives higher resolution.

Sets parameters related to pulse-modulated (burst) signal measurements. The Burst settings menu is available if the selected measurement is Meas >Freq>FreqBurst. Both the carrier frequency and the modulating frequency (the pulse repetition frequency (PRF)) can be measured, often without the support of an external arming signal.

Sets measurement start and stop parameters. Arming is the general term used for the means to control the actual start and stop time of a measurement. The normal free-running mode is inhibited and triggering takes place when speciﬁed pretrigger conditions are detected.

The s ignal or signals used for initiating the arming can be applied to three channels (A, B, or E), and the start channel can be different from the stop channel. All conditions can be set by using this menu.

Sets the delay during which the stop trigger conditions are ignored after the measurement start. A typical use is to bypass signals generated by bouncing relay contacts.

The number of samples used for calculation of various statistical

measures.

The number of bins in the histogram view.

Enables Pacing (the delay between measurements) ON or O FF, and

sets the delay time from 2 μs – 500 s.

Timebase

Sets an Internal or an External time base reference for measurements. A third alternative is Auto. Then the external time base is selected if a valid signal is present at the reference input. The EXT REF indicator at the upper right corner of the screen shows that the instrument is using an external time base reference.

FCA3000, FCA3100, and MCA3000 Series User Manual 15

Getting Acquainted with Your Instrument

Table 2: The Settings menu (cont.)

Item Description

Misc

Sets miscellaneous measurement parameters:

Interpolator Calibration enables or disables the instrument interpolator calibration, which increases the measurement speed at the expense of accuracy.

Smart Measure sets:

Smart Time Interval (for Time Interval measurements), which uses

time stamping to determine which measurement channel precedes the other.

Smart Frequency (for Frequency or Period Average measurements), which uses continuous time stamping and regression analysis to increase the resolution for measuring times between 0.2 s and 100 s.

Timeout enables or disables the timeout function and sets the maximum time the instrument will wait for a pending measurement to ﬁnish before outputting a zero result. The range is 10 ms to 1000 s.

Auto Trig Low Freq sets the lower frequency limit for automatic triggering and voltage measurements within the range 1 Hz to 100 kHz. A higher limit means faster settling time and faster measurements.

Input C Acq (MCA3000 Series only) sets:

Acquisition mode to Auto (scan the entire speciﬁed frequency range

for valid input signals) or Manual (scan a narrow band around a speciﬁed center frequency for valid input signals). Manual mode is required when measuring burst signals but is also recommended for FM signals, when the approximate frequency is known. An additional feature of manual mode is that the measurement results are presented much faster, as the acquisition process is skipped.

Note that signal frequencies outside the manual capture range may cause wrong results. To draw the operator’s attention to this possibility, the instrument shows the indicator M.ACQ in the upper right corner of the screen.

Freq C Center value.

TIE (Time Interval Error) (FCA3100 Series only) sets the instrument to

choose the reference frequency automatically (Auto) or manually enter a frequency (Manual). TIE measurement uses continuous time-stamping to observe slow phase shifts (wander) in nominally stable signals during extended periods of time.

16 FCA3000, FCA3100, and MCA3000 Series User Manual

Getting Acquainted with Your Instrument

Math/Limit Menu

The Math/Limit

menu provides settings for applying mathematical calculations to

a measurement and enabling the instrument to perform limit testing.

Table 3: The Math submenu

Item Description

Math

K, L, M

Use this menu to select one of ﬁve formulas to apply to the measurement result, or select Off to disable the math function. The available formulas are:

K*X + L K/X + L (K*X + L)/M (K/X + L)/ M X/M – 1

K, L, and M a current non-modiﬁed measurement result.

Constants in the formulas that you can set to any value.

re constants that you can set to any value. X stands for the

The Limit submenu lets you set limit testing conditions and limit violation behavior. (See page 71, Limit Testing.)

Table 4: The Limit submenu

Item Description

Limit Behavior

Limit Mode

Lower Limit

Upper Limit

Sets the action the instrument performs when a limit violation is detected, or disables the limit test mode.

Sets the limit test boundary type (Upper, Lower, or Range).

Sets the value of the lower limit boundary.

Sets the value of the upper limit boundary.

FCA3000, FCA3100, and MCA3000 Series User Manual 17

Getting Acquainted with Your Instrument

User Opt Menu

The User Opt men

u lets you set general instrument parameters.

Table 5: The User Opt menu

Item Description

Save/Recall Save or recall up to twenty instrument conﬁguration setups or eight

measurement data sets in nonvolatile memory. Submenu items are:

Setup:

Save Current Setup: Save the current instrument conﬁguration to a

speciﬁed memory.

Recall Setup: Load the current instrument conﬁguration from a selected memory slot into the instrument. Use the Default setup to load the factory default setup into the instrument.

Modify Labels: Edit the seven-character label associated with each memory slot. Unique labels make it easier for you to remember the purpose of the setup.

Setup Protect: Access to the ﬁrst ten memory positions is prohibited when Setup Protect is ON. Switching OFF Setup Protect releases all ten memory positions simultaneously.

Dataset: Save or recall a single statistics measurement (instrument in Hold mode, press Restart to acquire a single measurement). Up to eight data sets can be saved in nonvolatile memory, each containing up to 32000 samples. If the pending measurement has more than 32000 samples, only the last 32000 samples are saved. The instrument assigns a default label to each data set, which you can edit.

Save: Save the current statistical measurement to the selected memory location.

Recall: Loads and displays the selected data set.

Erase: Erases the selected data set.

Total Reset: Restores all factory settings and erases all user information

(setups and data sets).

Calibrate This menu entry is accessible only for factory calibration purposes and is

password-protected.

Interface Sets the active bus interface (GPIB or USB) and associated address

information.

Bus Type: Select GPIB or USB.

GPIB Mode: Select Native (the SCPI command set used in this mode fully

exploits all the features of this instrument series) or Compatible (The SCPI command set used in this mode is compatible with Agilent 53131/132/181).

GPIB Address: Enter the GPIB instrument number (0–30) for this instrument.

Test

Select and run speciﬁc power-on tests.

Test Mode: Select an individual instrument self-test, or select all tests.

Start Test: Runs the selected test.

18 FCA3000, FCA3100, and MCA3000 Series User Manual

Table 5: The User Opt menu (cont.)

Item Description

Digit B lanks

About

Sets the number of display digits to mask.

Jittery measurement results can be made easier to read by masking one or more of the least signiﬁcant digits. Use the Up or Down arrow keys to change the number, or enter the desired number (between 0 and 13) from the keypad. The blanked digits are marked by dashes on the screen.

Displays instrument information, including model, serial number, instrument ﬁrmware version, time base option and calibration date, and the channel C upper frequency limit (for instruments with Channel C option).

Getting Acquainted with Your Instrument

FCA3000, FCA3100, and MCA3000 Series User Manual 19

Getting Acquainted with Your Instrument

20 FCA3000, FCA3100, and MCA3000 Series User Manual

Input Signal Conditioning

The instrument provides input ampliﬁers to adapt the widely varying signals in the ambient world to the measuring logic of the instrument. These ampliﬁers have many con together and affect the signal.

trols, and it is essential to understand how these controls work

The followi technical diagram but is intended to help you understand the controls.

Push t

ng block diagram shows the input signal ﬂow path. It is not a complete

he Input A or Input B menu button to access the input signal controls.

Input Controls

can set the input impedance to 1 MΩ or 50 Ω in the corresponding Input A

Impedance

Attenuation

FCA3000, FCA3100, and MCA3000 Series User Manual 21

You or Input B menu.

CAUTION. Switching the impedance to 50 Ω when the input voltage is above

12 V

You can attenuate the input signal amplitude by 1 or 10 by toggling the menu softkey marked 1x/10x.

Use attenuation whenever the input signal exceeds the dynamic input voltage range ±5 V, or when attenuation can reduce the inﬂuence of noise and interference. (See page 26, How to Reduce or Ignore Noise and Interference.)

may cause permanent damage to the input circuitry.

RMS

Input Signal Conditioning

Coupling

Switch between

Use the AC coupling feature to eliminate unwanted DC signal components. Always use AC c oupling when the AC signal is superimposed on a DC voltage that is higher than the trigger level setting range. For example, when you measure symmetrical signals, such as sine and square/triangle waves, AC coupling ﬁlters out all DC around the middle of the signal where triggering is most stable.

Use DC co high duty cycle. The following ﬁgures show how pulses can be missed, or that triggering does not occur at all, because the signal amplitude drops below the trigger hysteresis band.

AC coupling and DC coupling by toggling the softkey AC/DC.

components. This means that a 0 V trigger level is always centered

upling for signals with a changing duty cycle or with a very low or

Signal Filters

22 FCA3000, FCA3100, and MCA3000 Series User Manual

If you cannot obtain a stable reading, the signal-to-noise ratio (often designated S/N or SNR) might be too low, probably less than 6 to 10 dB. Certain conditions call for special solutions like high-pass, bandpass or notch ﬁlters, but usually the unwanted noise signals have higher frequency than the signal you are interested

n. In that case you can utilize the built-in low-pass ﬁlters. There are both analog

i and digital ﬁlters, which you can couple together.

Figure 1: The menu choices after s electing FILTER.

Input Signal Conditioning

Analog Low-pass Filter. The instrument has analog RC low for Input A and B. The cutoff frequency is approximately 100 kHz, and the signal rejection is 20 dB at 1 MHz. Accurate frequency measurements of noisy low-frequency signals (up to 200 kHz) can be made when the noise components have signiﬁcantly higher frequencies than the fundamental signal.

Digital Low-pass Filter. The Digital LP ﬁlter utilizes the Hold-Off function. With trigger Hold-Off it is possible to insert a dead time in the input trigger circuit. This means that the input of the instrument ignores all hysteresis band crossings by the input signal during a preset time after the ﬁrst trigger event.

When you set the Hold-Off time to approximately 75% of the cycle time of the signal, erroneous triggering is inhibited around the point where the input signal returns through the hysteresis band. When the signal reaches the trigger point of the next cycle, the set Hold-Off time has elapsed and a new and correct trigger is initiated.

Instead of making you calculate a suitable Hold-Off time, the instrument will do the job for you by conver LP Freq menu to an equivalent Hold-Off time.

ting the ﬁlter cutoff frequency you enter in the Digital

-pass ﬁlters, one each

You should be aware of a few limitations with using effectively and unambiguously. First you must have a rough idea of the frequency to be measured. A cutoff frequency that is too low might give a perfectly stable reading that is too low. In such a case, triggering occurs only on every 2nd, 3rd, or 4th cycle. A cutoff frequency that is too high (>2 times the input frequency) also leads to a stable reading. Here one noise pulse is counted for each half-cycle.

The cutoff frequency setting range is very wide: 1 Hz – 50 MHz

Use an oscilloscope for veriﬁcation if you are in doubt about the frequency and waveform of your input signal.

FCA3000, FCA3100, and MCA3000 Series User Manual 23

the digital ﬁlter feature

Input Signal Conditioning

Figure 2: Digital LP ﬁlter operates in the measuring logic, not in the input ampliﬁer.

Trigger Mode (Man/Auto)

This menu item sets the trigger mode. When Auto is active the instrument automatically measures the peak-to-peak levels of the input signal and sets the

r level to 50% of that value. The attenuation is also set automatically.

trigge

For rise/fall time measurements the instrument sets the trigger levels to 10%

% of the measured peak values.

and 90

When Manual is active the trigger level is set in the Trig menu. The current

ger value is shown below the Trig menu item.

trig

Speeding up measurements. The Auto trigger function measures amplitude and calculates trigger level rapidly, but if you want faster measurement speed without sacriﬁcing the beneﬁts of automatic triggering, then use the Auto Trig Low Freq function to set the lower frequency limit for voltage measurement. This menu

em is found in Settings > Misc > Auto Trig Low Freq.

If you know that the signal you are interested in always has a frequency higher

an a certain value f

th The range for f

low

, then you can enter this value from a value input menu.

low

is 1 Hz to 100 kHz, and the default value is 100 Hz. The higher value, the faster the measurement speed due to more rapid trigger level voltage detection.

NOTE. You can use auto trigger on one input and manual trigger levels on the

other.

24 FCA3000, FCA3100, and MCA3000 Series User Manual

Input Signal Conditioning

Manual Trigger (Trig)

TheTrigmenule increment or decrement the trigger level value, or use the keypad to enter a speciﬁc value. Keep the arrow buttons depressed for faster response.

Setting manual trigger levels speeds up the measurement cycle. Manual triggers do not require the instrument to detect and calculate the trigger levels.

NOTE. The instrument switches from Auto to Man trigger m ode if you enter a

trigger level manually.

NOTE. You should not use a manual trigger to take measurements of signals

with unstable levels.

Convert

trigger levels into ﬁxed manual trigger levels by switching from Auto trigger mode to Manual trigger mode. The current calculated auto trigger level (shown under the Tr ig menu item) becomes the new ﬁxed manual level. Subsequent measurements are considerably faster because the instrument does not calculate the trigger levels for each measurement.

NOTE.

other.

ing an auto trigger level to manual. You can convert the calculated Auto

You can use auto trigger on one input and manual trigger levels on the

ts you enter a speciﬁc trigger value. Use the arrow buttons to

FCA3000, FCA3100, and MCA3000 Series User Manual 25

Input Signal Conditioning

How to Reduce o

r Ignore Noise and Interference

The instrument input circuits are sensitive to noise. Matching the input signal amplitude and noise characteristics to the instrument’s input sensitivity (trigger levels) redu an incorrect trigger level with a narrow hysteresis can cause incorrect counts on variable-level signals, as shown in the following ﬁgure.

ces the risk of wrong counts from noise and interference. For example,

A wider trigger hysteresis provides correct triggering and mesurements on variable-level and noisy signals.

Use the following functions to reduce or eliminate the effect of noise and improve measurement results:

10x input attenuator

Continuously variable trigger level (Auto trigger)

Continuously variable hysteresis for some functions

Analog low-pass noise suppression ﬁlter

Digital low-pass ﬁlter (Trigger Hold-Off)

26 FCA3000, FCA3100, and MCA3000 Series User Manual

Input Signal Conditioning

Trigger Hysteresis

You can use seve measurements possible on very noisy signals.

Optimizing th the trigger control, is independent of input frequency and useful over the entire frequency range. LP ﬁlters, on the other hand, function selectively over a limited frequency range.

The signal needs to cross the 20 mV input hysteresis band before triggering can even occur. This minimum trigger hysteresis prevents the input circuit from self-oscillating and reduces its sensitivity to noise. Other names for trigger hysteresis are trigger sensitivity and noise immunity.

Lower-level noise on a signal can also affect the trigger point by advancing or delaying it, even if the noise does not cause incorrect counts. This trigger uncertainty is of particular importance when measuring low frequency signals,

he signal slew rate (in V/s) is low for LF signals.

since t

ral of the above techniques simultaneously to make reliable

e input a mplitude and trigger level, and using the attenuator and

To reduce trigger uncertainty, the signal needs to cross the hysteresis band a s fast as possible (high slew rate). A high amplitude signal passes the trigger hysteresis band faster than a low amplitude signal. For low frequency measurements where the trigger uncertainty is of importance, do not attenuate the signal too much, and set a high instrument sensitivity level.

FCA3000, FCA3100, and MCA3000 Series User Manual 27

Input Signal Conditioning

Wrong counts caused by trigger errors are much more common. To avoid incorrect counting caused by spurious signals, reduce input signal amplitudes. This is particularly true when measuring on high impedance circuitry and when using 1MΩ input impedance. Under these conditions, the cables easily pick up noise.

External attenuation and the internal 10x attenuator reduce the signal amplitude, including the noise, while the internal sensitivity control in the instrument reduces the instrument’s sensitivity, including sensitivity to noise. To reduce excessive signal amplitudes, use the built-in 10x attenuator, an external coaxial attenuator, or a 10x probe.

How To Use Trigger Level

Settings

For most frequency measurements, the optimal triggering is obtained by positioning the mean trigger level at mid amplitude, using wide hysteresis band, depending on the signal characteristics.

When measuring low-noise LF sine wave signals, use a hi hysteresis band) to reduce the trigger uncertainty. Triggering at or close to the middle of the signal leads to the smallest trigger (timing) error since the signal slope is steepest at the sine wave center.

When you have to avoid wrong counts due to noisy signals, expanding the hysteresis window gives the b middle of the input signal. The signal excursions beyond the hysteresis band should be equal.

Auto trigger. For normal frequency measurements, that is without arming, the Auto Trigger function changes to Auto (Wide) Hysteresis, which widens the hysteresis window to between 70% and 30% of the peak-to-peak amplitude.

est result if you still center the window around the

either a narrow or a

gh sensitivity (narrow

28 FCA3000, FCA3100, and MCA3000 Series User Manual

Input Signal Conditioning

This is done wit minimum and maximum trigger levels (the levels where triggering just stops). The instrument then sets the hysteresis levels to the calculated values. The default relative hysteresis levels are indicated by 70% on Input A and 30 % on Input B. These values can be manually adjusted between 50% and 100% on Input A and between 0% and 50% on Input B. The signal, however, is only applied to one channel.

The instrument normally repeats the signal trigger level detection process for each frequ prerequisite to enable Auto triggering is therefore that the input signal is repetitive. Another condition is that the signal amplitude does not change signiﬁcantly after the measurement has started.

Auto trigger also reduces the maximum measuring rate when an automa tic test system makes ma ny measurements per second. To increase the measuring rate, push the Auto Set button once to set the trigger level manually based on the values calculated by the Auto level mode.

Manual trigger. Switching to Man Trig also means Narrow Hysteresis at the last Auto level. Pushing Auto Set once starts a single automatic trigger level calculation (Auto Once). This calculated value, 50% of the peak-to-peak amplitude, is the new ﬁxed trigger level, from which you can make manual adjustments if required.

h a successive approximation method to determine the signal

ency measurement to identify new trigger and hysteresis values. A

Harmonic distortion. As rule of thumb, stable readings are free from noise or interference. However, stable readings are not necessarily correct; harmonic distortion can cause incorrect yet stable readings.

Sine wave signals that contain harmonic distortion, such as those in the following graphics, can be measured by setting correct trigger levels (Manual mode) or by using continuously variable sensitivity (Auto mode). You can also use Trigger Hold-Off to position the trigger point to a speciﬁed point on the signal and

mprove results.

FCA3000, FCA3100, and MCA3000 Series User Manual 29

Input Signal Conditioning

30 FCA3000, FCA3100, and MCA3000 Series User Manual

Frequency Measurements

Theory of Measurement

Reciprocal Counting

The FCA3000, FCA3100, and MCA3000 Series instruments use a high-resolution reciprocal counting technique that synchronizes the m easurement start with the input signal. This results in an exact number of integral input cycles to count.

Reciprocal counting is a signiﬁcant improvement over simple frequency counters that count the number of input cycles during a preset, nonsynchronized gate time. Simple gated counting can result in a ±1 input cycle count error, especially for low-freq

After the start of the set measurement time, the instrument synchronizes the beginnin

In the same way, the instrument synchronizes the stop of the actual gate time with the input sign counting technique allows you to simultaneously measure the actual gate time (tg) and the number of cycles (n) tha t occurred during this gate time.

uency measurements.

g of the actual gate time with the ﬁrst trigger event (t

al, after the set measurement time has elapsed. The multi-register

) of the input signal.

Thereafter, the instrument calculates the frequency according to:

The instrument measures the gate time, tg, with a resolution of 100 ps, independent of the measured frequency. So the use of prescalers quantization error. Therefore, the relative quantization error is 100 ps/tg.

For a 1-second measurement time, this value is:

Except for very low frequencies, tgand the set measurement time are nearly identical.

Sample-Hold

FCA3000, FCA3100, and MCA3000 Series User Manual 31

If the input signal disappears during the measurement, the instrument will behave like a voltmeter with a sample-and-hold feature and will freeze the result of the previous measurement.

does not inﬂuence the

Frequency Measurements

Time-Out

Measuring Speed

Mainly for GPIB reached by pressing Settings > Misc > Timeout. The range of the ﬁxed time-out is 10 ms to 1000 s, and the default setting is Off.

Select a time that is longer than the c ycle time of the lowest frequency you are going to measure; multiply the time by t he prescaling factor of the input channel and enter that time as time-out.

When no triggering has occurred during the time-out, the instrument will show NO SIGNAL.

The set measurement time determines the measuring speed for the Period Average and Frequency measurements. For continuous signals:

when Auto trigger is on and can be increased to:

when Manual trigger is on, or using GPIB:

use, you can manually select a ﬁxed time-out in the menu

Average and single cycle measurements. To reduce the actual gate time or measuring aperture, the counters have very short measurement times and a mode called Single for period measurements. The latter means that the instrument measures during only one cycle of the input signal. In applications where the instrument uses an input channel with a prescaler, the Single measurement will last as many cycles as the division factor. If you want to measure with a very short aperture, use an input with a low division factor.

Averaging is the normal mode for frequency and p eriod measurements when you want to reach maximum resolution. There is always a tradeoff between time and precision, however, so decide how many digits you need and use as short a measurement time as possible to arrive at your objective.

Prescaling may inﬂuence measurement time (FCA3003, FCA3020, FCA3103, FCA3120). Prescalers do affect the minimum measurement time, because short

bursts have to contain a minimum number of carrier wave periods. This number depends on the prescaling factor.

32 FCA3000, FCA3100, and MCA3000 Series User Manual

Frequency Measurements

Figure 3: Divide-by-16 prescaler.

The ﬁgure shows the effect of the 3 GHz prescaler. For 16 input cycles, the prescaler gives one square wave output cycle. When the instrument uses a prescaler, it counts the number of prescaled output cycles, such as f/16. The display s

hows the correct input frequency since the instrument compensates for

the effect of the division factor d as follows:

Prescalers do not reduce resolution in reciprocal counters. The relative quantization error is still:

Use the following table to ﬁnd the prescaling factors used in different measurement modes:

Table 6: Measurement prescaling factors

Function Prescaling factor

Freq A/B (300 MHz)

Burst A/B (<160 MHz)

Burst A/B (>160 MHz)

Period A/B AVG (400 MHz)

Period A/B SGL (300 MHz)

Freq C (3 GHz)

Freq C (20 GHz)

128

LF signals. Signals below 100 Hz should be measured with manual triggering unless the default setting (100 Hz) is changed. (See page 16.) The low limit can be set to 1 Hz, but the measurement process is slowed down considerably if auto triggering is used with very low frequencies.

FCA3000, FCA3100, and MCA3000 Series User Manual 33

Frequency Measurements

When measuring a nonprescaled measurement like Period Sgl, t he measurement requires at least the duration of one cycle, that is 10 seconds, and at worst nearly 20 seconds. The worst case is when a trigger event took place just before the beginning of a measurement time, as shown in the following ﬁgure. Measuring the frequency of the same signal will take twice as long, since this function i nvolves prescaling by afactoroft instrument will require 20 – 40 seconds to take the measurement.

pulses with a low repetition rate, such as a 0.1 Hz pulse w ith

wo. Even if you enter a short m easurement time for this example, the

RF signals (FCA3003, FCA3020, FCA3103, FCA3120). The C-input prescaler divides the input frequency before it is counted by the normal digital counting logic. The division factor is called prescaler factor and can have different values depending on the prescaler type. The 3 GHz prescaler is designed for a prescaling factor of 16. This means that an input C frequency of, for example, 1.024 GHz is transformed to 64 MHz.

Prescalers are designed for optimum performance when measuring stable continuous RF. Most prescalers are inhe rently unstable and would self-oscillate without an input signal. To prevent a prescaler from oscillating, a “Go-detector” is incorporated. The Go-detector continuously measures the level of the input signal and blocks the prescaler output when no signal, or a signal that present.

Figure 4: Go-detector in the prescaler.

is too weak, is

34 FCA3000, FCA3100, and MCA3000 Series User Manual

Frequency Measurements

The presence of the signal itself. Regardless of the instrument’s ability to measure during very short measurement times, the burst duration must meet the following minimum conditions:

Normally the real minimum limit is set by other factors, like the speed of the Go-detector. This speed depends on the speciﬁc input option used.

Measuring microwaves (FCA3020, FCA3120, MCA3027, and MCA3040). Measuring frequencies up to 20 GHz is possible on the FCA3020 and FCA3120 instruments, which inc

The MCA3027 and MCA3040 let you measure frequencies up to 27 GHz and 40 GHz, r input signal with a known local oscillator (LO) frequency until there is a signal present within the passband of the IF ampliﬁer (in this case 10 – 200 MHz). (See Figure 5.)

lude 20 GHz prescalers.

espectively, using down converters. Down converters m ix the unknown

a burst signal to be measured makes certain demands upon

Figure 5: Microwave acquisition in the MCA3000 Series.

The basic LO frequency range is 430 – 550 MHz and is divided into several discrete frequencies fetched from a look-up table. The LO output is fed to a comb generator that creates a harmonic spectrum covering the whole speciﬁed microwave range .

The automatic process of calculating the input frequency consists of the following steps:

FCA3000, FCA3100, and MCA3000 Series User Manual 35

Frequency Measurements

1. Preacquisitio

at the input and determines the LO frequency that will provide an IF signal above a certain threshold level. This is done by sequentially stepping the LO from the highest value in the look-up table to the lowest value and applying the resulting comb generator spectrum to the mixer. The process is stopped when the signal detector o utputs a status signal to the processor.

2. Acquisition: This process determines the harmonic needed to generate the

IF signal. The instrument measures the IF, decreases the LO frequency by 1MHz,andm difference between the two measurements, the instrument can determine if the original IF should be added to or subtracted from the calculated harmonic to arrive at the ﬁnal value. For example, if the difference between the two values is 5 MHz, then the instrument knows that the ﬁfthharmonicistheorigin.

3. Final RF calculation: The instrument knows the LO frequency, the

multiplication factor n and the sign. The instrument counts the IF during a measurement time corres ponding to the desired resolution and uses the result

ulate the ﬁnal value to display as:

to calc

There are several conditions that can complicate the acquisition process. All of them are handled by measures taken by the instrument ﬁrmware. For example:

n: This process detects if there is a measurable signal present

easures the IF again. By examining the value and sign of the

Input A, B

One of the step frequencies produces an IF but not its shifted value. The instrument goes to the next table value.

Frequency modulation causes an unstable ‘n’ value calculation. The instrument increases the measuring time.

Power measurement. The MCA3027 and MCA3040 instruments can measure microwave signal power over the entire range of the Input C down-converter. Frequency-dependent power measurement correction data stored in the down converter help improve measurement readings.

Menu path: Meas > Freq.

Frequency is measured as the inverse of the time between one trigger point and the next within the hysteresis band. The instrument measures frequencies on Input A and B from 0.001 Hz and 300 MHz in auto trigger mode (0.001 Hz to 400 MHz in manual trigger mode).

36 FCA3000, FCA3100, and MCA3000 Series User Manual

Frequency Measurements

Frequencies above 100 Hz are best measured using the Default Setup.(See page 85, Def Other important automatic settings are AC Coupling, Auto Trig and Meas Time 200 ms. The default settings provide a successful starting point for frequency measurements.

ault Instrument Settings.) Then Freq A is selected automatically.

The following is a list of settings to use for optimum frequency measurements:

AC Coupling, because possible DC offset is normally undesirable.

rig means Auto Hysteresis in this case, (comparable to AGC) because

Auto T

superimposed noise exceeding the normal narrow hysteresis window is suppressed.

Meas Time 200 ms to get a reasonable trade off between measurement speed and resolution.

Some of the settings made above by recalling the Default Setup canalsobemade by activating the Auto Set button. Pushing it once means:

Auto Trig. Note that this setting is made once only if Man Trig was selected earlier.

Pushing Auto Set twice within two seconds also sets the measurement time to 200 ms.

FCA3000, FCA3100, and MCA3000 Series User Manual 37

Frequency Measurements

Input C

FCA3X00 Series

Instruments

MCA3000 Seri

Instruments

The Input C prescaler in applicable FCA3X00 Series instruments lets you measure up to 20 GHz. The Input C prescaler is fully automatic and no setup is required.

The MCA3000 Series instruments measure RF frequencies up to 27 GHz or

40 GHz by means of an automatic down-conversion technique. (See page 35, Measuring microwaves (FCA3020, FCA3120, MCA3027, and MCA3040).) Faster (manual) a frequency. Enter the frequency as a starting point for the acquisition process.

An additi

RatioA/B,B/A,C/A,C/B

Menu pat

To ﬁnd the ratio between two input frequencies, the instrument counts the cycles on two c the result on the secondary channel. Ratio can be measured between Input A and Input B, where either channel can be the primary or the secondary channel. Ratio can also be measured between Input C and Input A or between Input C and Input B, where Input C is the primary channel.

cquisition is an alternative if you know the approximate measured

onal feature is measuring signal power with high resolution.

h: Meas > Freq Ratio.

hannels simultaneously and divides the result on the primary channel by

Burs

tA,B,C

Menu path: Meas > Freq Burst.

A burst signal has a carrier wave (CW) frequency and a modulation frequency, also called the pulse repetition frequency (PRF), that switches the CW signal on and off.

Both the CW frequency, the PRF, and the number of cycles in a burst are measured without external arming signals and with or without selectable start arming delay. (See page 73, Arming.)

38 FCA3000, FCA3100, and MCA3000 Series User Manual

Frequency Measurements

Burst and Triggering

The general fre to burst measurements. The minimum number of cycles in a burst on Input A or Input B is 3 below 160 MHz and 6 between 160 MHz and 400 MHz. Burst measurements on Input C involve prescaling, so the minimum number of cycles is 3 x prescaling factor. For example, the 3 GHz model has a prescaling factor of 16 and therefore requires at least 48 cycles in each burst.

The minimum burst duration is 40 ns below and 80 ns above 160 MHz.

Bursts with a PRF above 50 Hz can be measured with auto triggering on.

Out-of-sync errors may occur more frequently when using Auto trigger. (See page 41, Possible burst measurement errors.)

When PRF is below 50 Hz and when the gap between the bursts is very small, use manual triggering.

Always try using Auto Set ﬁrst. The Auto Trigger and the Auto Sync functions in combination will give satisfactory results in most cases. Sometimes switching from Auto to Manual triggering in the Input A/B menus can produce more stable readings.

Input C has always automatic triggering and Auto Set only affects the burst synchronization.

quency limitations for the respective measuring channel also apply

Burst Measurements Using

Manual Presetting

Threetimevaluesmustbesettomeasurethecorrectpartofaburst;Measure Time,SyncDelay,andArmStartDelay.

Figure 6: Three time values must be set to measure the correct part of a burst

The internally synchroniz ed BURST function lets you measure frequencies on Input A and B from 0.001 Hz and 300 MHz in auto trigger mode (0.001 Hz to 400 MHz in manual trigger mode), and on Input C with limited speciﬁcations to the upper frequency limit of the prescaler. To take a burst measurement using manual settings:

FCA3000, FCA3100, and MCA3000 Series User Manual 39

Frequency Measurements

1. Push Meas > Freq

2. Select the input source A, B,orC.

3. Push Settings > Burst.

4. Push Meas Time and enter a measurement time value that is shorter than the

burst duration minus two CW cycles. If you do not know the approximate burst parameters of your signal, always start with a short measurement time and increas

5. Push Sync Delay and enter a value longer than the burst duration and shorter

than the in

6. Push Start Delay and enter a value longer than the transient part of the burst

pulse.

7. Select Frequency Limit (160/300 MHz) if Input A or Input B is to be used.

Use the low limit if possible to minimize the number of cycles necessary to make a measurement.

e it gradually until the readout gets unstable.

verse of the PRF.

>FreqBurst.

8. Push Save|Exit to display the measurement.

The instrument displays all relevant burst measurements.

Selecting measurement time. The measurement time must be shorter than the duration of the burst. If the measurement continues during part of the burst

p, no matter how small a period of time, then the measurement is ruined.

ga Choosing a measurement time that is too short is better since it only reduces the resolution. Making burst frequency measurements on short bursts means using short measurement times, giving a poorer resolution than normally achieved with the instrument.

How sync delay works. The sync delay works as an internal start arming delay; it prevents the start of a new measurement until the speciﬁed sync delay time has expired.

40 FCA3000, FCA3100, and MCA3000 Series User Manual

Frequency Measurements

After the set measurement time has started, the instrument synchronizes the start of the measurement with the second trigger event in the burst. This means that the measurement does not start erroneously during the Burst Off duration or while inside the burst.

Possible burst measurement errors. Before the measurement is synchronized with the burst signal, the ﬁrst measurement(s) could start accidentally during the presence of a burst. If this would happen and if the remaining burst duration is shorter than the set measurement time, the readout of the ﬁrst measurement will be wrong. However, after this ﬁrst measurement, a properly set start-arming sync

time will synchronize the next measurements.

delay

In manually operated applications, this is not a problem. In automated test systems

e the result of a single measurement sample must be reliable, at least two

wher measurements must be made, the ﬁrst to synchronize the measurement, and the second from which the measurement result can be read out.

Frequency Modulated Signals

A frequency modulated signal is a carrier wave signal (CW frequency = f0)that changes in frequency to values higher and lower than the frequency f modulation signal that changes the frequency of the carrier wave.

The instrument can measure:

= Carrier frequency (Frequency).

= Maximum frequency (MAX).

max

= Minimum frequency (MIN).

min

Δf = Frequency swing = f

max–f0

(P-P).

.Itisthe

FCA3000, FCA3100, and MCA3000 Series User Manual 41

Frequency Measurements

Frequency f

To d etermine th

approximation of f

1. Push Analyze t

e carrier wave frequency, measure f

o get an overview of all the statistical parameters.

which is a close

mean

2. Select the measurement time so that the instrument measures an even number

of modulati

on periods. This way the positive frequency deviations will

compensate the negative d eviations during the measurement.

For example

, if the modulation frequency is 50 Hz and the measurement time

200 ms, the instrument takes 10 complete modulation cycle measurements.

If the modu

lation is non-continuous, like a voice signal, it is not possible to fully compensate positive deviations with negative deviations. In this case, part of a modulation swing may remain uncompensated for, and result in a measurement that is too high or too low.

Figure 7: Frequency modulation

In the worst case, exactly half a modulation cycle would be uncompensated for, giving a maximum uncertainty of:

For very accurate measurements of the carrier wave frequency f0, measure on the unmodulated signal if it is accessible.

42 FCA3000, FCA3100, and MCA3000 Series User Manual

Frequency Measurements

Modulation fre

quencies above 1 kHz.

1. Turn off Single.

2. Set a long measurement time that is an even multiple of the inverse of the

modulation frequency. You will get a good approximation when you select a long measurement time, for instance 10 s, and when the modulation frequency is high, abo

ve 1000 Hz.

Low modulation frequencies.

1. Push Setti

ngs > Stat and set the No. of samples parameter to as large a value

as possible considering the maximum allowed measurement time.

2. Push Anal

yze and let the instrument calculate the mean value of the samples.

You will usually get good results with 0.1 s measurement time per sample and more tha size and measurement time for speciﬁc cases. It depends on the actual f

Here th

n30samples(n≥30). You can try out the optimal combination of sample

and Δf

e sampling frequency of the measurement (1/measurement time) is asynchronous with the modulation frequency. This leads to individual measurement results which are randomly higher and lower than f statistically averaged value of the frequency f

approaches f0when the number

mean

.The

of averaged samples is sufﬁciently large.

max

fmax (MAX)

fmin (MIN)

When the instrument measures instantaneous frequency values (when you select a very short measurement time), the RMS measurement uncertainty of the measured value of f

here n is the number of averaged samples of f.

is:

To m e a s u r e fmax:

1. Push Settings > Stat and set No.of samples to 1000 o r more.

2. Push Meas Time and select a low value.

3. Push Analyze; the instrument displays f

in the MAX readout.

max

1. Push Settings > STAT and set No.of samples to 1000 or more.

2. Push Meas Time and select a low value.

3. Push Analyze; the instrument displays f

in the MIN readout.

min

FCA3000, FCA3100, and MCA3000 Series User Manual 43

Frequency Measurements

Δ f

p-p

(P-P)

1. Push Settings >

Stat and set No.of samples to 1000 or more.

2. Push Meas Time and select a low value.

3. Push Analyze and read P-P.

Errors in f

max,fmin

,andΔf

p-p

A measurement time corresponding to 1/10 cycle, or 36° of the modulation signal, leads to an error of approximately 1.5%.

Select the measurement time such that:

AM Signals

Measuring the Carrier

Wave Frequency

Figure 8: Error when determining fmax

To be conﬁdent that the captured maximal frequency really is f

, select a

max

sufﬁciently large number of s amples, such as n ≥1000.

The instrument can usually measure both the carrier wave frequency and modulation frequency of AM signals. These measurements are much like the burst measurements described earlier in this manual.

The carrier wave (CW) is only continuously present in a narrow amplitude band in the middle of the signal if the modulation depth is high. If the trigger sensitivity (hysteresis) of the instrument is too wide, triggering will miss some cycles and the measurement results will be incorrect.

44 FCA3000, FCA3100, and MCA3000 Series User Manual

To measure the CW frequency:

1. Push the Input A menu button.

Frequency Measurements

Measuring the Modulating

Frequency

2. Select a

measurement time that gives you the resolution you want.

3. Enable Manual trigger.

4. Push Trig level and enter 0Vtrigger level and Save|Exit).

5. Select AC coupling.

6. Select 1x attenuation to get a narrow hysteresis band. If the instrument

triggers on noise, widen the hysteresis b and with the ‘variable hysteresis’ function, that is enter a trigger level >0 V but < V

P-Pmin

The easiest way to measure the modulating frequency is after demodulation, for instance by using an RF-detector probe (also known as a demodulator probe) with AC coupling on the input channel.

If no suitable demodulator is available, use the Freq Burst functiontomeasure the modulation frequency in the same way as when measuring Burst PRF.

To measure the modulating frequency:

1. Push Meas > Freq Burst A.

2. Push Settings > Burst > Meas Time and enter a mea surement time that is

approximately 25% of the modulating period.

3. Push Sync Delay and enter a value that is approximately 75% of the

modulating period.

4. Push Input A andturnonManual trigger.

FCA3000, FCA3100, and MCA3000 Series User Manual 45

Frequency Measurements

Period

Single A, B and Avg. A, B,

5. Push Trig and en to the following ﬁ gure.

The PRF readout shows the modulating frequency even though the main frequenc

Menu pa

From a measuring point of view, the period function is identical to the frequency funct the frequency 1/f.

y reading may be unstable.

th: Meas > Period > Single.

ion. This is because the period of a cyclic signal has the reciprocal value of

ter a trigger level that makes the instrument trigger according

Single A, B Back-to-Back

(FCA3100 Series Only)

actice there are two minor differences.

In pr

1. The instrument calculates frequency (always average) as:

number of cycles

actual gate time

while it calculates period averages as:

actual gate time

number of cycles

2. The instrument does not use a prescaler for Single Period measurements.

All other functions and features as described earlier for Frequency measurements applytoPeriodmeasurements.

Menu path: Meas > Period > Single Back to Back.

This measurement takes consecutive period measurements without dead time by using time-stamping.

46 FCA3000, FCA3100, and MCA3000 Series User Manual

Frequency Measurements

Average A, B

Every positive the maximum frequency (125 kHz with interpolator calibration On or 250 kHz with interpolator calibration Off) is time-stamped. For every new time stamp the previous value is subtracted from the current value and displayed.

In Val ue mode the display is updated every new period if the period time exceeds 200 ms. For shorter times, every second, third, fourth, and so on result is displayed due to the limited updating rate.

In Analyze mode the graphs and statistical data contain all periods up to the maximum input frequency. For higher frequencies the instrument displays the average period time during the 4 µs or 8 µs observation. So, for higher frequencies the actua

Themainpurposeofthisfunctionistomakecontinuousmeasurementsof

ely long period times without losing single periods due to result processing.

relativ A typical example is the 1 pps time base output from GPS receivers.

Menu path: Meas > Period > Average.

The instrument measures the average period of the signal. This measurement provides a higher resolution readout than the Single Period measurement.

or negative zero crossing (depending on the selected slope) up to

l function is Period Average Back-to-Back.

Frequency

Freq A, B Back-to-Back

3100 Series Only)

(FCA

Menu path: Meas > Freq > Single Back to Back.

This measurement uses time stamping to take consecutive frequency measurements without dead time.

This is the inverse function of Period Back-to-Back. In Analyze mode, measurement time is used for pacing the time stamps. The pacing parameter is

ot used in this case.

Consecutive frequency average measurements without dead time are used to

alculate Allan deviation. Such statistical measures are widely used by oscillator

c manufacturers to describe short-term stability.

FCA3000, FCA3100, and MCA3000 Series User Manual 47

Time Measurements

Introduction

Measuring the time between a start and a stop condition on two separate channels is the basis for all time interval measurements. In addition to Time Interval A to B,thecou like Pulse Width and Rise/Fall Time.

nters also offer other channel combinations and derived functions

Triggering and Time

urements

Meas

Time is mea measurements are possible only if the hysteresis band is narrow.

The set trigger level and trigger slope deﬁne the start and stop triggering. If Auto

n, the instrument sets the trigger level to 50% of the signal amplitude, which

is o is ideal for most time measurements.

sured between the trigger point and the reset point. Accurate

Summary of conditions for reliable time measurements.

Auto Once, or setting the trigger levels determined by Auto Trig, is normally the best choice when making time measurements. Push Man Trig and push

Auto Set once.

DC coupling.

1x Attenuation. Selected automatically if Auto Set was used before to set

the trigger levels.

High signal level.

Steep signal edges.

48 FCA3000, FCA3100, and MCA3000 Series User Manual

Time Measurements

Time Interval

Even though the ﬁnite value that would introduce a small timing error for signals with different rise and fall times, for instance asymmetrical pulse signals like those in the previous ﬁgure. This timing error is taken care of by using hysteresis compensation that virtually moves the trigger points by half the hysteresis band.

Menu path: Meas > Time > Time Interval.

The Time Interval measurements let you measure rise and fall times betwee n speciﬁed trigger levels.

Use the Input A/B > Slope button (marked with a positive slope edge or negative slope edge symbol) to set the signal edge on which to start or stop the measurement.

Time Interval A to B: The instrument measures the time between a start condition on Input A and a stop condition on Input B.

Time Interval B to A: The instrument measures the time between a start condition on Input B and a stop condition on Input A.

Time Interval A to A, B to B: When the same (common) signal source supplies both start and stop trigger events, connect the signal to either Input A or Input B.

input ampliﬁers have high sensitivity, the hysteresis band has a

Rise/Fall Time A/B

Menu path: Meas > Time > Rise Time, Meas > Time > Fall Time.

By convention, rise/fall time measurements are taken from when the signal passes 10% of its amplitude to when it passes 90% of its amplitude.

The instrument calculates and sets the trigger levels. Ris measured on both Input A and Input B.

Other parameters also measured are Slew Rate (V/s), V

For ECL circuits, the reference levels are 20% (start) and 80% (stop). In this case you can use either of two methods to set the reference values:

e and fall time can be

max

and V

min

FCA3000, FCA3100, and MCA3000 Series User Manual 49

Time Measurements

1. Select the gene

ral Time Interval function described above and set the trigger levels manually after calculating them from the absolute peak values. Then you can beneﬁt from the auxiliary parameters V

max

and V

.For

min

measurements made on Input A, use the following settings:

Rise Time:

Trig Level A = V

Trig Level B

min

+0.8 (V

min

+0.2 (V

max–Vmin

)

Fall Time:

Trig Level A = V

Trig Level B = V

min

+0.2 (V

min

+0.8 (V

max–Vmin

)

2. Select one of the dedicated Rise/Fall Time measurements and manually adjust the relative trigger levels (in %) when Auto Trigger is active. Use both input channel menus to enter the trigger levels, even though only one channel is the active signal input.

Overshoot or ringing can also affect your measurement. (See page 53, Auto Trigger.)

Time Interval Error (TIE) (FCA3100 Series Only)

Menu path: Meas > Time > TIE.

TIE measurement uses continuous time-stamping to observe slow phase shifts (wander) in nominally stable signals during extended periods of time. Monitoring

tributed PLL clocks in synchronous data transmission systems is a typical

dis application.

E measurements are only applicable to clock signals, not data signals.

The frequency of the signal to be checked can be either manually or automatically

et. Auto detects the frequency from the ﬁrst two samples. The value is rounded

s to four digits, for example 2.048 MHz and is output on the bus when a query is sent. It is also displayed as an auxiliary measurement in Va lue mode.

TIE is measured as the time interval between the input signal and the internal or external timebase clock. These signals are not phase-locked, so i rrespective of the real time interval value at the start of a measurement, the result at t = 0 is mathematically nulled. The graphic representation in Analyze mode starts at the coordinate origin.

50 FCA3000, FCA3100, and MCA3000 Series User Manual

Time Measurements

Pulse Width A/

Duty Fac

tor A/B

Menu path: Meas>Pulse>WidthPositive, Meas > Pulse > Width Negative.

Either Input A or Input B can be used for measuring, and both positive and negative pulse width can be selected.

Positive pulse width means the time between a rising edge and the next falling edge.

Negative pulse width means the time between a falling edge and the next rising edge.

The selected trigger slope is the start trigger slope. The instrument automatically selects the inverse polarity as the stop slope.

Menu path: Meas > Pulse > Duty Factor Positive, Meas > Pulse > Duty Factor Negative.

Duty factor (or duty cycle) is the ratio between pulse width and period time:

The instrument determines this ratio in one pass by taking three time stamp measurements (two consecutive positive trig-A and one negative trig-A, if the selected measurement function is Duty Factor Positive on Input A).

You can use either Input A or Input B for taking measurements, for both positive and negative duty factors. The instrument also displays Period and Pulse Width measurements.

NOTE. The total measurement time is tripled compared to a single measurement

because the measurement requires three measurement steps.

FCA3000, FCA3100, and MCA3000 Series User Manual 51

Time Measurements

Time Measurement Errors

Hysteresis

The trigger hysteresis can cause time measuring errors. Timing measurement triggers occur when the input signal crosses the entire hysteresis band, not when the input signal crosses at 50 percent of the amplitude, as shown in the following ﬁgure:

The hysteresis band is about 20 mV at 1x attenuation, and 200 mV at 10x attenuation.

To keep hysteresis trigger error low, set the attenuator to 1x when possible. Use 10x attenuation o nly when input signals have excessively large amplitudes, or when you need to set trigger levels higher than 5 V.

Overdrive and Pulse

Rounding

Additional timing errors can be caused by triggering with insufﬁcient signal overdrive. When triggering occurs too close to the maximum voltage of a pulse, two phenomena may inﬂuence your measurement uncertainty: overdrive and rounding.

Overdrive. When the input signal crosses the hysteresis band with only a marginal overdrive, triggering may take some 100 ps longer than usual. The speciﬁed worst case 500 ps systematic trigger error includes this error. To avoid this error, make sure that the input signal or trigger level has adequate overdrive.

Pulse rounding. Very fast pulses may suffer from pulse rounding, overshoot, or other aberrations. Pulse rounding can cause signiﬁcant trigger errors, p articularly when measuring on fast circuitry.

52 FCA3000, FCA3100, and MCA3000 Series User Manual

Time Measurements

Auto Trigger

Auto trigger is and ringing can cause Auto trigger to choose slightly wrong minimum and maximum signal levels. This does not affect measurements like frequency, but transition time measurements may be affected. Therefore, when working with known signals such as logic circuitry, set the trigger levels manually.

Always use manual trigger levels if the signal repetition rate drops below 100 Hz (default), or below the low frequency limit set by entering a value between 1 Hz and 50 kHz in the Auto trigger low frequency menu Settings > Misc > Auto

Trig Low Fr

very effective for measuring unknown signals. However, overshoot

eq.

FCA3000, FCA3100, and MCA3000 Series User Manual 53

Phase Measurements

Phase is the time difference between two signals of the same frequency, expressed as an angle.

The traditional method to measure phase delay with a timer/instrument is a two-step process consisting of two consecutive measurements; a period measurement followed immediately by a time interval measurement. The phase delay is then mathematically calculated as:

or in other words:

Phase A–B = 360° × Time Delay × Freq

The FCA3000, FCA3100, and MCA3000 Series instruments use a more elaborate method to determine phase. Both measurements are taken in one pass along with the measurement time stamp. Two consecutive time-stamps from trigger events on Input A and Input B are enough to calculate the phase difference, including the phase relationship of the signals.

54 FCA3000, FCA3100, and MCA3000 Series User Manual

Resolution

Possible Errors

Phase Measurements

You can take phase measurements on signals up to 160 MHz. The measurement resolution depends on the frequency. For frequencies below 100 kHz the resolution is 0.001°; for frequencies above 10 MHz it is 1°. Phase measurement resolution can be further improved by using the built-in statistics functions to average the

measurement.

Inaccuracies

Phase can b these very high frequencies the phase resolution is reduced to:

100 ps ×36

The inaccuracy of Phase A-B measurements depends on several external parameters:

Input signal frequency

Peak amplitude and slew rate for input signals A and B

Input signal S/N-ratio

Some internal instrument parameters are also important:

Inte

Variations in the hysteresis window between Input A and B

There are two types of phase measurement inaccuracy errors: random errors and systematic errors. The random errors consist of resolution (quantization) and

ise trigger error. Systematic errors consist of “inter-channel delay difference”

no and “trigger level timing” errors. Systematic errors are constant for a given set of input signals, and in general, you can compensate for them in the controller (GPIB-systems) or locally using the Math/Limit menu (manual operation) after making calibration measurements. (See page 58, Methods of compensation.)

e measured on input signal frequencies up to 160 MHz. However, at

0° × FREQ

rnal time delay between Input A and B signal paths

Random errors in phase measurements. The phase quantization error algorithm is:

100 ps ×360° × FREQ

For example, the quantization error for a 1 MHz input signal is:

100 ps ×360° × (1 × 10

The trigger noise error consists of start and stop trigger errors that should be added. For sinusoidal input signals each error is:

FCA3000, FCA3100, and MCA3000 Series User Manual 55

) ≈ 0.04°

Phase Measurements

Use the example

above and add some noise so that the S/N ratio is 40 dB. This corresponds to an amplitude ratio of 100 times (and power ratio of 10000 times). Then the trigger noise will contribute to the random error with:

The sum of random errors should not be added linearly

, but in an “RMS way”,

because of their random nature. Do this for the examples above:

Random error

The total random errors are thus:

What about random errors caused by internal ampliﬁer noise? Internal noise contribution is normally negligible. The phase error caused by noise on the signal, whether internal or external, is:

For an input signal of 250 mV

and the typical internal noise ﬁgure of 250 μV

rms

gives us a S/N-ratio of at least 60 dB (1000 times). This gives us a worst case error of 0.06°. Increasing the input signal to 1.5 V

decreases the error to 0.01°.

rms

Another way to decrease random errors is to use the statistics features of the instrument and calculate the mean value from several samples.

Systematic errors in phase measurements. Systematic errors consist of the following elements:

Inter-channel propagation delay difference.

Trigger level timing errors (start and stop), due to trigger level uncertainty.

The inter-channel propagation delay difference is typically 500 ps at identical trigger conditions in both input channels. Therefore, the corresponding phase difference is:

<0.5 ns × 360° × FREQ

The following table lists the phase differences caused by inter-channel propagation delay differences, by frequency:

Frequency Phase error in degrees

160 MHz

100 MHz

10 MHz

1MHz

100 kHz

10 kHz and below

28.8°

18.0°

1.8°

0.18°

0.018°

0.002°

56 FCA3000, FCA3100, and MCA3000 Series User Manual

Phase Measurements

The trigger lev

el timing error depends on the following factors:

The actual trigger point is not exactly zero, due to trigger level DAC uncertainty and comparator offset error.

The two signals have different slew rates at the zero-crossing.

ry instrument has input hysteresis. This is necessary to prevent noise from

Eve causing erroneous input triggering. The width of the hysteresis band determines the maximum sensitivity of the instrument. It is approximately 30 mV, so when you set a trigger level of 0 V, the actual trigger point would normally be +15 mV and the recovery point –15 mV. This kind of timing error is canceled out by using hysteresis compensation.

Hysteresis compensation means that the microcomputer can offset the trigger level so that actual triggering (after offset) equals the set trigger level (before offset). This general hysteresis compensation is active in phase, time interval, and rise/fall time measurements. There is a certain residual uncertainty of a few mV and there is also a certain temperature drift of the trigger point.

The nominal trigger point is 0 V with an uncertainty of ± 10 mV.

A sine wave expressed as:

has a slew rate of close to the zero-crosssing. This provides the systematic time error when crossing 10 mV, instead of crossing 0 mV.

The corresponding phase error in degrees is listed in the following table:

Frequency Phase error in degrees

160 MHz

100 MHz

10 MHz

1MHz

100 kHz

10 kHz and below

28.8°

18.0°

1.8°

0.18°

0.018°

0.002°

which can be reduced to:

This error can occur on both inputs, so the worst case systematic error is thus:

FCA3000, FCA3100, and MCA3000 Series User Manual 57

Phase Measurements

Methods of comp

ensation. The calculations above show the typical uncertainties

in the constituents that make up the total systematic phase error. For a given set of input signals you can compensate for this error more or less completely by making calibration measurements. Depending on the acceptable residual error, you can use one of the methods described below. The ﬁrst one is very simple but does not take the inter-channel propagation delay difference into account. The second one i

ncludes all systematic errors, if it is carried out meticulously, but it is

often not practicable.

Calibration measurement method 1.

1. Connect the test signals to Input A and Input B.

2. Select the function Phase A rel A to ﬁnd the initial error.

3. Use the Math/Limit menu to enter this value as the consta nt L in the formula

K*X+L by pressing X

4. The current measurement result (X

and change the sign.

) is subtracted from the future phase

measurements made by selecting Phase A rel B. A considerable part of the systematic phase errors will thus be canceled out. Note that this cal

ibration

has to be repeated if the frequency or the amplitude changes.

Calibration measurement method 2.

1. Connect one of the signals to be measured to both Input A and Input B using a

50 Ω power splitter or a BNC T-piece, depending on the source impedance. Make sure the cable lengths between power splitter / T-piece and instrument inputs are equal.

2. Select the function Phase A rel B and read the result.

3. Enter this value as a correction factor in the same way as described above

for M ethod 1.

4. To minimize the errors, keep the input signal amplitude constant to minimize

the deviation between calibration and measurement.

5. The same restrictions as for Method 1 regarding frequency and amplitude

apply to this method; you should recalibrate whenever one of the signal frequency or amplitude changes.

Common settings for the signal inputs are:

Slo

upling

Impedance

Trigger Manual

Trigger Level 0 V

ilter

Pos or Neg

Ω or 50 Ω depending on source and frequency

Off

58 FCA3000, FCA3100, and MCA3000 Series User Manual

Phase Measurements

Totalize (F

Residual syste

applying corrections according to one of the methods mentioned above, the systematic error is reduced, but not fully eliminated. The residual time delay error will most probably be negligible, but a trigger level error will always remain to a certain extent, especially if the temperature conditions are not constant.

CA3100SeriesOnly)

Menu path: Meas > Totalize.

The Totalize functions add up the number of trigger events on the two instrument inputs A and B. Five totalize functions are available.

In addition to controlling the gate manually by toggling Hold/Run (manual totalize function), you can also open and close the gate by using the arming facilities under Settings. The different functions are described below.

The display is updated continually while the gate is open. Events are accumulated during consecutive open periods until you do a Restart.

NOTE. T

Statistics functions or parameters like block and pacing.

he manual Totalize functions cannot be used in conjunction with the

matic error. By mathematically (on the bench or in the controller)

Totalize A

Totalize B

Totalize A+B

rigger does not work in the normal way for Totalize. An Auto Once action is

Auto t performed before the start of a totalize m easurement to calculate and set suitable trigger levels once.

This measurement lets you totalize (count) the number of trigger events on Input A. Auxiliary calculated parameters are A-B and A/B. Start/Stop is manually controlled by toggling the button Hold/Run, and the counting registers are reset by pressing Restart.

This measurement lets you totalize (count) the number of trigger events on Input B. Auxiliary calculated parameters are A-B and A/B. Start/Stop is manually controlled by toggling the button Hold/Run, and the counting registers are reset by pressing Restart.

This measurement lets you calculate the sum of trigger events on Input A and Input B. Auxiliary parameters are A and B. Start/Stop is manually controlled by toggling the button Hold/Run, and the counting registers are reset by pressing Restart.

FCA3000, FCA3100, and MCA3000 Series User Manual 59

Phase Measurements

Totalize A–B

Totalize A/B

Totalize and Arming

This measureme Input A and Input B. Auxiliary parameters are A and B. Start/Stop is manually controlled by toggling the button Hold/Run, and the counting registers are reset by pressing Restart.

The TOT A–B MAN makes it possible, for instance, to make differential ﬂow measurements in control systems.

Example: The number of cars in a parking lot equals the number of cars passing the entrance (A) gate, minus the ones passing the exit (B) gate.

This measurement lets you calculate the ratio of trigger events on Input A and Input B. Auxiliary parameters are A and B. Start/Stop is manually controlled by toggling the button Hold/Run, and the counting registers are reset by pressing Restart.

By using Arming together with Totalize you can open and close the gate with an external signal applied to one of the channels A, B,orE. In this way you can access functions like TOT A Start/Stop by B, TOT A-B Gated by E,and TOT B Timed by A, by selecting channel, slope and delay time for Start/Stop.

Unlike the manual Totalize functions, the armed totalize functions allow block and pacing control. So all the Statistics functions are available. A new result is displayed after each stop condition.

nt lets you calculate the difference between trigger events on

NOTE. If you set Start arming, you must also set a Stop arming condition on

Input A, Input B, Input E, or Time.

Examples. The Arming parameters are in the menu Settings > Arm.

To set up the Totalize functions above, do the following:

Totalize A, Start/Stop by B.

1. Select Totalize from the Meas menu and then A.

2. Connect the signal to be measured to Input A.

3. Set the trigger level for Input A manually to a suitable value.

4. Connect the control signal to Input B.

5. Set the trigger level for Input B manually to a suitable value.

6. Push Settings > Arm and set the following parameters:

Arm on Sample/Block: Decide if each event or each block of events

(Analysis mode) should be armed.

Start Channel:SelectB.

60 FCA3000, FCA3100, and MCA3000 Series User Manual

Phase Measurements

Start Slope:Se

Start Delay: Decide if you need to insert a delay (10 ns - 2 s) between the

control signal and the actual opening of the gate.

Stop Delay: Decide if you need to insert a delay (10 ns - 2 s) during which

the gate will not respond to the control signal on the Stop main application is to prevent relay contact bounces from closing the gate prematurely.

Stop Channel:SelectB.

Stop Slope: Select Positive slope (marked by a rising edge symbol).

Tot alize A-B gated by E.

1. Push Meas > Totalize > A-B.

2. Connect the signals to be measured to Inputs A and B.

3. Set the trigger levels for Inputs A and B manually to suitable values.

4. Connect the control signal (TTL levels) to Input E.

5. Pu

sh Settings > Arm and set the following parameters:

Arm on Sample/Block: Decide if each event or each block of events

(STATISTICS mode) should be armed.

lect Positive slope (marked by a rising edge symbol).

Channel. The

Start Channel:SelectE.

Start Slope: Select Positive slope (marked by a rising edge symbol).

Start Delay: Decide if you need to insert a delay (10 ns - 2 s) between the

control signal and the actual opening of the gate.

Stop Delay: Decide if you need to insert a delay (10 ns - 2 s) during which

the gate will not respond to the control signal on the Stop Channel. The main application is to prevent relay contact bounces from closing the gate prematurely.

Stop Channel:SelectE.

Stop Slope: Select Negative slope (marked by a falling edge symbol).

Totalize B timed by A. With this function you can synchronize the start of an accurate gate time to an external event.

1. Push Meas > Totalize > B.

2. Connect t

3. Set the trigger level for Input B manually to a suitable value.

4. Connect the control signal to Input A.

he signal to be measured to Input B.

FCA3000, FCA3100, and MCA3000 Series User Manual 61

Phase Measurements

5. Set the trigger

6. Push Settings > Arm and set the following parameters:

Arm on Sample/Block: Decide if each event or each block of events

(STATISTICS mode) should b e armed.

Start Channel:SelectA.

Start Slope: Select Positive slope (marked by a rising edge symbol).

Start Delay: Decide if you need to insert a delay (10 ns - 2 s) between the

control signal and the actual opening of the gate.

Stop Delay: Set the measurement time between 10 ns and 2 s.

Stop Channel:SelectTime.

level for Input A manually to a suitable value.

62 FCA3000, FCA3100, and MCA3000 Series User Manual

Voltage Measurements

MAX

MIN

,an

The instrument can measure the input voltage levels V input voltages (from –50 V to +50 V in two automatically selected ranges) and on repetitive 1% of the reading.

Push Meas >

The default low frequency limit is 20 Hz but can be changed using the Settings > Misc (mis higher low-frequency limit means faster measurements.

Selecti with full resolution. The other measurements are displayed along the bottom of the display in smaller characters.

Voltage measurements are determined by taking a series of trigger level settings and sensing when the instrument triggers.

signals between 1 Hz and 300 MHz. Measurement accuracy is about

Volt to open the voltage measurement menu.

cellaneous) menu to change the limit to between 1 Hz and 50 kHz. A

ng a voltage measurement displays that measurement in large digits and

MAX,VMIN

and VPPon DC

RMS

When the waveform (sinusoidal, triangular, square) of the input signal is known, its crest factor, deﬁned as the quotient (Q values, can be used to set the constant K in the mathematical function K*X+L. The display shows the actual V

s the main parameter.

For example, a sine wave has a crest factor of 1.414 (√2), so the constant in the formula above will be 0.354. To set this:

FCA3000, FCA3100, and MCA3000 Series User Manual 63

value of the input signal, assuming that V

rms

)ofthepeak(Vp)andRMS(V

rms

)

Voltage Measurements

1. Push Math/Limi

t > Math > Math(Off) > K*X+L.

2. Push K and enter 0.354.

3. Check that the L constant is set to its default setting of 0 (zero).

4. Conﬁrm your choices with the menu softkeys below the display and exit the

menus.

If the input is AC coupled and V

selected, the display shows the RMS value

of any sine wave input.

If the sine wave is superimposed on a DC voltage, the RMS value is found as:

0.354*V

If VDCis not known it can be found as:

To display the rms value of a sine wave superimposed on a DC voltage, follow the example above, but set L = V

64 FCA3000, FCA3100, and MCA3000 Series User Manual

Math and Statistical Measurements

Math and Stati

Averaging

stical Measurements

The instrume functions. You can use these functions separately or combine them.

The Frequency and Period Average measurements use hardware-based averaging (counting clock pulses during several full input signal cycles) for their averaged measurement results. All other measurements use a software-based mean average method to calculate the measurement average. Use the statistical Numerical mode to display averaged results for measurements other then Frequenc

Use Settings > Meas Time to set the measurement time (range is 20 ns to 1000 s, 20 ns res displays more digits (higher resolution) but fewer measurements per second. Meas Time is only applicable to Frequency and Period Average measurements.

The default Meas Time setting displays 11 digits and provides four to ﬁve measurements per second.

nts provide Averaging, Mathematics and Statistics post-processing

y and Period Average.

olution, and 200 ms default value). Increasing the measurement time

Mathematics

NOTE. To quickly select the lowest measurement time (20 ns), enter 0. The

instrument will select 20 ns automatically.

instrument has ﬁve predeﬁned mathematical expressions with which to

The process the measurement result before displaying the values on the screen. The available math expressions are:

K*X+L

/X+L

(K*X+L)/M

(K/X+L)/M

X/M-1

These expressions are in the Math/Limit > Math submenu.

X is a placeholder for the measurement result. The default values of K , L, and M are chosen so that the measurement result is not affected directly after activating Math. Recalling the default factory setting restores these values as well.

FCA3000, FCA3100, and MCA3000 Series User Manual 65

Math and Statistical Measurements

For example, to

measure the deviation from a certain initial frequency (instead

of measuring the frequency itself), do the following:

1. Recall the def

ault settings by pressing User Opt > Save/Recall > Recall

Setup > Default.

2. Connect the

signal to be measured to Input A.

3. Push Auto Set to let the instrument ﬁnd the optimum trigger conditions on

its own.

4. Push Math/Limit > Math > L.

5. You can set the value of L in one of two ways:

If the current measurement value is suitable for your purpose, then push

to transfer the value to the constant L. You can repeat pushing X0until

you have set the value you want.

Manually enter a numerical value by using the keypad.

6. Push Save|Exit to conﬁrm and save the value.

7. Push Math and select the expression K*X+L. The display shows the

deviation from the value that you entered.

Use the K constant to scale a measurement result.

Statistics

Use the expression X/M-1 if you want the result to be a relative deviation.

Statistics can be applied to all measurements and can also be applied to the result from Mathematics processing. You access statistical readouts by pushing the Analyze button to toggle.

The available statistics readouts are:

Max: Displays the maximum value within a sampled population of N xivalues.

in: Displays the minimum value within a sampled population of N x

values.

P-P: Displays the peak-to-peak deviation within a sampled population of Nx

values.

MEAN (as part of the main measurement readout): Displays the arithmetic mean value (x) of a sampled population of N x

values and is calculated as:

Std: Displays the standard deviation (s) of a sampled population of N values and is calculated as follows. It is deﬁned as the square root of the variance.

66 FCA3000, FCA3100, and MCA3000 Series User Manual

Math and Statistical Measurements

Adev: Displays the Allan deviation (σ) of a sampled population of N values and is calculated as follows. It is deﬁned as the square root of the Allan variance.

The number N in the statistic expressions is the number of samples, and is an integer value between 2 and 2*10

Allan Deviation Versus

Standard Deviation

Setting Sampling

Parameters

Allan deviation is a statistic used for characterizing short-term instability (such as typically caused by jitter and ﬂutter) by taking samples (measurements) at short intervals. The idea is to eliminate the inﬂuence of long-term drift due to aging, temperature, or wander by making consecutive comparisons of adjacent samples.

Standard deviation, which is probably a more familiar statistic, considers the effects of all types of deviation, as all samples in the population are compared with the total mean value.

Both Allan and Standard deviations are expressed in the same units as the main measurement, such as Hertz o

1. Push Settings > Stat.

2. Push No. of samples and enter a value by using the numerical buttons or the Up/Down arrow buttons. Push Save/Exit to save the value.

3. For histogram displays, push No. of Bins and enter a value. Push Save/Exit

to save the value.

4. Push Pacing time and enter a value (range is 2 μs - 500 s, default value 20 ms). The pacing parameter sets the sampling interval.

5. Activate the set pacing time by pushing Pacing Off to change it to Pacing On. Status Pacing Off means that the speciﬁed number of samples is taken

with minimum delay.

r seconds.

6. Push Hold/Run to stop the measuring process.

FCA3000, FCA3100, and MCA3000 Series User Manual 67

Math and Statistical Measurements

Statistics and

Measurement Speed

7. Push Restart to

8. Toggle Analyze to view the measurement result in each of the different

statistical p

NOTE. The instrument updates the screen with intermediate results until the

complete data capture is done.

When using long a time to perform. A measurement based on 1000 samples does not give a complete statistical result until all 1000 measurements are taken. It can take a long time to display a statistical measurement if the instrument setting is not optimal.

Here are a few tips to speed up the statistical measurement process:

Do not use Auto trigger. In Auto trigger mode, the instrument calculates the trigger levels before each measurement. Determine a good trigger lev el and set it manually.

Do not use a longer measuring time than is necessary for the required resolution.

Remember to use a short pacing time (measurement interval) if your application does not require data collection over a long period of time.

statistics, you must take care that a measurement does not take too

initiate one data capture.

resentation modes.

ermining Long or Short

Det

Time Instability

NOTE. The instrument displays intermediate results during the measurement

process.

When ma king statistical measurements, you must select measuring time in accordance with your measurement goal. For example, jitter or very short time (cycle to cycle) variations require that the samples be taken as single

easurements.

If average is used (Freq or Period Average only), the samples used for the

tatistical calculations are already averaged, unless the set measuring time is less

s than the period time of the input signal (up to 160 MHz). Above this frequency prescaling by two is introduced, and as a result a certain amount of averaging. This can be a great advantage when you measure medium or long time instabilities. Here averaging works as a smoothing function, eliminating the effect of jitter.

The signal in the following ﬁgure contains a slow signal variation as well as jitter. When measuring jitter you should use a limited number of samples so that the slow variation does not signiﬁcantly affect the measurement. You can alternatively use the Allan deviation statistic measure for this kind of measurement.

68 FCA3000, FCA3100, and MCA3000 Series User Manual

Math and Statistical Measurements

To measure the slower variation, calculate the Max, Min, or Mean values on a long series of averaged samples. Averaging eliminates the jitter in each sample and the long measuring time and large number of samples means that the measurement can record very slow variations. The maximum pacing time is 500 s, the maximum measuring time for each sample is 1000 s, and the maximum number of samples is 2*10

Statistics and Mathematics

Conﬁdence Limits

The instrument allows you to perform mathematical operations on the measured value before it is presented to the screen or to the bus. Any systematic measurement uncertainty can be measure d for a particular measurement setup, and the needed correction consta

nts can be entered into the appropriate math

operation. Statistics are then applied to the corrected measured value.

You can use standard deviation results to calculate the conﬁdence limits of a measurement.

Conﬁdence limits = ±ks

Where:

= standard deviation

k = 1 for a conﬁdence level of 68.3% (1σ – limits)

k = 2 for a conﬁdence level of 95.5% (2σ – limits)

k = 3 for a conﬁdence level of 99.7% (3σ – limits)

Example of calculating conﬁdence limits. The fol

lowing example calculates the

conﬁdence limits of a 100 μs time interval measurement. Use the Numerical statistics mode to read the mean value and standard deviation of the time interval. Take sufﬁcient samples to get a stable reading. Assume that the start and stop trigger transitions are fast and do not contribute to the measurement uncertainties.

FCA3000, FCA3100, and MCA3000 Series User Manual 69

Math and Statistical Measurements

Jitter Measurements

The instrument

Therefore the 95.5% conﬁdence limits = ±2s

displays a Mean value = 100.020 μs and a Std Dev = 50 ns.

(= ±2 * 50 ns) = ±100 ns.

The 3σ limit will then be ±3 * 50 ns = ±150 ns

Statistics provides an easy method to determine the short-term timing instability (jitter) of pulse signals. The jitter is usually speciﬁed with its rms value, which is equal to the standard deviation based on single measurements. The instrument can directly measure and display the rms jitter.

Otherwise, the standard deviation of mean values can be measured. The rms value is a good measure to quantify the jitter, but it gives no information about the distribu

tion of the measurement values.

To improve a design, it might be necessary to analyze the distribution. Use the instrum

ent statistical analysis functions to take trend analysis measurements. Push the Analyze button to step through the numeric and graphic statistical presentation modes.

You can gain greater analysis versatility by using a remote controller (GPIB or USB) and the optional TimeView™ Modulation Domain Analysis Software application.

70 FCA3000, FCA3100, and MCA3000 Series User Manual

Limit Testing

The Limits Mode makes the instrument an efﬁcient alarm condition monitor (limit tester). You can monitor measurement results in real time and set an action to take when a li the Limits menu.

mit condition is exceeded. Push Math/Limit > Limits to open

Limit Behavior

Use the Lowe

Push Limit Behavior to set how the instrument will respond on limit crossings. The available limit response behaviors are:

Off: Take no action. The LIM indicator is not displayed.

Capture: Capture the measurement that exceeds a limit setting and ﬂash the LIM indicator. Continue taking measurements. Only samples meeting the

test criterion are part of the population in statistics presentations.

Alarm:FlashtheLIM indicator and continue taking measurements. All samples, including those outside the limits, are part of the population in stati

Alarm_stop: Flash the LIM indicator and stop taking measurements (put instr limit detector to trigger. Only samples taken before the alarm condition are part of the population in statistics presentations.

The alarm conditions can also be detected using the SRQ function on the GPIB bus. See the FCA3000, FCA3100, and MCA3000 Series Programmer Manual.

r Limit and Upper Limit menu items to set the limit testing levels.

stics presentations.

ument in Hold). The instrument displays the measurement that caused the

ere are three limit testing modes:

LimitTestModes

FCA3000, FCA3100, and MCA3000 Series User Manual 71

Above: Measurements above the set lower limit will pass. A ﬂashing LIM

ymbol on the screen means that the measurement result w as below the lower

s limit at least once since the measurement started. Use Restart to reset the

LIM symbol to its non-ﬂashing state.

Below: Measurements below the set upper limit will pass. A ﬂashing LIM

symbol on the screen means that the measurement result was above the upper limit at least once since the measurement started. Use Restart to reset the

LIM symbol to its non-ﬂashing state.

Range: Measurements between (within) the speciﬁed limits will pass. A

ﬂashing LIM symbol on the screen means that the measurement result was below the lower limit or above the upper limit at least once since the measurement started. Use Restart to reset the LIM symbol to its non-ﬂashing state.

Limit Testing

Limits and Analyze Mode

If Range is sele representation of the current measurement value in relation to the limits can be seen at the same time as the numerical value.

The upper limit (UL) and the lower limit (LL) are vertical bars below the main numerical display, and their numerical values are displayed in s mall digits adjacent to the bars.

This type of graphic resembles a c lassic analog pointer instrument, where a happy face emoticon me ans that measurements are within the set limits. An unhappy face emoticon means that measurements are outside the set limits but are still within the display area. Measurements that fall outside the display area are represen

The location of the limit indicator bars is ﬁxed such that the limit range takes up the mid t length are set by the speciﬁed limits.

You can apply limit testing to trend plots and histograms (Analyze modes). Using limit scale length and resolution of the plots.

tedbya< attheleftedgeora> at the right edge of the screen.

hird of the screen area. This means that the resolution and the scale

s in trend plots and histograms inhibits auto-scaling and indirectly sets the

cted and the presentation mode is Va lu e,asimplegraphic

72 FCA3000, FCA3100, and MCA3000 Series User Manual

Arming

Arming starts and/or stops measurement acquisition when the instrument detects a change on a speciﬁed input signal. The available arming types are Arm Start and Arm Stop (in the Settings > Arm menu).

Arming is useful for taking frequency measurements in more complex signals such as:

Single-shot events or non-cyclic signals

Pulse signals where pulse width or pulse positions can vary

Signals with frequency variations versus time (proﬁling)

Guidelines

A selecte

Arming occurs when the instrument d etects the appropriate signal slope on the arming i the start arm detection to when to actually take the measurement, and a stop arm condition (slope and delay time) to extend the measurement period.

You can use Arm Start with all measurements except Frequency Burst, Ratio,andVol t. If you use star t arming with an average measurement, it only controls the start of the ﬁrst sample.

You can use Arm Stop with all measurements except Frequency Burst, Ratio, Vo lt,andRise/Fall Time.

Arming disables the normal free-run mode; no measurement is taken until the instrument detects a valid start arming signal condition.

You can use Input A, Input B, and Input E (on rear panel) for the start or stop arm source. The frequency range for Input A and Input B is 160 MHz. The frequency range for Input E is 80 MHz (TTL levels).

Arming measurements that use Input A or B as the arming signal are limited to 160 MHz signals, unless the arming condition within the signal occurs at a frequency lower than 160 MHz.

d part of a complex waveform signal

nput (Input A, Input B, or Input E). You can also set a delay period from

FCA3000, FCA3100, and MCA3000 Series User Manual 73

Arming

Start and Stop

Arm Start

Arming

Arm Start acts like an external trigger on an oscilloscope. It synchronizes the start of the actual measurement to a signal event. You can also use delay with the Arm Start functi Arm Start can be u sed alone to take a measurement, or combined with Arm Stop to take longer measurements.

The available Arm Start parameters are Channel, Slope, and Delay.

Signal sou line signals, or sweep signals, often generate a sync signal that coincides with the start of a sweep, length of an RF burst, or the start of a TV line. You can use this sync signal to arm the instrument.

on to delay the start of a measurement with respect to the arming pulse.

rces that generate complex waveforms like pulsed RF, pulse bursts, TV

Arm Stop

You can delay the start arming point with respect to the arming signal. Use this function when the external arming signal does not coincide with the part of the

al in which you are interested. The time delay range is 20 ns to 2 s with

sign a setting resolution of 10 ns.

Arm Stop halts a measurement when the instrument detects a level shift with

especiﬁed slope on the arming input signal. Combining Arm Start and Arm

th Stop results in a measurement gate function that sets the total duration of the measurement. For example, use an Arm Start/Stop combination to measure the frequency of a pulsed RF signal, where the position of the start/stop conditions are inside the burst.

74 FCA3000, FCA3100, and MCA3000 Series User Manual

Arming

Arm Start/Stop and Burst

Measurements

The available A

NOTE. Arm > Stop Delay time can only be used with the Totalize function in the

FCA3100 Series instruments.

Burst measurements taken by using Arm Start/Stop conditions use the normal Frequency measurement mode. However, burst measurements that are not taken using armi mode, where the instrument does its best to synchronize on the pulse bursts.

In time interval measurements, you can use the stop arming signal as a sort of “external trigger Hold Off signal.” Here you block stop triggering during the external period.

rm Stop parameters are Channel, Slope, and Delay.

ng conditions are done in the self-synchronizing Frequency Burst

Arming Input Signals

Input E (on the rear panel) is the normal arming input. It is suitable for arming (sync) signals that have TTL levels. The trigger level is ﬁxed at 1.4 V and cannot be changed. The trigger slope can be set to positive or negative.

You can also use Input A or Input B as arming inputs for all single and dual channel measurements (where the arming signal is one of the measuring signals). These inputs are more suitable if your arming signal does not have TTL levels. All Input A and Input B controls (such as AC/DC, Trigger Level, 50 Ω /1MΩ, and so on) can be used to condition the arming signal.

Using the Measuring Signal

As an Arming Signal

FCA3000, FCA3100, and MCA3000 Series User Manual 75

When performing time or frequency measurements on complex s ignals having a unique trigger point, you can use Input B arming to make the measuring signal “auto-arm” the instrument. The following example sets the instrument to measure the frequency of a signal after the signal reaches a speciﬁed voltage level:

Arming

1. Connect the signal to Input A,andtoInput B with a power splitter.

Arming and Setup Time

2. Push Inp

interest.

3. Push Inp

DC coupling and Manual triggering to set a speciﬁc level.

4. Push Se

Start Delay if required.

5. Set a m

nstrument has a 5 nanosecond setup time before the instrument can detect a

The i change on the arming signal.

ut A and adjust the settings to measure the waveform section of

ut B and adjust the settings to detect the unique trigger point. Use

ttings > Arm, enable arming, and set the Start Slope to detect. Use

easurement time that is a ppropriate for your signal area of interest.

76 FCA3000, FCA3100, and MCA3000 Series User Manual

Arming

Arming Examples

Thesetuptimei the time from the expired time delay until the measurement is armed (–60 to +40 ns, for a total of 100 ns delay resolution). The ﬁgure shows that a start trigger signal may be detected although it appears 60 nanoseconds before the programmed time delay has expired. The start trigger signal must come 40 nanoseconds after the programmed time delay expires to guarantee correct start of the measurement.

This section contains examples of how to measure a variety of burst signals. The ﬁrst two examples measure the pulse width of a selected positive pulse in a burst. The third example measures the time between pulses in a burst. You can also measure the period, rise time, or duty factor of the burst signals by selecting the appropriate measurement, as well as measure on a negative pulse by changing the trigger slope.

s different when using arming delay. The following ﬁgure shows

Arming Example:

Measuring the First Pulse

in a Burst

If you do not know the basic parameters of the signal to be measured, use an oscilloscope to determine the signal parameters. Use these parameters to set the instrument trigger slope, arming slope, and arming delay.

This example shows how to measure the width of the ﬁrst pulse in a repetitive pulse burst. In this example, a synchronization signal (sync) with TTL levels is also available. The quick and simple method described ﬁrst does not use arming at all but rather draws on the fact that the instrument tends to self-synchronize its internal processes to the input signal.

FCA3000, FCA3100, and MCA3000 Series User Manual 77

Arming

Thetaskistosy leading edge of the ﬁrst pulse. Depending on the signal timing, this can be easy, difﬁcult, or very difﬁcult.

Auto synchronization without arming. It is possible to measure a pulse within a burst without using the arming function. The instrument can often automatically synchroniz conditions for success are:

The PRF is n 150 Hz.

The durat substantially less than the distance to the next burst.

The numb miscounts.

Do the f

1. Connect the burst signal to Input A.

2. Set the manual sensitivity and trigger level until the burst signal triggers the

3. Push Meas > Pulse > Width Positive > A.

ollowing to perform auto synchronization without arming:

instrument correctly.

nchronize the start of the measurement (start trigger) to the

e the measurement start to the triggering of the ﬁrst pulse. The

ot too high, preferably below 50 Hz and certainly not above

ion of a pulse burst (between ﬁrst and last pulse) should be

er of pulses in the burst should be more than 100 to avoid occasional

4. Push Settings > Stat > Pacing to set Pacing to On.

5. Push Settings > Stat > Pacing Time and enter a value that is near the time

between the bursts.

Absolute synchronization is not guaranteed using this approach, but there is a good chance that auto-synchronization will work. However, occasional wrong values are displayed. To achieve guaranteed synchronization, use the Start Arming function.

Burst pulse synchronization using start arming. You can use an external sync signal to arm the measurement. This requires that the leading edge of the sync signal occurs more than 5 nanoseconds before the leading edge of the ﬁrst pulse in the burst (See Figure 9.)

Figure 9: Synchronization using Start Arming.

78 FCA3000, FCA3100, and MCA3000 Series User Manual

Arming

Do the followin

1. Connect the external sync signal toInput E (on the rear panel).

2. Connect the burst signal to Input A.

3. Adjust the trigger level to trigger on the burst signal.

4. Push Settings > Arm > Arm On > Sample.

5. Push Start Chan > E.

6. Push Start

7. Repeatedly push Save | Exit to return to the main screen.

8. Push Meas > Pulse > Width Positive > A.

If there is no (or too little) time difference between the arming signal and the ﬁrst pulse in the pulse burst, arming must be combined with a delay, as shown in the next example.

Burst Pulse Synchronization Using Start Arming With Time Delay. If the pulse bursts have a stable repetition frequency, you can use Start Arming with Time Delay to take the measurement. This method uses the sync pulse belonging to a preceding burst to synchronize the start of a measurement. Set the time delay to a time longer than the duration of a pulse burst and shorter than the repetition time

e pulse bursts, as show n in the following ﬁgure.

of th

g to perform synchronization using start arming:

Delay and verify or set the value to zero.

Figure 10: Synchronization using start arming with time delay.

Do the following to perform synchronization using start arming with time delay:

onnect the external sync signal toInput E (on rear panel).

1.C

2. Connect the burst signal to Input A.

3. Adjust the trigger level to trigger on the burst signal.

4. Push Settings > Arm > Arm On > Sample.

5. Push Start Chan > E.

6. Push Start Delay and enter a suitable delay value (longer than the duration of

a pulse burst but shorter than the repetition time of the pulse bursts).

FCA3000, FCA3100, and MCA3000 Series User Manual 79

Arming

Arming Example:

Measuring the Second

Pulse in a Burst

7. Repeatedly pus

8. Push Meas > Pulse > Width Positive > A.

This example shows how to measure the width of the second pulse in the pulse train. The problem is how to synchronize the measurement start to the start of the secon arming function) cannot work; auto synchronization only synchronizes on the ﬁrst trigger event in a burst. This means that this measurement needs to use the Arming function.

Depending on the sync signal’s position relative to th the sync signal, the m easurement can be performed with or without using arming delay. If the trailing edge of the sync signal occurs after the leading edge of the ﬁrst pulse but before the second pulse in the pulse burst, then normal start arming without delay can be used.

Select triggering on positive s lope on Input A and negative slope on Input E. The slope for the active arming channel is set in the Settings > Arm > Start Slope menu. The following ﬁgure shows when the trailing edge of the sync signal appears before the second pulse.

d pulse. In this case, auto synchronization (without the use of the

h Save | Exit to return to the main screen.

e burst, and the duration of

If the sync-pulse timing is not as suitable as in the above measurement example, such as when the trailing edge of the sync signal is too late, then combine arming with a time delay; as shown in the following ﬁgure.

Use the same procedure as in the preceding example but set a suitable Start Arm Delay so that delay expires in the gap between the ﬁrst and second pulse.

80 FCA3000, FCA3100, and MCA3000 Series User Manual

Arming

Arming Example:

Measuring the Time

Between Pulses in a Burst

In the previous measurement and performed a single-shot time interval measurement. The following example measures the time between the rising edge of the ﬁrst and fourth pulses in a burst, as shown in the following ﬁgure. This requires setting both a start and stop time to take the measurement.

This type of measurement uses the Time Interval A to A function, and the signal on Input B to control the stop conditions. The task is to arm both the start and the stop of this measurement. The start arming is already described in the ﬁrst arming example (synchronizing the measurement start to the leading edge of the ﬁrst pulse). The challenge is to synchronize the stop of the measurement (arm the stop). This can be done using either of the following methods:

examples, the synchronization task identiﬁed the start of a

Using trigger hold off to delay the stop a certain time. Trigger Hold Off is used to inhibit stop triggering during a preset time. The Hold Off period starts synchronously with the start trigger event. The Hold Off time should be set to expire somewhere between pulse number 3 and 4.

Use the same test setup as in the preceding examples. Then proceed as follows:

Push the Meas button and select Time Interval A to A.

Push Input B and choose positive slope and a suitable trigger level.

Push Settings > Trigger Hold Off (On) and enter a suitable Hold Off time.

FCA3000, FCA3100, and MCA3000 Series User Manual 81

Arming

Make sure the st no arming delay.

Measure the si

Usingstoparming(Externalhold off) to delay the stop. So far in these examples, the sync signal was used exclusively as a start arming signal; that is, the measurement triggering has focused on the leading edge of the sync signal, and not its duration. However, the sync signal can also be used as an External Trigger Hold Off by duration of the sync pulses can b e externally varied, select a duration that expires in the gap between the third and fourth pulses, as shown in the following ﬁgure.

using Stop Arming on the trailing edge of the sync signal. If the

art arming conditions from example #1 are maintained, that is

gnal.

Arming and Proﬁling

Use the same test setup as in the preceding example. Then proceed as follows:

1. Push Settings > Arm > Stop Chan > E.

2. Push Stop Slope > Falling.

3. Measure the signal.

Proﬁling means measuring frequency over time. Examples include measuring the warm-up drift in a signal source over hours, measuring the linearity of a frequency sweep during seconds, VCO switching characteristics during milliseconds, or the frequency changes inside a chirp radar pulse over microsecond periods.

These instruments can handle many proﬁling measurement situations, with some limitations. Proﬁling can theoretically be done manually, that is, by reading individual measurement results and plotting in a graph. However, the optimum wayistousetheinstrumentasafast,high-resolution sampling front-end, storing results in its internal memory, and then transfering the measurements to a software application for analysis and graphical presentation. The TimeView™ software application greatly simpliﬁes proﬁling.

There are two proﬁling measurements: free-running and repetitive sampling.

82 FCA3000, FCA3100, and MCA3000 Series User Manual

Arming

Free-Running

Measurements

Free-running m free-running measurements include determining the stability of an oscillator over a 24-hour period, measuring the initial drift of a generator during a 30-minute warm-up time, or measuring the short-term stability of a device. In these cases, measurements are taken at user-selected intervals in the range of 2 μs to 1000 s.

There are several ways to set a measurement interval:

Use pacing time (Settings > Stat) to set the measurement interval. Measurements continue until the set number of samples is taken. Use Hold/Run and Restart to stop a measurement after one full cycle. View the trend or spread on a statistical display (Trend Plot or Histogram) while the measurem

Use the timer in a remote controller. This allows for synchronization with externa components.

Use ext take measurements at 100 ms intervals.

Take m (continuous measurements), the shortest delay between measurements is approximately 4 μs (internal calibration Off) or 8 μs (internal calibration On) plus the set measurement time. For example, with a measurement time of

0.1 ms, the time between each sample is approximately 104 – 108 μs.

easurements are performed over a longer period. Typical

ent is proceeding.

l events, for instance a change of DUT when checking a series of

ernal arming signals. For example, use a 10 Hz arming signal pulse to

easurements in free-run mode. When the instrument is free-running

Repetitive Sampling

Proﬁling Measurements

Free-running measurements will not work when the proﬁling demands less than 4 μs intervals between samples. For example, how would you proﬁle a VCO step response with 100 samples during a 10 ms time period?

This measurement scenario requires a repetitive input step signal. You have to repeat your measurement 100 times, take one new sample per cycle, and delay each new sample by 100 μs with respect to the previous sample.

The easiest way to do this is by means of a controller, for example a PC loaded with TimeView software, although it is possible (but tedious) to manually set and perform all 100 measurements.

The following are required to set up a repetitive sampling proﬁling measurement:

A repetitive input signal (such as the frequency output of a VCO).

An external sync signal (such as the step voltage input to a VCO).

Useofarmingdelayedbyapresettime(100μs, 200 μs, 300 μs).

FCA3000, FCA3100, and MCA3000 Series User Manual 83

Arming

Figure 11: Setup for transient proﬁling of a VCO.

Figure 12: Results from a transient proﬁling measurement.

Use the results of all 100 measurements to plot frequency versus time. Note that the absolute a ccuracy of the time scale is dependent on the input signal itself.

hough the measurements are armed at 100 μs ±100 ns intervals, the actual start

Alt of measurement is always synchronized to the ﬁrst input signal trigger event after arming.

84 FCA3000, FCA3100, and MCA3000 Series User Manual

Appendix A: Default Instrument Settings

The following table lists the factory default instrument settings. Push User Opt > Save/Recall > Setup > Recall setup > Default to set the instrument to these

settings. (S

ee page 18.)

Parameter

InputA&B

Trigger Level Auto

Trigger Slope Rising (Positive)

Impedanc

Attenuat

Couplin

Filter

Arming

Start Off

Start Slope Rising (Positive)

Start Arm Delay

Stop Off

Stop Slope Rising (Positive)

Hold-Off

Hold-Off State Off

Hold-Off Time

Time-Out

Time-Out State Off

Time-Out Time

Statistics

Statistics Off

Number of Samples

Number of Bins

Pacing State Off

Pacing Time 20 ms

Mathematics

Math Constants

Limits

Limit State Off

Limit Mode Range

Lower Limit 0

Upper Limit 0

Default value

1MΩ

Off

200 μs

100 ms

100

Off

K=1, L=0, M=1

FCA3000, FCA3100, and MCA3000 Series User Manual 85

Appendix A: Default Instrument Settings

Burst

Sync Delay

Start Delay

Measure Time 200 μs

Freq. Limit 400 MHz

Miscellane

Function Freq A

Smart Frequency

Smart Time Interval Off

Measure Time 200 ms

g Low Freq

Auto Tri

Time bas

Blank Digits 0

ous

e Reference

400 μs

Auto

100 Hz

Auto

86 FCA3000, FCA3100, and MCA3000 Series User Manual

Tektronix FCA3000, FCA3003, FCA3020, FCA3100, FCA3103 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual