Used Agilent Agilent Used 53181A Manual

Agilent 53181A
225 MHz Frequency Counter

Operating Guide



Manual Part Number 53181- 90001

Printed in Mala y sia

NOTES

Agilen t 53181A Operating Guide

This guide describes how to use the Agilent 53181A 225 MHz Frequency Counter.

Agilent 531 81A 225 MHz Fr equen cy
Counter

Copyri ght 1994 - 2003

W

C

W

Agilent Techn olo gies , Inc.
All Rights Reserved. Reproduction,

adaptation, or translations without
prior written permission is
prohibited, except as all owed under
the copyright laws.

Print e d: November 2003
Printed in Malaysia

Manual part number
53181-90001

Certification and Warranty

Certification

Agilent Technologies certifies that
this product met its published
specification at the time of shipment
from the factory. Agilent
Technologies further certifies that its
calibration measurements are
traceable to the United States
National Institute of Standards and
Technology (formerly National
Bureau of Standards), to the extent
allowed by the Institute’s calibration
facility, and to the calibration
facilities of other International
Standards Organizat ion members.

Warranty

Agilent warrants Agilent hardware,
accessories and supplies against
defects in materials and
workmanship for a period of one year
from date of shipment. If Agilent
receives notice of such d efects d uring
the warranty period, Agilent will, at
its option, either repair or replace
products which prove to be defective.
Replacement products may be either
new or like-new.

Agilent warrants that Agilent
software will not fail to execute its
programming instructions, for the
period specified above, due to
defects in material and workmanship
when properly installed and used. If
Agilent receives notice of such
defect s during the warran ty period,
Agilent will replace software media
which does not execute its
programming instructions due to
such defects.

Safety Con siderations
General

This product and related
documentation must be reviewed for
familiarization with this safety
markings and instructions before
operation.

Before Cleaning

Disc on ne ct t he product fr o m
operating power before cleaning.

Warning Symbols That May Be
Used In This Book

Instruction manual symbol; the
product will be marked with this
symbol when it is necessary for the
user to refer to the instruction
manual.

Indicates hazardous voltages.

Indicates earth (ground) terminal.

or

Indicates terminal is connected to
chassis when such connection is not
apparent.

Indicates Alternating current.

Indicates Direct current.

Safety Considerations (contd)

ARNING

BODILY INJUR Y OR DEATH
MAY RESULT FROM
FAILURE TO HEED A
WARNING. DO NOT
PROCEED BEYOND A
WARNING UNTIL THE
INDICATED CONDITIONS
ARE FULLY UNDERSTOOD
AND MET.

AUTION

Damage to equipment, or in correct
measurement data, may result
from failure to heed a caution. Do
not proceed beyond a CAUTION
until the indicated conditions are
fully understood and met.

Safety Earth Ground

An uninterruptible safety earth
ground must be maintained from the
mains power source to the product’s
ground circuitry.

ARNING

WHEN MEASURING POWER
LINE SIGNALS, BE
EXTREMELY CAREFUL AND
ALWAYS USE A
STEP-DOWN ISOLATION
TRANSFORMER WHICH
OUTPUT IS COMPATIBLE
WITH THE INPUT
MEASUREMENT
CAPABILITIES OF THIS
PRODUCT. THIS PRODUCT’S
FRONT AND REAR PANELS
ARE TYPCIALLY AT EARTH
GROUND. THUS, NEVER TRY

TO MEASURE AC POWER
LINE SIGNALS WITHOUT AN
ISOLATION TRANSFORMER.

Agilent Techn olo gies , Inc. 7.NC.NL.A.11.03.97.R1.P.CW6FC
900 South Taft Avenue
Loveland, Colora do 80537 U .S.A.

Warranty (contd)

Agilent does not warrant that the
operation of Agilent products will be
uninterrupted or error free. If Agilent
is unable, within a reasonable time,
to repai r or replace any product to a
condition as warranted, customer
will be entitled to a refund of the
purchase price upon prompt return of
the prod u ct .

Agilent products may contain
remanufactured parts equivalent to
new in per formance or may have
been subjected to incidental use.

The warranty per iod begins on the
date of delivery or on the date of
installation if installed by Agilent. If
customer schedules or delays Agilent
installation more than 30 days after
delive ry, warranty begins on the 31st
day from delivery.

Warranty does not apply to defects
resul ting from (a) improper or
inadequate maintenance or
calibration, (b) software, interfacing,
parts or supplie s not supplie d by
Agilent , (c) unauthorized
modifi cati on or misus e, (d) operation
outside of the published
environmental specifications for the
product, or (e)improper sit e
prepar at i o n or ma intenan ce.

TO THE EXTENT ALL O WED BY
LOCAL LAW, THE ABOVE
WARRANTIES ARE EXCLUSIVE
AND NO OTHER WARRANTY OR
CONDITION, WHETHER
WRITTEN OR ORAL, IS
EXPRESSED OR IMPLIED AND
AGILENT SPECIFICALLY
DISCLAIMS ANY IMPLIED
WARRANTIES OR CONDITIONS
OF MERCHANTABILITY,
SATISF ACTORY QUALITY, AND
FITNESS FOR A PARTICULAR
PURPOSE.

Agilent will be liable for damage to
tangible property per incident up to
the greater of $300,000 or the actual
amount paid for the product that is
the subject of the claim, and for
damages for bodily injury or death,
to the extent that all such damages
are determined by a court of
competent jurisdiction to have been
directly caused by a defective
Agile nt product.

TO THE EXTEN T AL LO WED BY
LOCAL LAW, THE REMEDIES IN
THIS WARRA N TY STAT EMEN T
ARE CUSTOMER’S SOLE AND
EXCLUSIVE REMEDIES.
EXCEPT AS I NDICATED ABOVE,
IN NO EVENT WILL AGILENT OR
ITS SUPPLIERS BE LIABLE FOR
LOSS OF DATA OR FOR DIRECT ,
SPECIAL, INCIDENTAL,
CONSEQUENTIAL (INCLUDING
LOST PROFIT OR DATA), OR
OTHER DAMAGE, WHETHER
BASED IN CONTRACT , TORT, OR
OTHERWISE.

For consumer transactions in
Australia and New Zealand: the
warranty terms contained in this
statement, except to the extent
lawfully permitted, do not exclude,
restrict or modify and are in addition
to the ma ndatory statutory rights
applicable to the sale of this product
to you.

Assistance

Product maintenance agreemen ts and
other customer assistance agreem ents
are available for Agilent Technolo­gies pro du c t s.

For any assistance, contact your
nearest Agilent Technologies Sales
and Service Office.

Safety Considerations (contd)

WARNING

INSTRUCTIONS FOR
ADJUSTMENTS WHILE
COVERS ARE REMOVED
AND FOR SERVICING ARE
FOR USE BY SERVICE­TRAINED PERSONNEL
ONLY. TO AVOID
DANGEROUS ELECTRIC
SHOCK, DO NOT PERFORM
SUCH ADJUSTMENTS OR
SERVICING UNLESS
QUALIFIED TO DO SO.

WARNING

ANY INTERRUPTION OF THE
PROTECTIVE GROUNDING
CONDUCTOR (INSIDE OR
OUTSIDE THE PRODUCT'S
CIRCUITRY) OR
DISCONNECTING THE
PROTEC TIVE EARTH
TERMINAL WILL CAUSE
A POTENTIAL SHOCK
HAZARD THAT COULD
RESULT IN PERSONAL
INJURY. (GROUNDING ONE
CONDUCTOR OF A TWO
CONDUCTOR OUTLET IS
NOT SUFFICIENT
PROTECTION.)

Whenever it is likely that the
prote ct i o n ha s be e n impa i r e d , th e
instrument must be ma de inoperative
and be secured against any
unintended operation.

If this instrument is to be energized
via an autotransformer (for voltage
reduction) make sure the common
terminal is connected to the earthed
pole terminal (neutral) of the power
source.

Instructi ons for adjustments while
covers are removed and for servicing
are for us e by tra ined- pe r sonn el only.
To avoid dangerous electric sho ck,
do not per f orm such adjustments or
servici ng unless qualified to do so.

For conti nue d pro te cti on ag ain st fire ,
replace the line fuse(s) of the same
current rating and type (for example,
normal blow , time delay). D o not use
repaired fuses or short circuited
fuseholders.

Acoustic Noise Emissions

LpA<47 dB at operator position, at
normal operation, tested per
EN 27779. All data are the results
from type test.

Geräuschemission

LpA<47 dB am Arbeits
platz, normaler Betrieb, geprüft n ach
EN 27779.
Die Angagen beruh e n auf
Ergebnissen von Typenprüfungen.

7.NL.A.11.03.97.R1.P.CW6BC

I

I

II

DECLARATION OF CONFORMITY

According to ISO/IEC Guide 22 and CEN/CENELEC EN 45014

Manufacturer’s Name:
Manufacturer’s Address:

Declares, that the product

Product Name:
Model Number:
Product Options: This declaration covers all options of the above product.

Conforms with the following European Directives:

The product herewith complies with the requirements of the Low Voltage Directive 73/23/EEC and the EMC Directive 89/336/EEC
(including 93/68/EEC) and carries the CE Marking accordingly.

EMC Standard

IEC 61326-1:1997+A1:1998 / EN 61326-1:1997+A1:1998
CISPR 11:1990 / EN 55011:1991
IEC 61000-4-2:1995+A1:1998 / EN 61000-4-2:1995
IEC 61000-4-3:1995 / EN 61000-4-3:1995
IEC 61000-4-4:1995 / EN 61000-4-4:1995
IEC 61000-4-5:1995 / EN 61000-4-5:1995
IEC 61000-4-6:1996 / EN 61000-4-6:1996
IEC 61000-4-11:1994 / EN 61000-4-11:1994

Canada: ICES-001:1998
Australia/New Zealand: AS/NZS 2064.1

Agilent Technologies, Incorporated
Santa Clara Site
5301 Stevens Creek Blvd
Santa Clara, California 95051

Universal Counter Frequency Counter
53131A, 53132A 53181A

Limit

Group 1 Class A
4kV CD, 8kV AD
3 V/m, 80-1000 MHz

0.5kV signal lines, 1kV power lines

0.5 kV line-line, 1 kV line-ground
3V, 0.15-80 MHz I cycle, 100%

[1]

Safety

Supplemental Information:

[1]

The product was tested in a typical configuration with Agilent Technologies test systems.

Authorized EU-representative: Agilent Technologies Deutschland GmbH, Herrenberger Stra

Revision: A Document No. 53131A

IEC 61010-1:1990+A1:1992+A2:1995 / EN 61010-1:1993+A2:1995
Canada: CSA C22.2 No. 1010.1:1992

July 31, 2001

Date Art Nanawa, Product Regulations Manager

For further information, please contact your local Agilent Technologies sales office, agent or distributor.

β

e 130, D 71034 Böblingen, Germany

Contents

In This Guide

Contents and Organization xii
Related Documents xiii
Types of Service Available if Your Instrument Fails xiv

Standard Repair Services (Worldwide) xiv
Express Repair/Perf ormance Calibration Service (USA Only) xiv
Repair Instrument Yourself xiv

Repackaging for Shipment xv
Description of the 225 MHz Frequency Counter xvi
Options xvii

Hardware xvii
Support xvii

Accessories Supplied and Available xviii

Accessories Supplied xviii
Accessories Available xviii

Agilent 53181A Quick Reference Guide xix

1 Getti ng S tarted

The Front Panel at a Glance 1-2
The Front Panel Indicators at a Glance 1-3
The Front Panel Indicators at a Glance (Cont.) 1-4
The Front Panel Menus at a Glance 1-5
The Front Panel Menus at a Glance (Cont.) 1-6
The Front Panel Menus at a Glance (Cont.) 1-7
The Display Annunciators at a Glance 1-8
The Display Special Characters at a Glance 1-9

The Underscore Placeholder 1-9
The Asterisk Placeholder 1-9

Ope rati ng Guide iii

Contents

The Limit Test Graph Characters at a Glance 1-10
The Rear Panel at a Glance 1-11
Making Measurements 1-12

To Measure Frequency 1-14
T o Select Input Coupling and Impedance 1-15

Selecting Input Coupling 1-15
Selecting Input Impedance 1-15

To Set Input Channel Tr igger Level/Sensitivity 1-16

Changing Trigger Mode 1-16
Modifying Input Tr igger Level 1- 17
Selecting Input Trigger Slope 1-18
Selecting Input Sensitivity 1-18
Starting the Measurement 1-19

To Select Scale an d Offset 1-19

Entering th e Scale Value 1-19
Entering the Offset Value 1-20
Displaying the Math Results 1-21
Disabling Math 1-22

To Set Limits of Measurements 1-23

Setting the Upper Limit 1-24
Setting the Lower Limit 1-25
Setting the Count er to Flag and Stop Measuring On Out-of-Limit

Measurements 1-27
Setting the Counter to Flag On Limits But Continue
Measuring 1-28
Disabling Limit Testing 1-28
Disabling Math 1-29

T o Perform Statistics on Measurements 1-29

Selecting the Type of Sta tistics (Stats) 1-29
Computing Stats on Filtered Data Only 1-31
Displaying Stats After Filtering Data of Input Signal 1-33
Disabling Stats and Math 1-34

To Control Measurement 1-35

iv Operating Guide

Contents

2 Operat i n g Your F reque nc y C o unter

Introduction 2-2

Chapter Sum mary 2-2
Where to Find Some Key W orking Examples 2-3

How this Cou nt er Works for You 2-4
Summary of the Measurement Sequence 2-5
Using the Measurement Control K eys (Run and Stop/Single) 2-6

Overview of the Measurement Control Keys 2-6
To Use the Measu re men t Co n tro l Key s 2-7

Using Entry/Select (Arrow) Keys 2-9

To Use During Numeric Entry 2-9
T o Use When Sequencing Through the Other Meas and Recall

Menus 2-9
To Use During State Ch a ngi ng (O N/OFF, LO/MED/ HI, et c. ) 2-10
To Use on Prompted Help Messages (MATH HELP: NO/YES, PRT

HELP: NO/YES) 2-10

Using the MEASURE Menu Keys 2-11

Overview of the MEASURE Menus 2-11
To Measure Frequency 2-12
To Measure Frequency Ratio (Optional) 2-13
To Measure Period 2-13
To Measure Pos i tive/ Negative Vol t Pe aks 2-14

Using the Gate & External Arm M enu Key 2-15

Overview of Gate/External Ar ming Functions 2-15

TIME Arming 2-15
AUTO Arming 2-15
EXTERNAL Arming 2-15
DIGITS Arming 2-16

To Use the Gate and External Arm 2-17

Example Procedure for Gate and External Arm 2-17

Ope rati ng Guide v

Contents

Example Procedure for Changing the Number of
Digits of Resolution Displayed for More
Precise Measurements 2-19

Using the MATH Menu Keys 2-21

Overview of Scale/Offset Math Menu 2-21
To Use the Scale/ O ffset Ma t h Men u 2-22

Example Procedure for Scale Function 2-22
Example Procedure for Of fset Function 2-23
Example Procedure for Turning Off Math Mode 2-25
Example Procedure for Set Reference Function —Offset From the
Last Measurement Value (Seeing Digits Not Visible on the 12-
Digit Display) 2-25

Overview of Stati stics (Stats) Menu 2-26
To Use the Stats Menu for Automatic and Continuous Statistical

Analysis 2-27

Example Procedure for Computing S tats 2-27
Example Procedure for Easy Viewing of Stats 2-28
Example Procedure for Filt ering Da ta (Using Limits)
During Stats 2-29
Example Procedure for Configur ing SINGLE to Initiate N
Measurements 2-30
Example Procedure for Turning Off Stats Mode 2-30

Using the LIMITS Menu Keys 2-31

Overview of Limits Menus 2-31
To Set and Use Au t o m atic L imit Testin g 2-32

Limits Testing Example 1—Flag and Stop Measuring
On Limits 2-32

Limits Testing Example 2—Flag On Limits but
Continue Measuring 2-34
Limits Testing Example 3—Use Analog Gra ph Display While
Adjusting/Alig ning Input Signal 2-34

Limits Testing Example 4—Selecting Filtering Conditions of
Stats Computation 2-36

vi Operating Guide

Contents

Limits Testing Example 5—Sending the Limit-Detect Output to
the RS-232 Serial Port 2-38

Using the DISPLAY Digits Keys 2-39

Overview of the DISPLAY Digits Keys 2-39
To Use the DISPLAY Digits Keys 2-40

Using CHANNEL 1 Input Conditioning Keys 2-41

Overview of Trigger/Sensitivity Menu 2-41
To Use the Trigger/Sensitivity Key to Adjust Counter’s Trigger

Voltage and Sensitivity Level s 2-44
Overview of Input Conditioni ng Toggle Keys 2-47

Using the Save and Recall Menus 2-48

Overview of Save and Recall Functions 2-48
To Use the Save Function 2-49
To Use the Recall Function 2-50
To Unsave a Mea s urement Setup 2-51

Using the Pri nt Menu 2-52

Overview of the Print Menu 2-52
To Use the Print Men u 2-52

Using the Utility Menu 2-53

Overview of the Utility Menu 2-53
To Set the GPIB Ad d ress 2-54

Selecting Operating Mode (Talk/Listen, Talk-Only) 2-54

Setting the GPIB Address 2-54
To Choose the Timebase Source 2-55
To Run the Self-Test Routines 2-56

Overview of the Self-Test Routines 2-56

Example Procedure for Running the Self Test 2-57
To Configure the RS-232 Serial Port for Printing 2-58

Setting the Hardware Pacing 2-58

Setting the Baud Rate 2-59

Setting the Parity 2-59

Setting the Software Pace 2-59

Ope rati ng Guide vii

Contents

To Configure the RS-232 Serial Port for Sending Limit-Detect
Output 2-60

T o Select the Numerical Convention for the Display 2-61
T o Connect the Counter to a Serial Print er via the RS-232 Port 2-61
T o Connect the Counter to a Printer via GPIB 2-62
T o Select the GPIB Talk-Only Mode for Printing 2-62

Front Panel Display Message s 2- 63

Measurement Result Displa ys 2-63
Power-Up/Self Test Messages 2-64
Menu Messages 2-65
GPIB Messages 2-67

Preset Values After Power-up and *RST 2-68

Preset Values for Functions Accessibl e Via Front Panel or
GPIB 2-68

Preset Values for Functions Accessibl e Via GPIB Only 2-72

Common Qu es ti ons 2-74

Why is Stats result not avai lable yet? 2-74
Why won’t printer work? 2-74
Why did Counter stop measuring? 2-74
Why did Counter go to its default state aft er I set up my RS-232

port? 2-74
Counter’s numeric display does not follow the numerical conven tion

for my country. 2-74

3 Specifications

Introduction 3-2

Instrument Inputs 3-2
Instrument Inputs (Continued) 3-3
Time Base 3-4
Measurement Specifications 3-5
Measurement Specific ations (Continued) 3-6
Measurement Specific ations (Continued) 3-12
Measurement Definitions 3-15

viii Operating Guide

Index

Contents

Measurement Arming and Processi ng 3-16
General Information 3-17

Ope rati ng Guide ix

Contents

x Operating Guide

In This Guide

This book is the operating guide for the Agilent 53181A 225 MHz Frequency
Counter. It consists of a table of contents, this preface, a quick reference guide, three
chapters, and an index.

This preface contains the following information:

• Contents and Or ganization

• Related Documents

• Types of Service Available if Your Instrument Fails

• Repackaging for Shipment

• Description of the 225 MHz Frequency Counter

•Options

• Accessories Supplied and Available

page xii
page xiii
page xiv
page xv
page xvi
page xvii
page xviii

Ope rati ng Guide xi

In This Guide

Cont en t s and Organization

The Table of Contents lists the beg inning of each chapter in the gui de, helping you
locate information.

The Preface introduces you to the operating guide, the Frequency Counter , and
provides general information about the Counter.

The Quick Reference Guide consists of a Menu Tree (tear-out sheet) that serves as a
tool to trigger your memory or get you quickly reacquain ted with the instrument, and
Menu Roadmaps that illustrate how to navigate through the menus. It is located after
this preface.

Chapter 1, “Getting Started,” is a quick start guide that giv es you a brief overvi ew of
the Counter’s keys, indicators, menus, displa y, and connectors. Last, a graphical
procedure for perfor ming a complete measurement is provide d.

Chapter 2, “Operating Your Frequency Counter,” is an operator’s reference. You
are given an overview of each group of front-panel keys, operating functions, and
menus followed by a series of exe r cises that guide you through the operation of the
Counter.

Chapter 3, “Specifications,” list s the specif ications and characteristics of the Counter.

The Inde x helps you find items easily by arrangi ng information in a sequenc e
different from that found in the Table of Contents, disclosing relationships among
items.

xii Operating Gui de

In This Guide

Related Docum ents

For more information on counters refer to the following S eries 200 Application
Notes:

• Fundamentals of Ele ctronic Frequency Co unte rs Applica tion Note 200—Agilent
part number 02-5952-7506.

• Understanding Frequency Counter Specifications Application Note200-4—
Agilent part number 02-5952-7522.

Operating Guide xiii

In This Guide

Types of Service Av ai la bl e if Your Instrument Fai ls

If your Counter fails wit hin one y ear of origina l purch ase, Agilen t will repai r it free of
charge. If your instrument fails after your 1-year warranty expires, Agi lent will repai r
it, or you can repair it yourself by ordering the se rvice guide.

There are three type s of repair services:

• Standard repair service—if downtime is not critical.

• Express Re pair/Performance Calibration Ser vice—if downtim e is critical.

• Use the Assembly-Level Service Guide and repair the unit yourself.

Standard Repair Services (Worldwide)

Contact your nearest Agilent Technologies Service Center. They will arrange to have
your Counter repaired.

Express Repair/Performance Calibr ation Serv ice (USA O nl y)

If downtime i s crit ical , you c an receiv e yo ur repai red Counter via ove rnig ht shi pment.
Just call 1-800-4 03-0801 and ask for Express Repair/Perform ance Calibration
Service. When your Counter is r epa ired, it will be returned via overnight shipment.

Repair Instrument Yoursel f

If your Counter 1-year warranty has expired and you choose to repai r the instrument
yourself or would like more details on self-test and calibration, use the procedu r es in
the Asse mbly-Lev el Service G u ide.

xiv Operating Guide

In This Guide

Repackaging for Shipment

For the Express Repa ir/ Performance Calibr ation Ser vic e descri bed above , retu rn your
failed Counter to the designated Agil ent Service Center, using the shipping carton of
the instr u ment. Agilen t will notify you when your failed instrument has bee n
received.

If the instrument is to be shipped to Agilent for service or repair, be sure you do the
following:

• Attach a tag to the ins trument identifyi ng the owner and indicatin g the re quired
service or repair. Include the instrument model number and full serial number.

• Place the instrument in its original container (if availa ble) with appropriate
packaging mate rial.

• Secure the container with strong tape or metal bands.

If the original ship ping contain er is not availa ble, place your unit in a cont ainer which
will ensure at least 4 inches of compressible packaging material around all sides of
the unit. Use static free packaging materials to avoid additional damage to your unit.

Agilent Technologies suggests that you always insure shipments.

Ope rati ng Guide xv

In This Guide

Description of the 225 MHz Frequency Counter

The Agilent 53181A is a frequency counter capable of meas uring frequencies to 225
MHz on Channel 1. Depending on which optional Channel 2 the counter contains,
this capability is extended to 1.5 GHz (Option 015), 3.0 GHz (Option 030), 5.0 GHz
(Option 050) or 12.5 GHz (Option 124). T he Agilent 53181A has a freque ncy
resolution of 10 digits in one second.

The Agilent 53181A provides users with a GPIB measuring spee d of up to
200 measurements per second, and is suitable for bench-top and ATE operation.

The Agilent 53181A basic measurement functions include Frequency, Period, Peak
Voltage, and Frequency Ratio (if Channel 2 is ins talled).

The Agilent 53181A includes additio nal measurement functions and features that are
designed specifically for manufacturing and service applications:

• 1, 5, 10 MHz external reference capability—to match cust om er’s house standard,

• optional ultra high, high, or mediu m stability oven osci llators for high accuracy
needs and le ng t h en ed ca li b r at io n cy cles,

• external gating,

• full math and statistics,

• automatic limit testing,

• analog displ ay m ode limit testing, and

• SCPI programming capability.

Programmable control is performed via an GPIB. The GPIB and a talk-onl y RS-232C
serial port are sta ndard for the Agilent 53181A. The serial port is for printing
measured and ana lyzed data on serial printers, or for outputting an out-of-limit signal.

xvi Operating Guide

In This Guide

Options

The options available for th e Agilent 53181A 225 MHz Fr equency Counter a re listed
following this paragraph. Specif ications for the options are listed in Chap ter 3,
“Specifications.” If you’ve purchased an option with the initial order, it will be
installed a t the factory and ready for operation at delivery. Refer to the “Retrofitting
Optio ns” chapte r in th e A s sembly- L ev el S er v ice Guide f o r ins t r u ct io n s on f ield
installa tion of the options.

NOTE The “0s” an d “1s ” in the fo l lo w i n g opt i on numbers ar e numeric char a ct er s (th at is,

they are not lett ers).

Hardware

• Medium Stabi lity Oven Timebase, Option 001

• DC Power Input, Option 002

• High Stabi lity Oven Time bas e, Option 010

• Ultra High Stability Oven Timebase, Option 012

• 1.5 GHz RF Input Channel (Channel 2), Option 015

• 3.0 GHz RF Input Channel (Channel 2), Option 030

• 5.0 GHz RF Input Channel (Channel 2), Option 050

• 12.4 GHz RF Input Channel (Channel 2), Option 124

*

• Rear Terminal s

, Option 060

• Rack Mount Kit, Option 1CM

Support

• 5-year Return to Agilent for Repair, Option W50

• 5-year Return to Agilent for Calibra tion, Option W52

*

Channel 1 will have both front and rear terminals. Option 015 and Option 030 Channel 2 will have a rear

terminal only. Option 050 and Option 124 Channel 2 will have a front terminal only.

Ope rati ng Guide xvii

In This Guide

Accessori es Supplied and Availabl e

Accessories Supplied

• Power co r d , 2. 3 meters

Accessories Available

• Agilent 34161A Accessory Pouch

• Agilent 34131A Transit Case

• Printer RS-232 Interface cables, Agilent 24542G or Agilent 24542H

• GPIB cables, Agilent 10833A/B/ C/D

xviii Operating Guide

Agilent 531 81A Quick Re ference Guide

The Quick Reference Guide is designed for exp erienced users of the Agilent 53181A
Frequency Counter. It is intended to be used as a tool to trigge r your m emory. If you
are using the Agilent 53181A for the first time, Agilent recommends that you at le as t
read Chapter 1, “Getting Started,” in the Operating Guide first.

The Quick Reference Guide f ollows this page, and consi sts of the following items:

• A Menu Tree which may be torn out of the guide for external use (pages 1 and 2).

• Menu Roadmaps which illustrate via key -press sequences how to navigate
through the menus under the menu keys (pages 3 through 10). Key-press
sequences are provided for the following menu keys:

– Freq Ch1
– Freq Ch2
–Other Meas
–Gate & ExtArm
– Uppr & Lower
– Limit Mo de s
– Scale & Offset
–Stats
– Trigger/Sensitivity

Operating Guide xix

Preface

xx Operating Guide

Agilent 53181A

Frequency Counter

Freq
Ch 1

FREQUENCY 1

Freq
Ch 2

FREQUENCY 2

Uppr &
Lower

UPPR: 0.000000
LOWR: 0.000000

Other
Meas

PERIOD

1
RATIO 1 TO 2
RATIO 2 TO 1
VOLT PEAKS 1

Limit
Modes

LIM TEST: OFF

LIM TEST: ON

ON FAIL:GO ON

ON FAIL:

STOP

SHOW: NUMBER

GRAPH

SHOW:

GATE:

TIME

GATE: AUTO

TIME: .100 s

Scale &
Offset

SCALE:1.000000
OFFS: 0.000000
SET REF: NO

SET REF: YES
SET REF: HELP

MATH: OFF

MATH: ON

MATH HELP : NO

MATH HELP: YES

Gate &
ExtArm

GATE: EXTERNL

START: POS

START: NEG

STOP: AUTO

STOP: NEG
STOP: POS
STOP: TIME

TIME: .100 s

Stats

SHOW: MEAS

SHOW: STD DEV
SHOW:

MEAN

SHOW:

MAX

SHOW:

MIN
N: 100
STATS: OFF

STATS: ON

USE: ALL MEAS

USE: IN

LIMIT
ON SINGLE: 1

ON SINGLE: N

GATE: DIGITS

DIGITS: 4

1

Agilent 53181A

Frequency Counter

Recall

NO REGISTERS
RECALL 0
RECALL 1
RECALL 2
RECALL 3
RECALL 4
RECALL 5

RECALL 20

50Ω
1MΩ

CH 1: 50 OHM

CH 1: 1M OHM

Save &
Print

SAVE:
UNSAVE:
PRINT: OFF

PRINT: ON

PRT HELP: NO

PRT HELP: YES

DC
AC

CH 1: DC

CH 1: AC

AUTO TRG: ON
LEVEL: 50 PCT

SLOPE: POS

SLOPE: NEG

SENSTVTY: HI

SENSTVTY: LO
SENSTVTY:MED

X10
Attenuate

CH 1: X10 ATT

CH 1: X1 ATT

Trigger
Sensitivity

AUTO TRG: OFF

LEVEL: 0.000V

CH 1:

CH 1:

100kHz
Filter

LP FILT
NO FILT

2

Agilent 53181A
Frequency Counter

Freq
Ch 1

MEASURE

Freq
Ch 2

Other
Meas

Freq
Ch 1

Freq
Ch 1

FREQUENCY 1

Freq
Ch 2

Freq
Ch 2

FREQUENCY 2

Other
Meas

Other
Meas

Other
Meas

Other
Meas

Other
Meas

PERIOD 1

RATIO 1 TO 2

RATIO 2 TO 1

VOLT PEAKS 1

3

Agilent 53181A
Frequency Counter

Freq
Ch 1

FREQUENCY 1

MEASURE

– – – – – – – – – – – –

Gate &
ExtArm

Gate &
ExtArm

GATE: TIME

GATE: AUTO

GATE

: EXTERNL

Gate &
ExtArm

Gate &
ExtArm

GATE: DIGITS

STOP:

TIME: .100

Gate &

TIME: .100

ExtArm

TIME: .200

Gate &

START:

ExtArm

START: POS
START: NEG

STOP: AUTO
STOP: NEG
STOP: POS
STOP: TIME

TIME: .200

Gate &

DIGITS: 4

ExtArm

Enter

Enter

Gate &
ExtArm

Gate &
ExtArm

Gate &
ExtArm

RUN

RUN

RUN

DIGITS: 5

4

Enter

RUN

Agilent 53181A
Frequency Counter

Uppr &
Lower

LIMITS

Uppr &
Lower

Limit
Modes

Uppr &
Lower

Limit
Modes

Limit
Modes

UPPR: 0.000000

Uppr &

LOWR: 0.000000

Lower

LIM TEST:

Limit

ON FAIL:GO ON

Modes

Limit

SHOW: NUMBER

Modes

UPPR: 5.100000

LOWR: 4.900000

LIM TEST: OFF
LIM TEST: ON

ON FAIL:GO ON
ON FAIL: STOP

SHOW: NUMBER
SHOW: GRAPH

Enter

Enter

RUN

RUN

RUN

RUN

RUN

5

Agilent 53181A
Frequency Counter

Scale &
Offset

Scale &
Offset

MATH

Scale &
Offset

Scale &
Offset

Scale &
Offset

Scale &
Offset

Scale &
Offset

SCAL:

1.000000

OFFS:

0.000000

SET REF:

SET REF: NO
SET REF: YES
SET REF: HELP

MATH:

MATH HELP: YES

MATH HELP: NO

SCAL:

OFFS:

2.000000

0.500000

Enter

OFFS:-

Enter

Enter

nnnnnnn

MATH: OFF
MATH: ON

Enter

(MEAS X SCALE) + OFFS = RESULT

RUN

RUN

RUN

RUN

6

Agilent 53181A
Frequency Counter

Stats

Stats

MATH

Stats

SHOW:

SHOW: MEAS
SHOW:

STD

DEV

SHOW: MEAN

SHOW: MAX

SHOW: MIN

Stats

Stats

Stats

Stats

N: 100

N: 200

STATS:

STATS: OFF
STATS: ON

USE:

USE: ALL MEAS
USE: IN LIMIT

ON SINGLE:

ON SINGLE: 1
ON SINGLE: N

Enter

RUN

RUN

Run

Run

7

Agilent 53181A
Frequency Counter

Trigger
Sensitivity

Trigger
Sensitivity

CHANNEL 1

Trigger
Sensitivity

AUTO TRG:

Enter

Trigger
Sensitivity

Trigger
Sensitivity

Trigger
Sensitivity

Trigger
Sensitivity

AUTO TRG: ON

AUTO TRG: OFF

LEVEL: 0.000V

LEVEL: 2.000V

LEVEL: 50 PCT

LEVEL: 80 PCT

SLOPE:

SLOPE: POS
SLOPE: NEG

SENSTVTY:

SENSTVTY: HI
SENSTVTY: LO
SENSTVTY: MED

RUN

RUN

RUN

RUN

RUN

8

1

Getting Started

Chapter 1 Getting Started

5

9

8

The Front Panel at a Glance

The Front Pane l at a Glanc e

1

1

23

4

67

Remote
Error (Flashing)

SRQ

POWER

ON

Utility Menu:

STBY

Hold at power up

53181A

FREQUENCY COUNTER

Period Freq Ch 1 Ch 2 ExtRef

MEASURE LIMITS MATH DISPLAY CHANNEL 1

Freq
Ch 1

Other
Meas

Recall

Freq
Ch 2

Gate &
ExtArm

LocalUtility
Save &

Print

3 GHz

1 Measurement function menu keys
2 Limits menu keys
3 Math menu keys
4 Sign (+ or −) selecti on toggle key
5 Data Entry/Select (or arrow) keys
6 Enter numeric data (terminate) key. Also

tranverses a menu and exits at the end of a
menu.

7 Channel 2 optional RF input

10

Uppr &
Lower

Limit
Modes

Run

11

Scale &
Offset

Stats

Stop/
Single

CHANNEL 2

100 MHz to MAX

Limit

MHz
µs
Gate

More Digits

Fewer Digits

12

+/–

Enter

Trigger
Sensitivity

50Ω
1MΩ

DC
AC

X10
Attenuate

Damage Lvl:
5V rms MAX.50Ω

0.1 Hz − 225 MHz

Damage Lvl:
5V rms MAX.50Ω

13

100kHz
Filter

!

!

8 Utility men u key (Hold during power-up to access

Utility functions.)

9 Recall, Save and Print menu keys

10 Gate and Extern al Arm menu key

11 Measurement control keys
12 Display Digits keys
13 Channel 1 Tr igger/Sens itivity menu key and input

conditioning keys

NOTE It is normal operation for the fan in the Counter to conti nue to run af ter the Count er is

placed in Standby mode. Power to the timebase is continuous to maintain long term
measurement reliability, and the f an helps maintain timebase temperature stabilit y.

1-2 Operat ing Guide

Chapter 1 Getting Started

The Front Panel Indicators at a Glance

The Fro n t P a nel Indicat ors at a Glance

There are eight different group s of indicators or LEDs. They are li st ed and described
in the fo ll o w in g table.

Indicators Description of the In dicators

When the indicator for the Freq Ch 1 or Freq Ch 2 key s is

Freq
Ch 1

Other
Meas

Scale &
Offset

Stats

+/–

Freq
Ch 2

Limit
Modes

Local
Save &
Print

Trigger
Sensitivity

Enter

lit, it indica te s that t he Freque nc y func tion is ena bled fo r th e
corresponding input channel.

When the indicator for the Other Meas key is lit, it
simultaneously indicates that the key’s menu and its menu
item (for example, PERIOD 1) is enabled.

When these indicators are lit, the key’s “enable” menu item
(that is, Limit Modes/LIM TEST, Scale & Offset/MATH,
Stats/STATS, and Save & Print/PRINT) is enabled.

When this indicator is lit, it indicates that auto-trigge ring is
enabled.

When this indicator flashes, it indicates that the arrow keys
can be used to modify or enter data.

The Enter key is used to enter numeric values or
parameters. It can also be used to traverse through a menu.
Pressi ng the Enter key at the end or bottom of a menu will
cause the Counter to exit the menu and return to the
measuremen t m o de .

1

Run

Stop/
Single

When one of these indicators is lit, it indicates that the Run
or Single function is enabled.

Ope rati ng Guide 1-3

Chapter 1 Getting Started

The Front Panel Indicators at a Glance (Cont.)

The Front Panel Ind ic ators at a Glance (Cont.)

1

Indicators Description of the In dicators

When this i ndicator fl ashes, it indicates that the Counter is
triggering on the input signal. If the input signal is too high,
this indicator remains ON. If the input signal is too low, this
indicator is OFF.

50Ω
1MΩ

X10
Attenuate

Remote
Error (Flashing)

SRQ

DC
AC

100kHz
Filter

When one of these in dicators is lit, it indic ates that the
adjace nt choice (that is, 50Ω, DC, X10, or 100kHz Filter) is
enable d or acti ve. Not e t hat w hen thes e i ndica to rs ar e no t lit ,
then the other choice (that is, 1MΩ, AC, X1, or no filter) is
active.

A lit Remote indicator indicates that the Counter is in
remote mode (Note: In the remote mode, the Save & Print
key becomes the Local key.)

If (while in remote) an error occurs, the Remote indicator
will flash. The indic ator will continue flashing until the
controller has read or cleared the error queue, or until the
front panel returns to local mode.

An unlit Remote indicator indicates that the Counter is in
local mo de .

The SRQ indic ator indicates that the Counter has re quested
servi ce from the controller. The SRQ indicat or will remain
lit unti l th e con trol le r has rec ogn iz ed t he se rvice req ues t an d
seria l polled the Counter, or taken sp ecific action to cancel
the request (for exampl e, *CLS command) .

1-4 Operat ing Guide

Chapter 1 Getting Started

The Front Panel Menus at a Glance

The Fro n t P anel Menus at a Glance

Freq
Ch 1

Other
Meas

Gate &
ExtArm

1

FREQUENCY 1

Freq
Ch 2

FREQUENCY 2

1

Uppr &
Lower

UPPR: 0.000000
LOWR: 0.000000

PERIOD

1

1

RATIO 1 TO 2

1

RATIO 2 TO 1
VOLT PEAKS 1

Limit
Modes

LIM TEST: OFF

LIM TEST: ON

ON FAIL:GO ON

ON FAIL:

STOP

SHOW: NUMBER

GRAPH

SHOW:

2

GATE:

TIME: .100 s

TIME

Scale &
Offset

GATE: AUTO

SCALE:1.000000
OFFS: 0.000000
SET REF: NO

SET REF: YES
SET REF: HELP

MATH: OFF

MATH: ON

MATH HELP: NO

MATH HELP: YES

GATE: EXTERNL

START: POS

START: NEG

STOP: AUTO

STOP: NEG
STOP: POS
STOP: TIME

TIME: .100 s

Stats

SHOW: MEAS

SHOW: STD DEV
SHOW:

MEAN

SHOW:

MAX

SHOW:

MIN
N: 100
STATS: OFF

STATS: ON

USE: ALL MEAS

LIMIT

USE: IN

ON SINGLE: 1

ON SINGLE: N

GATE: DIGITS

DIGITS: 4

1

These menu items appear only if your Counter contains the optional 1.5 GHz, 3.0 GHz,
or 5.0 GHz RF Input (Channel 2).

2

Refer to Chapter 2 in this guide for details on the Gate & ExtArm menu.

Ope rati ng Guide 1-5

Chapter 1 Getting Started

The Front Panel Menus at a Glance (Cont.)

The Front Pane l Me nus at a G la nc e (Cont.)

1

Recall

3

NO REGISTERS

4

RECALL 0
RECALL 1
RECALL 2
RECALL 3
RECALL 4
RECALL 5

RECALL 20

50Ω
1MΩ

CH 1: 50 OHM

CH 1: 1M OHM

3

This appears when nothing can be recalled.

4

Only registers which can be recalled will appear in this menu.

5

This menu item only appears if an instrument setup has been saved.

Save &
Print

SAVE:

5

UNSAVE:
PRINT: OFF

PRINT: ON

PRT HELP: NO

PRT HELP: YES

DC
AC

CH 1: DC

CH 1: AC

Trigger
Sensitivity

AUTO TRG: ON
LEVEL: 50 PCT

SLOPE: POS

SLOPE: NEG

SENSTVTY: HI

SENSTVTY: LO
SENSTVTY:MED

X10
Attenuate

CH 1: X10 ATT

CH 1: X1 ATT

AUTO TRG: OFF
LEVEL: 0.000V

100kHz

Filter

CH 1:

LP FILT

CH 1:

NO FILT

1-6 Operat ing Guide

Chapter 1 Getting Started

The Front Panel Menus at a Glance (Cont.)

The Front Pane l Me nus at a G la nc e (Cont.)

NOTE Turn powe r of f, pre ss and h old R ecall (Utility) key, then pres s POWER key to access

this menu.

POWER

On / Stby

REV: X X X X
HP-IB: 3
TIMEBAS:

TIMEBAS:
TIMEBAS: EXT

CAL HELP: NO

CAL HELP: YES

TEST LOOP: OFF

TEST LOOP: ON

TST PRINT:OFF

TST PRINT: ON

Utility

Recall

AUTO
INT

TEST:

NO

6

TEST:

DISP

TEST:

CPU

TEST: ROM
TEST: RAM
TEST:

EEPROM

TEST:

HP-IB

TEST: QSPI
TEST: FPGA
TEST: FR END
TEST: MEAS
TEST: INTERP
TEST:

KEYPAD

TEST:

PRINT

BAUD: 9600

BAUD:

19200

BAUD: 300
BAUD: 1200
BAUD: 2400

PARITY: OFF

PARITY:

EVEN

PARITY: ODD

SW PACE: XON

SW PACE: NONE

DTR: HIGH

DTR: LIMIT
DTR:

HW PACE
SHOW 9 AS: 9.0

SHOW 9 AS: 9,0

1

6

These menu items appear only if TEST LOOP is OFF.

Ope rati ng Guide 1-7

Chapter 1 Getting Started

The Display Annunciators at a Glance

The Display Annunciators at a Glance

1

MHz

µs

Gate

Period Freq Ch 1 Ch 2 Limit ExtRef

Annunciator Indication

Period Counter is set to measure Period.
Freq Counter is set to measure Frequency.
Ch 1 Counter’s channel 1 is selected to measure an input si gnal.
Ch 2 Counter’s channel 2 is selected to measure an input si gnal.
Limit Counter is limit testing and the current measurement exceeds the user-

entered limits.

ExtRef Counter is set t o use the signal connected at rear panel Ref In

connect or as the timeba se (TIMEBAS: EXT); orCou nter is set to
automatically (TIMEBAS: AUTO) select the timebase and has chosen
the signal connected at the rear panel Ref In connector.

Hz The displayed data is in units of Hertz.
M The prefix for the unit s of the display ed data is mega (10

µ The prefix for the unit s of the display ed data is micro (10

s The display ed data is in units of seconds.
Gate The gate is ope n. Before a mea surement cycle starts, this ann unciator

is OFF, indicating the gat e is clo sed. D ur ing a mea surem ent cyc le , t he
annunciator is ON, indicating the gat e is open.

6

).

−6

).

1-8 Operat ing Guide

Chapter 1 Getting Started

The Display Special Characters at a Glance

The Display Special Characters at a Glance

Freq Ch 2

The Underscore Placeholder

Special C h aracter Description

A placeholder that indicates the digit has been blanked using
the Display Digits keys.

1

MHz

Hz

Freq Ch 1

The Asterisk Placehold er

Special C h aracter Description

A placeh older t hat i ndi cates t his digi t is not sign if icant be cau se
of the measurement resolution. (The appearance o f this
asterisk is determined by the Counter; thus, thes e cannot be
removed by the Display Digits keys.)

Ope rati ng Guide 1-9

Chapter 1 Getting Started

The Limit Test Graph Characters at a Glance

The Limit Test Graph Characters at a Glance

1

Freq Ch 1

Special C h aracter Description

The colon s represent the lower and upp er limits.

The asterisk represents the last measurement.

1-10 Operating Guide

Chapter 1 Getting Started

3

4

5 6 8 9

1 2

7

The Rear Panel at a Glance

The Rear Panel at a Glance

1

WARNING:

1

I
N
P
U
T
S

WARNING:

1 Rear-panel input connectors (optional)
2 Power modu le (Sen ses inc oming voltage

and automatically selects proper
setup.)

3 Fan

NO OPERATOR SERVICEABLE PARTS INSIDE, REFER SERVICING TO SERVICE TRAINED PERSONNEL.

!

60 VA

10 MHz Out

AC LINE:

50/60 Hz

50/60/400 Hz

100 - 120 VAC

200 - 240 VAC

ISM 1-A

FOR LABORATORY USE BY
QUALIFIED PERSONNEL
FOUR USAGE EN LABORATOIRE
PAR PERSONNEL QUALIFIE

OPTIONS

001 MS Oven
010 HS Oven
012 US Oven

To Configure:
Hold Recall during turn-on.

Osc Adjust

2

3

Ext
Arm

Ref
In

FOR CONTINUED FIRE PROTECTION, USE SPECIFIED ~ LINE FUSE.

6 10 MHz Output connector
7 GPIB (IEEE-488.1) interface conn ector
8 Oscillator Adjust potentiometer
9 RS-232 Inte rface or Limi t Output

connector

SERIAL PLATE

RS - 232

4 External Arm input connec tor
5 External Reference In put connector

NOTE It is normal operation for the fan in the Counter to conti nue to run af ter the Count er is

placed in Standby mode. Power to the timebase is continuous to maintain long term
measurement reliability, and the f an helps maintain timebase temperature stabilit y.

Ope rati ng Guide 1-11

Chapter 1 Getting Started

Making Measurements

Making Measurements

1

One of the first things you will want to do with your Counter is to become a cquainted
with its front panel. Therefore, we have written the procedures in this section to
familiarize you with some of its controls . Th e followin g procedures are provided:

• First you are shown how to turn on the Counter and measure the frequency of a
signal applied to the Counter’s input channels.

• Second, you are shown how to us e the input coupling, impedance, and
trigger/sensitivity keys to set the input conditions of Channel 1 to match the
signal being measured.

• Third, you are shown how to scale and offset the measurement result.

• Fourth, you are shown how to set upper and lower limits for measurements.

• Fifth, you are shown how to enable the Counter to compute statis tics (such as
standard deviation) and display statistics of measurements.

• Last, you are shown how to use the Run and Stop/Single keys to control
measurements.

The order of the procedures in this chapter is the recommended ord er for making
measurements wi th this Counter.

1-12 Operating Guide

Chapter 1 Getting Started

Making Measurements

Study and refer to the following legend, as nee ded, to understand the meaning of the
icons which are used throughout this chapt er.

12

34

1 Press key one time and

release

2 Press key two times and

release

3 Repeated key presses
4 Press and hold

5 Result
6 Auto operation
7 Connect signal
8 Disconnect signal

Legend

5

6

1

78

91110

9 Indicator off

10 Indicator on

11 Indicator flashing

Ope rati ng Guide 1-13

Chapter 1 Getting Started

Making Measurements

To Measure Fre quency

1

POWER

On / Stby

Period Freq Ch 1 Ch 2 Limit ExtRef

Freq Ch 1

Freq Ch 1

MHz

µs

Gate

Connect (for demonstr ation purposes) the Counter’s rear-panel 10 MHz Out signal to
CHANNEL 1 input as shown in the ill ust rated procedure, below.

CHANNEL 1

MHz

Gate

Damage Lvl:
5V rms MAX.50Ω

!

Freq Ch 1

The Counter will automatically display the measured frequency of the input signal.

1-14 Operating Guide

Chapter 1 Getting Started

Making Measurements

If you need or want to change CHANNEL 1’s coupling, impedance, and triggering
conditions to match the input signal you are trying to measure, the next procedures
“To Select Input Coupl ing and Impedance” and
“To Set Input Channel Trigger Level/Sensitivity” demonstrate this. Perform these
procedures whether or not you want to customize the Counter’s input conditions to
measure your signal ; doing this will help you become familiar with the DC/AC,

50Ω/1MΩ, and Trigger/Sensitivity keys.

To Select Input Coupling and Impedance

Selecting Input Coupling

DC
AC

Channel 1’s input coupling is now set to dc.

If you want to change the coupl ing back to the default ac coup ling, perform the
following s tep.

1

DC
AC

Selecting Input Impedance

50Ω
1MΩ

Channel 1’s input impedance is now set to 50Ω.

NOTE The “arrow” keys can also be use d to toggle the state of toggle keys (DC/AC,

50Ω/1MΩ, etc. ) as indica ted by t he fla shing i ndica tor withi n th e arrow ke ys. Ho wever,
for simplicity in this procedure, use the corre sponding toggle key to change states.

Ope rati ng Guide 1-15

Chapter 1 Getting Started

Making Measurements

If you want to change the input impedance back to the default 1 MΩimpedance,
perform the following step.

1

50Ω
1MΩ

Freq Ch 1

MHz

Gate

To Set Input Channel Trigger Level/Sensitivity

Changing Trigger Mode

Trigger
Sensitivity

Press any one of these arro w keys to toggle to the next state of Auto Trigger.

Enter

+/–

1-16 Operating Guide

Chapter 1 Getting Started

Making Measurements

Modifying Input T r igger Level

Trigger
Sensitivity

The leftmost “0” di git in the LEVEL display is highlighted, indicating that if you
press the d key once the displayed value will increase to 1.000 volt as shown in the
following s tep.

Enter

Channel 1’s trigger level is now set to +1V.

To set the trigger level to −2V, perform the following steps.

1

+/–

Enter

Channel 1’s trigger level is now set to −2V.

Ope rati ng Guide 1-17

Chapter 1 Getting Started

Making Measurements

Selecting Input Trigger Slope

1

Trigger
Sensitivity

Display 1, 7/13/92

Display 1, 7/13/92

Refer to the sub-s ection titled “To Use the Trigger/Sens itivity Key to Adjus t
Counter’s Trigger Voltage and Sensitivity Levels” in Chapter 2 for more information
about trigger slope, if needed.

Selecting Input Sensit ivity

Trigger
Sensitivity

Display 1, 7/13/92

Display 1, 7/13/92

Display 1, 7/13/92

Refer to the sub-s ection titled “To Use the Trigger/Sens itivity Key to Adjus t
Counter’s Trigger Voltage and Sensitivity Levels” in Chapter 2 for more information
about sensitivity, if needed.

1-18 Operating Guide

Chapter 1 Getting Started

Making Measurements

Starting the Measurement

MATH

Scale &
Offset

Stats

Run

Freq Ch 1

MHz

Gate

The Run key initiates repetitiv e meas urements, and is described in the sectio n titled
“To Control Measurement” at the end of this chapter.

To Select Scale and Offset

The Scale & Offset key allows for multiplication and a ddition, respectively, of the
measurement b y use r -specifi ed cons tant s. Mo difica tion of the di spla yed mea surement
by these Math operations is represente d by the following equation:

(Measurement × Scale ) + Off set = Di sp layed Re su lt s

The Scale and Offset Math operations can be used, for example, to subtract
systematic errors or display the pe rcentage difference between signals.

Entering the Scale Value

Scale &
Offset

1

To demonstrate the Sc ale Math operation, set Scale to 10 as shown in the following
steps.

Ope rati ng Guide 1-19

Chapter 1 Getting Started

Making Measurements

Press and hold the d key until the value of Scale is 10 as shown in the following step.

1

Enter

NOTE BE SURE to press the Enter key to enter the value of 10.

The Scale is now set to 10, and MATH has been enabled. The Scale & Offset
indicator is no w li t to show tha t M ATH is enable d . S in ce MATH is ena bled, th e
results are being scaled and offset.

Entering the Offset Value

To demonstrate the Offset Math operation, set the Offset to 1 MHz as shown in the
following steps.

Scale &
Offset

At this point, pressing the s key will cause the Counter to display the full display of
the Offset value as shown in the following step.

1-20 Operating Guide

Chapter 1 Getting Started

Making Measurements

Press the s key six more tim es to cause the Counter to dis play your entry in Mega
units as shown in the f ollowing step.

The leftmost “0” digit in the OFFSet display is highlighted, indicating that if you
press d key once the displayed value will increase to 1 Mega (that is, 1E6) as shown
in the fo ll owing st e p.

Enter

NOTE BE SURE to press the Enter key to enter the 1 Mega value.

The Offset is now set to 1 Mega.

Displaying the Math Results

M

1

M

M

Run

Freq Ch 1

M

The Counter displa ys the modifi ed measur ement result s, whic h are based on the scale
and offset value s that you selected in the pre vious steps. (For more details and real
applications of the Math Scale and Offset ope rations, refer to the appropriate section
in Chapter2, “Operating Your Frequency Counter.”)

Ope rati ng Guide 1-21

Chapter 1 Getting Started

Making Measurements

Disabling Math

1

Scale &
Offset

Display 1, 7/13/92

Display 1, 7/13/92

Note that the Scale & Offset key indicator is now off.

Run

Freq Ch 1

NOTE DO NOT cycle POWER because you will need to use these Scale and Offset values

in the following procedure “To Set Limits of Measurements.” Continue to the
following procedure.

MHz

Gate

1-22 Operating Guide

Chapter 1 Getting Started

Making Measurements

To Set Limits of Measurements

To demonstrate how Mat h and L im its work together, use the Scale (10) and Offset (1
Mega) values sele ct ed in the previous procedur e “To Select Scale and Offset. ” Enab le
Math by performing th e following steps.

Scale &
Offset

Display 1, 7/13/92

Display 1, 7/13/92

1

Run

Freq Ch 1

M

The result of this Math operation is a measurement of 101 MHz.

(Measurement × Scale) + O ffset = Result

(10 MHz × 10) + 1 Mega = 101 Mega

Now, set the upper limit to 102 Mega and the lower limit to100 Mega by performing
the following proc edures. (Figure 1-1 and Figure 1-2 illustrate the limits settings.)

Ope rati ng Guide 1-23

Chapter 1 Getting Started

Making Measurements

Setting the Upper Limit

LIMITS

Uppr &

1

Lower

Limit
Modes

Press the s key nine tim es to ca use the Counter to display your entry in hundreds of
Mega units as shown in the following step.

The leftmost “0” digit in the UPPR display is highlighted as shown above, indicating
that each pre ss of the d key will increase the displayed value.

Uppr &
Lower

M

M

Enter

NOTE BE SURE to press the Enter key to enter the 102 Mega value.

1-24 Operating Guide

M

M

M

Chapter 1 Getting Started

Making Measurements

1

2

1 102 Mega Upper Limit
2 101 Mega Scale/Offs et Measureme nt

Figure 1-1. 102 Mega Upper Limit Setting

Setting the Lower Limit

Uppr &
Lower

Press the arrow keys as shown in the following steps to set the lower limit value.
Press the s key nine tim es to ca use the Counter to display your entry in hundreds of
Mega units as shown in the following step.

1

Enter

NOTE BE SURE to press the Enter key to enter the 100 Mega value.

Ope rati ng Guide 1-25

M

M

M

Chapter 1 Getting Started

Making Measurements

Limits should now be set a s shown in Figure 1-2.

1

1 102 Mega Upper Limit
2 101 Mega Scale/Offs et Measureme nt
3 100 Mega Lower Limit

1
2

3

Figure 1-2. 100 Mega Lower and 102 Mega Upper Limits Settings

Figure 1-3 represents what transpired during this Math and Limits procedure.

1 Raw Me as u r e m en ts
2 Math

3 Limits
4 Measurements (Scale/Offset Results) within

Limits

Figure 1-3. Math and Limits Results

1-26 Operating Guide

Chapter 1 Getting Started

Making Measurements

Setting the Counter to Flag and Stop Measuring On Out-of-Limit
Measurements

If you want the Counter to stop measuring when the signal exceeds the limits (102 to
100 Mega) that you entered in the previous procedure, perform the followi ng steps to
select the STOP choice in the ON FAIL display . (Note that ON FAIL: GO ON is the
default state after power-up.)

Limit
Modes

Run

Freq Ch 1

M
Gate

The current modified measurement of the input sign al applied to CHANNEL 1 is
displayed.

Since the Counter is now in the stop-on-fail mode, the Limit annunciator in the
display will light and the Counter will stop m aking measurements when a
measurement excee ds the limits you set. The measurement result that exceeded the
entered limit s will be held on the display for observation.

1

Ope rati ng Guide 1-27

Chapter 1 Getting Started

Making Measurements

Setting the Counter to Flag On Limits But Continue Measuring

Perform the following steps to select the GO ON choice in the ON FAIL display if
you want the Counter to continue measuring e ven though an measurement result

1

exceeds the limits p r eviously entered.

Limit
Modes

Run

Freq Ch 1

M

Gate

The current modified measurement of the input signal applied to CHANNEL 1 is
displayed.

Since the Counter is now in the go-on-fail mode, the Limit annunc iator in the displa y
will light each time a measurement exceed s the limits you set. However, the Counter
will continue to make measurements.

Disabling Limit Testing

Limit
Modes

The Counter is now making measurements without limit testing.

1-28 Operating Guide

Chapter 1 Getting Started

Making Measurements

Disabling Math

Scale &
Offset

Display 1, 7/13/92

Display 1, 7/13/92

Run

Freq Ch 1

MHz

Gate

The Counter is now making measurements without the scale/offset values calculated
into the measurem en ts.

To Perform Statistics on Measurements

Selecting the Type of Statistics (Stats)

Suppose you want the Counter to compute and display the standard deviation of the
current input data (which is the 10 MHz signal appl ied to CHANNEL 1). Also, you
want the Counter to make 20 measurements before it computes the standard
deviation. Perform the following steps.

1

MATH

Scale &
Offset

Stats

Stats

Ope rati ng Guide 1-29

Chapter 1 Getting Started

Making Measurements

Updating the SHOW configura tion caused Stats to be enabled. The Stats indicator is
now lit.

1

Stats

Enter

NOTE BE SURE to press the Enter key to enter the value of 20.

1-30 Operating Guide

Chapter 1 Getting Started

Making Measurements

The Counter is now set to make sta tistics based on 20 measur ements.

Run

Freq Ch 1

Freq Ch 1

Freq Ch 1

Hz

Gate

Hz

Gate

In this case, the dis played standard devia tion value is computed on all measurements
of the 10 MHz signal since no limits were set.

Computing Stats on Filtered Data Only

A special featu re of the Counter allows you to use the upper and lower limits to filter
data before stat istical processing or computation as shown in Figure 1-4.

1

2

3

4

1

1 Raw Me as u r e m en ts
2 Limits

3 Filtered data (USE: IN LIMIT)
4 Statistics

Figure 1-4. Filtering Data Before Statistical Computation

Ope rati ng Guide 1-31

Chapter 1 Getting Started

Making Measurements

Perfo r m th e follo w in g s te ps to sele ct the IN LI M I T ch o i ce in the USE display if yo u
want the Counter to compute statistics on only frequency measurements within the
limits you set.

1

Stats

Display 1, 7/13/92

Display 1, 7/13/92

Since the Li mi ts were set to 100 Mega and 102 Mega values that are based on a s cale
of 10 and of fset of 1 Mega, you must re-enable Math now to get the measurements to
be within the lim its. Perform the following steps.

Scale &
Offset

Display 1, 7/13/92

Display 1, 7/13/92

1-32 Operating Guide

Chapter 1 Getting Started

Making Measurements

Displaying Stats After Filtering Data of Input Signal

Let’ s ass ume you ha ve set th e upper an d lowe r limit s for the input s ignal, and se lect ed
the IN LIMIT (filtering) choice. Now, perform the following steps to display the
standard deviation of the filtered measurements. (Note that the first step in the

followin g procedure is optional since you should have already set Stats to show
standar d deviation at th e beginning of this Stats procedur e. But, you may want to
perform the step anyway to verify that the Counter is displ aying the standard
deviation of the measurement.)

Stats

Display 1, 7/13/92

Run

Freq Ch 1

1

Freq Ch 1

Freq Ch 1

Gate

Gate

The standard deviation value shown in the previous illustration is for demonstration
purposes. The statistic is computed using only those measurements which fell within
the limits you set.

(For more deta ils o n the S ta ts and Li mits fun ct ions, ref er t o the a ppropria te se ction s in
Chapter 2, “Operating Your Frequency Counter.”)

Now, disable Math and Sta ts as shown in the following proc edure.

Ope rati ng Guide 1-33

Chapter 1 Getting Started

Making Measurements

Disabling S tats and Math

1

Stats

Scale &
Offset

Display 1, 7/13/92

Display 1, 7/13/92

Run

Freq Ch 1

MHz

Gate

The Counter is now making and displaying normal measurements (that is, the
Counter is not showing statistics or scale/offset results).

1-34 Operating Guide

Chapter 1 Getting Started

Making Measurements

To Control Measurement

Run Single/

Stop

Use these two keys to control the meas urement of the Counter. The Run key provide s
repetitive measurements, whereas the Stop/Single key allows you to make one
measurement.

With the 10 MHz signal still connected to CHANNEL 1, perform the foll owing steps
so you can better understand the Run and St op/Single operations.

Run

Freq Ch 1

MHz

Gate

The Counter is now making repetitive measurements (continuously making “live”
measurements).

Stop/
Single

Freq Ch 1

MHz

The Counter stopped making measurements. The Gate an nunciator is not lit. Hence,
pressing th e Stop/Single key while the Counter is making measurements (in Run)
causes the Counter to stop after the measurement in progress is completed. If you
press the Stop/Single key again whi le the Counter i s st opped, the Counte r will make a
single m e as u rement and th e n st op —the Gate annunciator will light one time,
momentarily.

1

If you press the Stop/Single key while the Counter is stopped and when the Stats
menu item ON SINGLE is set to N, the Coun ter will make N measurements and then
stop. This enables a set of statisti cs to be computed.

While the Counter is still stopped, perf orm the following step.

Run

Freq Ch 1

MHz

Gate

The Counter is making repetitive measurements again.

Ope rati ng Guide 1-35

Chapter 1 Getting Started

Making Measurements

1

1-36 Operating Guide

2

Operating Your Frequency Counter

Operator’s Reference

Chapter 2 Operating Your Frequency Counter

Introduction

Introduction

This is the operator’s reference chapter which contains inform ation and procedures
for the front-panel keys, operating functions, and menus of the Agilent 53181A 225
MHz Frequency Counter.

Chapter Summary

• How this Counter Works for You page 2-4

2

• Summary of the Measurement Sequence page 2-5

• Using the Measurement Control Keys (Run and Stop/Single) page 2-6

• Using Entry/Select (Arrow) Keys page 2-9

• Using the MEASURE Menu Keys page 2-11

• Using the Gate & External Arm Menu Key page 2-15

• Using the MATH Menu Keys page 2-21

• Using the LIMITS Menu Keys page 2-31

• Using the DISPLAY Digits Keys page 2-39

• Using CHANNEL 1 Input Conditioning Keys page 2-41

• Using the Save and Recall Menus page 2-48

• Using the Prin t Menu page 2-52

• Using the Utility Menu page 2-53

• Front Panel Display Messages page 2-63

• Preset Values After Power-up and *RST page 2-68

• Common Questions page 2-74

2-2 Operat ing Guide

Chapter 2 Operating Your Frequency Counter

Introduction

Where to Find Some Key Working Examples

• Example Procedure for Gate and External Arm page 2-17

• Example Procedure for Changing the Number of
Digits of Resolution Displayed for More Preci se Measurements

• Example Procedure for Scal e Function page 2-22

• Example Procedure for Offs et Function page 2-23

• Example Procedure for Set Reference Function—Offset From the
Last Measurement Value (Seeing Digits Not Vi sible on the 12­Digit Display)

• Example Procedure for Com puting Stats page 2-27

• Limits Testing Example 1—Flag and Stop Mea suring On Limits page 2-32

• Limits Testing Example 2—Flag On Limits but
Continue Measuring

• Limits Testing Example 3—Use Analog Graph Display While
Adjusting/Al igning Input Signal

• Limits Testing Example 4—Selecting Filtering Conditions of
Stats Computation

• Limits Testing Example 5—Sending the Limit-Detect Output to
the RS-232 Serial Port

page 2-19

page 2-25

page 2-34

page 2-34

page 2-36

spage 2-38

2

Ope rati ng Guide 2-3

Chapter 2 Operating Your Frequency Counter

How this Counter Works for You

How this Counter Works for You

The following text lists some of the key things the Counter does for you.

• The Counter presets the menus to default states and values at power-up (refer to

Table 2-6 for a detailed list of the preset values). Cycling the POWER key
presets the Counter.

• The Counter’s Utility menu a llows you to select such things as timebase source,
GPIB configuration, and RS-232 serial port configur ati on. After your selections,

2

the Counter automati cally stores all these se lections in non-volatile memory
(except the timebase source); thus, these settings (except timebase source) will
not change when power has been off or after a remote interface reset.

• The Counter automatically displays measurement(s) in a couple of seconds after
you select a measurement function (e.g., Period).

• The Counter accepts your numeric entry for a menu item after you pre s s the
Enter key. You MUST p ress th e En t e r ke y to complete num er ic entry.

• The Counte r automatically enables Lim its when you enter a num er ic value for
upper and/or lower limits, or update any menu item in the Limit Modes menu.

• The Counter automatically enables Math after you enter a numeric value for scale
and offset.

• The Counter perform s Statistical analyses for you, and will enable Stats when
you update any item in the Sta ts menu.

• The Counter automatically disables Limits, Math, and Stats when you select
another measurement function.

• The Counter saves measurement setup(s).

• The Counter instantly recalls the measurement setup you want to use.

• The Counter prints out your measurement and analysis data.

2-4 Operat ing Guide

Chapter 2 Operating Your Frequency Counter

Summary of the Measuremen t Sequence

Summary of the Me asurement Sequence

Use Utility menu to:

• choose the timebase source.

• configure the GPIB if you intend to operate the Counter remotely.

• set RS-232 serial port if you intend for the Counter to perform print ing and/or
limit-detecting.

Use MEASURE menu keys to select the measurement function.

Use CHANNEL 1 keys to set up input conditioning.

Use Gate & ExtArm key to:

• set the gate time and resolution.

•set arming.

Use Scale & Offset key to set up math operations.

Use Uppr & Lower key to set limits.

Use Limit Modes key to set up li mit testing.

Use Stats key to set up statistics and limit fi ltering.

Use Save & Print key to enable or disable printing.

Use Run and Stop/Single keys to control measurements.

2

Ope rati ng Guide 2-5

Chapter 2 Operating Your Frequency Counter

Using the Measurement Control Keys (Run and Stop/Single)

Using the Measur ement Control Keys
(Run and Stop/Single)

Overview of the Measurement Control Keys

Run Stop/

Single

T wo measur ement con trol key s are provided o n the Cou nte r: Run and Stop/Single. In
general, the Run key provides repetitive measurements while the Stop/Single key
allows you to make single-shot measurements.

The Run key allows you to:

2

• put the Counter into a continuous measurement loop.

• exit any measur ement after your selection of another measuremen t function.

• abort the current m easurement by starting a new measurement (if already in Run
mode or in Single mode with a measurement in progress). This also clears any
statistics being proc essed .

The Stop/Single key allows you to:

• put the Counter into Single mode (if the Counter was in Run mode) where one
measurement is taken with each Stop/Single keypress. (Stats menu item ON
SINGLE should be set to 1.)

• put the Counter into Single mode (if the Counter was in Run mode) where N
measurements are taken with each Stop/Single keypress. (Stats menu item ON
SINGLE should be set to N.)

• stop (abort) the current measurement (if the Counter was in Single mode).

2-6 Operat ing Guide

Chapter 2 Operating Your Frequency Counter

Using the Measurement Control Keys (Run and Stop/Single)

To Use the Measurement Control Keys

The following procedure demonstrates how these keys function.

1 Connect power source to Counter, and turn on Counter.

All segments of the front-panel display will light up while the Counter performs its
power-on self-test, and then dashes are displayed. The Counter is now rea dy to
measure frequency of a signal applied to CHANNEL 1 input. Note that the Freq and

Ch1 annunciators light.

2 Connect an input signal to CHANNEL 1.

The Counter aut omatically displays the measured freq uency of the input signa l. Note
that th e Run key indicator is ON.

3 Press Stop/Single key.

The Counter is put into Single mode and the current meas u rement is completed. One
measurement is taken with each press of Stop/ Single key. Note tha t the Stop/Single
key indicator is ON.

4 Press Run key.

The Counter aborts any measurement in progres s, and starts making repetitive
measurements. That is, the Counter is in a continuous measur ement loop.

5 Press Stop/Single key.

The Counter is put into Single mode.

6 Press Stats key until ON SIN GLE menu item appears, then press any one of the

arrow keys to set ON SING LE menu item to N.

The Counte r is set to take N measurements on each Stop/Single keypress (note: N =
100 at power-up). The state of ON SINGLE menu item affe cts the Stop/Single key
operation while statistics are enabled.

2

Observe t hat the Stats indica tor is ON. This indicates statisti cal processing is enabl ed.

Ope rati ng Guide 2-7

Chapter 2 Operating Your Frequency Counter

Using the Measurement Control Keys (Run and Stop/Single)

7 Press Stop/Single key.

One set of N frequ ency measur ements is tak en with e ach pre ss of the S top /Single key.
One set of stat istics is computed with each press of the Stop/Single ke y.

8 Press Stats key until SHOW me nu item appears.

9 Press any one of the arrow keys to select a stat is tical result to displ ay, and press

Freq Ch 1 key.

The Counter is now displaying one of the statistical results.

2

10 Press Stop/Single key.

One set of N frequ ency measur ements is tak en with e ach pre ss of the S top /Single key.
At the completion of the Nth measurement, the Counter displays the s tatistical result
selected in step 9.

11 Press Stats key until ON SINGLE menu item appears, then press any one of the

arrow keys to set ON SING LE menu item to 1.

The Counter is set to take one measurement on each Stop/Single keypress.

Disabling the statistics (with the STATS: OFF menu item) is anoth er way to cause
the Stop/Single key to initiate one measurement at a time.

2-8 Operat ing Guide

+/–

Enter

Chapter 2 Operating Your Frequency Counter

Using Entry/Select (Arrow) Keys

Using Entry/Select (Arrow) Keys

There are six entry/select keys of which four are “arrow” keys. The function of the
four arrow keys and the Enter key depends on the Counter’s operating mode (that is,
numeric entry, state changing, sequenci ng through choices in a menu, etc.). This
section describes how the keys perform in th e different oper ating modes.

To Use During Numeric Entry

• Use the s key to move left to selec t adjustable digits (it does not wrap around).

• Use the g key to move right to select a djustable digits (it does not wrap around).

• Use the d key to increment the sel ected (highlighted) digit of t he displayed value.

• Use the f key to decrement the selec ted (highlighted) digit of the displayed value.

•Use the +/− key to change the sign of the numeric value.

•Use the Enter key to complete a numeric entr y. (If a numeric entry is changed
and the Enter key is NOT pressed, then the value is not changed.)

2

To Use When Sequencing Through the Other Meas and Recall
Menus

• Use the d or s key to go back to the previous choice in a funct ion or recall menu.
Repeatedly pr essing this key will cycle through (and loop around) the list of
choices.

• Use the f or g key to go forwa rd or to the next ch oice i n a funct ion or rec all menu .
Repeatedly pr essing this key will cycle through (and loop around) the list of
choices.

•Use the Enter key to select th e function or execute the r ec all, or wait for the
menu to time out for automatic selection/execution.

To Use During State Changing (ON/OFF, LO/MED/HI, et c. )

•Press any of the arrow keys to toggle or cha nge to the next state of the
parameters found in the following menus:

– Gate & Ex tArm

Ope rati ng Guide 2-9

Chapter 2 Operating Your Frequency Counter

Using Entry/Select (Arrow) Keys

– Limit Modes
–Scale & Offset
– Stats
– Trigger/Sensitivity
–50Ω/1MΩ
–DC/AC
–X10 Attenuate
– 100kHz Filter

2

–Save & Print
– Utility Menu

•The +/− key is ignored during the st ate changing operati ng mo de.

T o Use on Prompted Help Messages (MA TH HELP: NO/YES, PRT
HELP: NO/YES)

• When MATH HELP: YES is di spla yed, press Enter key to displ ay the “(MEAS
x SCALE) + OFFS = RESULT” message.

• When PRT HELP: YES is displayed, press Enter key to display the
“CONFIGURE PORT ON UTILITY MENU; REMEMBER TO SA VE
SETUP FIRST” ins truction.

2-10 Operating Guide

Chapter 2 Operating Your Frequency Counter

Using the MEASURE Menu Keys

Using the MEASURE Menu Keys

Overview of the MEASURE Menus

MEASURE

Freq
Ch 1

Other
Meas

Freq
Ch 2

Gate &
ExtArm

The measurement function menus are divided into three categories:

• Frequency measurements on Channel 1.

• Frequency measu rem ents on Channel 2 (option al).

• Other measurements (period, ratio (optional), and peak voltage).

Table 2-1. Menus of the MEASUREment Keys

Freq Ch 1 key Freq Ch 2 key Other Meas key

FREQUENCY 1 FREQUENCY 2 (optional) PERIOD 1

RATIO 1 TO 2 (optional)
RATIO 2 TO 1 (optional)
VOLT PEAKS 1

To sequence thro ug h the Other Meas menu, you simply need to repeatedly press the
Other Meas key to cycle through (and loop around) the items (or measurement
functions) under the key. Each press of a Other Meas key will advance the Counter to
the next measurement function in the menu.

NOTE The menus under the MEASURE keys will terminate (select function and return to

measurement result display) after a sh ort timeout.

WARNING When measuring power line freque ncies, be extremely careful and a lway s use a step-

down isolation transformer of which output volta ge is compatible with the input
measurement capabilities of this product. Since the shell of the BNC input connector
is grounded to the chassis of the instrument, the hot side of a n ac power line could be
connected to the BNC shell and create a direct short to ground. Theref ore, NEVER

TRY TO MEASURE AC POWER LINE FREQUENCIES WITHOUT AN
ISOLATION TRANSFORMER.

2

Ope rati ng Guide 2-11

Chapter 2 Operating Your Frequency Counter

Using the MEASURE Menu Keys

To Measure Fre quency

1 Connect power source to Counter, and turn on Counter.

All segments of the front-panel display will light up while the Counter performs its
power-on self-test, and then dashes are displayed. The Counter is now rea dy to
measure frequency of a signal applied to CHANNEL 1 input. Note that the Freq and

Ch1 annunciators light.

2 Connect an input signal to CHANNEL 1.

The Counter shoul d autom atica lly dis play the meas ured freq uency of th e input s ig nal.

2

The trigger le vels are set to the 50% points of th e signal. However, you may disable
auto triggering, and change the trigger levels and slopes.

T o s et up CHANNEL 1’s coupling, impedanc e, an d tri ggering cond itions to match th e
input signal you are trying to measure, refer to the procedures “To Select Input
Coupling and Impe dance” and “To Set Input Channel Trigger Level/Sensitivi ty” in
Chapter 1, “Getting Started,” or the section titled “Using CHANNEL 1 Input
Condition ing Keys” in this chapter.

3 To measure the frequency of a signal applied to the option al CHANNEL 2 input,

press Freq Ch2 key.

FREQUENCY 2 will be momentarily displayed and the Freq and Ch2 annunciators
will light. Th e Counter will be ready to measure the fre quency of a signal applied to
CHANNEL 2 input.

Note that the Frequency 2 menu item is not avai lable in Counters tha t do not contain
the optional Channel 2.

2-12 Operating Guide

Chapter 2 Operating Your Frequency Counter

Using the MEASURE Menu Keys

To Measure Frequency Ratio (Optional)

1 Connect signals to be measured to channel s 1 and 2.

2 Press Other Meas key until RA TIO 1 TO 2 is displayed to measure the frequency

ratio between a signal applied to CHANNEL 1 input and a signal applied to the
optional CHANNEL 2 input.

RATIO 1 TO 2 will be momentarily displayed and the Freq, Ch1, and Ch2
annunciators will light. The Counte r will be ready to measure the f r equency ratio of a
signal applied to CHANNEL 1 in relation to a signal applied to CHANNEL 2
(Ch1/Ch2).

RA TIO 2 TO 1 is also available (Ch2/Ch1).

Note that Rati o 1 to 2 and Rat io 2 to 1 me nu items are not availa ble in Counters that
do not contain the optional Channel 2.

Note the result is not scale d by 10 0; it is not a percen tage.

2

The front-panel “arrow” (or entry/select) keys can also be used when sequen cing
through the Other Meas menu. Refer to the se ction titled “Using Entry/Select
(Arrow) Keys” for details.

To Measure Period

Press Other Meas key until PERIOD 1 is displayed.

PERIOD 1 is momentarily displayed, the Period and Ch1 annunciators light, and
the Counter is ready to measure the period of a signal applied to CHANNEL 1.

Ope rati ng Guide 2-13

Chapter 2 Operating Your Frequency Counter

Using the MEASURE Menu Keys

To Measure Positive/Negative Volt Peaks

Press Other Meas key until VOLT PEAKS 1 is displayed.

VOLT PEAKS 1 is momentarily displayed, the Ch1 annunciator lights, and the
Counter is re ady to m easu re minimu m and maxi mum volta ge peak s of si gnals appli ed
to CHANNEL 1.

NOTE In Volt Peaks funct ion, t he Co unter m easu res th e input s i gnal after th e s ign al has be en

conditioned by the input settings (impedance, coupling, attenuation, and filter). One
reminder of this is the (AC COUPLED) message, whic h is displayed when Voltage

2

NOTE Arming is not used for Voltage Peaks mea surement s. Also, Limi ts, Math, and Displ ay

Peaks is sele cted and the measurement channel is ac coupled.

The result is corrected for X10 attenuation.

Digits are not available for Voltage Peaks measurements.

2-14 Operating Guide

Chapter 2 Operating Your Frequency Counter

Using the Gate & External Arm Menu Key

Using the Gate & External Arm Menu Key

Overview of Gate/External Arming Functions

MEASURE

Freq
Ch 1

Other
Meas

Freq
Ch 2

Gate &
ExtArm

Table 2-2 lists the menus for all the arming configurations, an d shows how the Gate
and External Arming menu chan ges as a func tion of the arming mode.

The Counter has four arming modes: auto, external, digits and time. Thearming
modes are defined in the following paragraphs.

TIME Arming

For frequency, period, and frequency ratio, time arming means you can set the gate
time—the length of time for which your signal is measured.

NOTE Gate time and resolution are linked: the longer the gate time, the gr eater the

resolution. With an increase in resolution, you get a larger number of digits on the
display.

Time arm ing is dem onstrated in the sub-s ection titled “Example Procedure for Gate
and External Arm.”

AUTO Arming

For frequency, period, and frequency ratio, auto arming means make individual
measur ements as f ast as poss i b le.

EXTERN AL Arming

2

For frequency, period, and frequency ratio, external arming means you c an start a
measurement by using an external signal.

NOTE When external arming mode is enabled, a signal must be connected to the Count er’s

rear-panel Ext Arm connector.

Ope rati ng Guide 2-15

Chapter 2 Operating Your Frequency Counter

Using the Gate & External Arm Menu Key

DIGITS Arming

For frequency, period, and frequency ratio, digits ar ming means you can set th e number
of digits of resolution that you require your result to provide.

Digits arming is dem o n st r at ed in th e su b- section ti tled “Exa mp le Proced u r e fo r
Changing the Number of Digits Displayed.”

*Table 2-2. The Gate & External Arm Key Menus as a Function of the

Arming Mode

Frequency, Period, Ratio

2

Time Arming:

GATE: TIME
TIME: <time>

Auto Arming:

GATE: AUTO

Digits Arming:

GATE: DIGITS
DIGITS: <digits>

External Armi ng (Refer to page 2-17 or the Menu Roadmap in the Quick R eference
Guide, which follows the Preface, for more information.):

GATE: EXTERNL

START: POS

NEG

STOP: AUTO

NEG
POS
TIME

TIME: <time>

* There is no Gate and External Arm menu available for Voltage Peaks measurements.

2-16 Operating Guide

Chapter 2 Operating Your Frequency Counter

Using the Gate & External Arm Menu Key

To Use the Gate and External Arm

Example Procedure for Gate and External Arm

For demonstr ation purposes, you want t o set up the Counter so that it uses an external
arm to start a measurement. You want to make a Frequency measurement on a signal
applied to channel 1. Also, you want to perform the measurement during an interval
of 5 milliseconds as shown in the following figure.

NOTE As shown in the following figure, the Counter is alwa ys synchronized to the input

signal. Arming occurs on the rising edge of external arm (ExtArm), and the
measurement gate is synchronized to the trigger event on CHANNEL 1.

CHANNEL 1

Ext
Arm

2

Ext
Arm

Gate

5 ms

Perform the following procedure to accomplish this task.

1 Turn on the Counter, and press Stop/Single to put the Counter into the single

measurement mode.

2 Connect the signal to channel 1 input, and press Freq Ch 1 key.

3 Connect an external TTL signal to the Counter’s rear-panel Ext Arm connect o r.

4 Press Gate & ExtArm ke y.

GATE: TIME is displayed.

5 Press any one of the arrow keys until GATE: EXTERNL is displayed.

6 Press Gate & ExtArm or Enter key.

Ope rati ng Guide 2-17

Chapter 2 Operating Your Frequency Counter

Using the Gate & External Arm Menu Key

START: POS is displ ayed. (If START: NEG is displayed instead, then press any
one of the arrow keys to toggl e to the next state—POS).

7 Press Gate & ExtArm or Enter key.

STOP: NEG is displayed.

8 Press any one of the arrow keys until STOP: TIME is displayed.

9 Set the Gate Time to 5 m s by performing the following steps:

2

a. Press Gate & ExtArm or Enter key.

TIME: .100 seconds (the default time) is display ed.

b. Press the appropriate arrow keys until TIME: .00500 s is displayed.
c. Press Enter key.

NOTE BE SURE to press the Enter key to complete the numeric entry.

The counter will now gat e for a duration of 5 ms. The 5 ms interval will begin aft er
the external edge is detected.

10 Press Stop/Single key to start the measurement.

The measurement is started after the external arm pulse occurs.

2-18 Operating Guide

Chapter 2 Operating Your Frequency Counter

Using the Gate & External Arm Menu Key

Example Procedure for Changing the Number of Digit sof Resolution
Displayed for More Precise Measurements

1Turn POWER key OFF then ON again (cycle POWER key) to preset the Counter.

2 Connect (for demonstration purposes) the 10 MHz Out signal to the channel 1

input.

3 Press Other Meas key until PERIOD 1 is displayed.

After a few seconds, 0.100,000,000,0 µs is di spla yed. He nce, the de fault number of
digits (or resolution) di splays a precise measurement.

4 To demonstrate how to use “digits arming” to change the number of digits

displayed, perform the following steps first.

a. Press Gate & ExtArm key

GATE: TIME is displayed.

2

b. Press any one of the arrow ke ys until AUTO is displayed.
c. Press Enter or Run key.

0.100,0 µs is displayed. Note that fewer digits are displayed.

In “auto arming” you produce results quickly. The short gate time produces a
lower-resolution result.

Ope rati ng Guide 2-19

Chapter 2 Operating Your Frequency Counter

Using the Gate & External Arm Menu Key

5 To cha ng e the disp lay to th e better measurement re solution using digits armin g,

perform the following steps:

a. Press Gate & ExtArm key

GATE: AUTO is displayed.

b. Press any one of the arrow ke ys until DIGITS is display ed.
c. Press Gate & ExtArm or Enter key.

DIGITS: 4 is displayed (the default number of dig its )

2

d. To set the number of digits displayed to 8, pr ess the appropriate arrow keys until

DIGITS: 8 is displayed.

e. Press Enter key.
f. Press Run key.

0.100,000,000 µs is displayed.

1 2 3 4 5 6 7 8

Note that 8 digits of res olution are displayed (0.100,000,000 µs).

For the convenience of the user, the leading “1” does not count as a digit when 8
digits are selected; thus, a resul t of 0.099,999,999 µs can alternate with a result
of 0.100,000,000 µs with a stable display, and no change of settings is
required.

2-20 Operating Guide

Chapter 2 Operating Your Frequency Counter

Using the MATH Menu Key s

Using the MATH Menu Keys

Note tha t Math and Limits are not availab l e for Voltage Peaks measurements.

MATH

Scale &
Offset

Stats

Overview of Scale/Offset Math Menu

The Scale and Offset functions within the Math menu allow you to perform simple
mathematical operations on the measurem ent result before it is displayed. The Scale
and Offset functions allow for multiplication and addition. Modification of the
displayed meas urem ent by these math operations is represented by the following
equation:

(Measurement × Scale) + O ffset = Displayed Result

The mat h ope rat io ns c an be us e d, fo r ex amp le, to sub tra ct sys t emat ic erro r s or dis pl ay
the percentage difference bet ween signals. Also, the overall math operati on can be
disabled and then re-established without having to re-enter constants.

The menu items of the Scale and Offset Math functions allow you to:

• enter a desired multiplication factor for a measurement (SCAL:).

• enter a desired addition or subtraction val ue for a measu rem ent (OFFS:).

• get and display the last measurement val ue, and use it as a negative offset (SET
REF: NO or YES).

• disable or enable the Math mode (MATH: OFF or ON)—Note that the Math
mode is automatically enabled when you enter the scale and/or offse t value(s);
thus, the primary function of this menu item is to allow you to turn the Math
mode off.

2

• get Help, which displays the equation “( MEA S X SCALE) + OFF S =
RESULT ” to tell you how the scale and offse t results are computed by the

Counter (MATH HELP: NO or YES).

Ope rati ng Guide 2-21

Chapter 2 Operating Your Frequency Counter

Using the MATH Menu Key s

To Use the Scale/Offset Math Menu

Example Procedure for Scale Function

For demonstration purposes, you have a motor tha t has a tachometer attached to its
rotating shaft that generates a pulse for every revolution of the shaft.

Your task is to measure the speed or revolutions per minute (rpm) of the tachometer’s
output, and make the Counter directly display the measurement in rpm (which is
fundamentally a frequency measurement). The equation for this task is :

Frequency (Revolution/Sec) × Scal e ( 60 Sec/Min) =

2

1 Connect the output to channel 1 input, and press Freq Ch 1 key.

Results (Revolution/Min)

Perform the following procedure to accomplish this task.

The frequency of the signal is displayed.

2 Press Scale & Offs et key until SCAL: 1.000000 is displayed.

3 S et th e Sca le to 60 (sin ce there are sixty seco n ds in a minut e) b y perf o rming the

following steps:

a. Press appropriate arrow keys to s et Scale to 60.
b. Press Enter key.

NOTE BE SURE to press the Enter key to complete the numeric entry.

The scale is now set to 60 .

When th e scale factor is s et , bo t h sc al e an d offs e t ar e ap p l ie d to th e me asureme nt
result. Verify that the offs et value is zero for applica tions requiring only scale by
performing the following step.

4 Press Scale & Offs et key, if required, until OFFS: is displayed.

OFFS: 0.000000 should be displayed. If the Offset value is not set to “0.000000”:

2-22 Operating Guide

Chapter 2 Operating Your Frequency Counter

Using the MATH Menu Key s

a. Press the appropriate arrow ke ys to set the Offset to “0.000000.”
b. Press Enter key.

NOTE BE SURE to press the Enter key to complete the numeric entry.

The offset is now set to 0.

5 Press Run key.

The rpm measurement is displayed.
Note that units indicators Hz and s do not ap pear when MATH is ON.

Example Procedure for Off set Function

The offset function can be used to add or subtract a fixed value from measuremen t
results. This can be very us eful, for example , wh en tuni ng or alig ning odd freque ncies
of a loca l o scillator (LO). The targ et frequency can be entered as a negativ e offset,
then the Counter can display the differences between the LO’s frequency and the
target frequency. You can then adjust the LO until zero is dis played in the Counter’s
display.

2

Your task is to use the offset function to tune or align an LO to the target frequ ency of

222.127 MHz. Perform the following procedure to accomplish this task.

1Cycle POWER key to preset the Counter.

2 Connect the LO to channel 1, and press Freq Ch 1 key to measure the frequency

of the LO.

3 Press Scale & Offs et key until SCAL: is displayed.

4 S et S ca l e t o “1” by pres s in g t he a p propriate ar row k ey s t o ent e r t h e val u e

1.000000 if Scale is no t already set to “1.”

5 Press Enter key.

NOTE BE SURE to press the Enter key to complete the numeric entry.

Ope rati ng Guide 2-23

Chapter 2 Operating Your Frequency Counter

Using the MATH Menu Key s

6 Press Scale & Offs et key, if required, until OFFS: is displayed.

OFFS: 0.000000 should be displayed. This is the default value.

7 Set the Offset to -222.127 MHz.

Refer to the sub-section titled “Entering the Offset Value” in Ch apter 1, “Getting
Started,” for details on how to perform numeric entry for Offset.

a. Use the appropriate combination of the arrow keys to display a va lue of 222.127

MHz.

2

NOTE BE SURE to press the Enter key to complete numeric entry.

b. Press +/− key, which is located below the arrow keys, to change the pl us sign to

minus.
OFFS: -222.127 MHz is displayed.

c. Press Enter key.

8 Press Run key.

The resultant frequency is displayed with -222.127 MHz subtracted from each
measurement result.

The Counter displa ys the error or differences from the targeted 222. 127MHz.

For example, the dis play might indica te +000.023 MHz.

9 Adjust the LO as necessary until the Counter displays zero (00.000,000,0).

Your local oscillator is now properly aligned.

Example Procedure for T urning Off Math Mode

1 Press Scale & Offs et key until MATH: ON is displayed.

2 Press any one of the arrow keys.

2-24 Operating Guide

Chapter 2 Operating Your Frequency Counter

Using the MATH Menu Key s

MATH: OFF is displayed. Now, Scale and Offset no longer are used to modify the
displayed result.

3 Press Run key to return the Counter to its normal operation.

Example Procedure for Set Reference Function—Offset From the Last
Measurem ent Value (Seeing Digits Not Visible on the 12-Di g it Disp l ay)

The SET REF: YES menu item uses the negative of the last measurement value,
rounded to eleven digit s, to set the OFFSET. It also resets the scale value to 1. 0. Thus,
any di fference in the offset (or now the reference value) and the current measurement
value is displayed.

Let’s assume you are measuring the frequency of a stable source, but you are only
interested in the least significant digits of the measure me nt. Use the SET REF: YES
menu item to configure the appropriate OFFSET value.

Your task is to measure a stable sour ce to obtain the changes in the least significant
digits.

2

1Cycle POWER key to preset the Counter.

2 Change gate time to 15.0 seconds on GATE menu.

3 To demonstrate SET REF:, connect a 10 MHz sine wave signal to channel 1 of

the Counter, and press Freq Ch 1 key.

(Note that since the gate time is set to 15 seconds, it will take about 15 seconds to for
the Counter to dis play the measurement.)

10.000,000,000,1 MHz is displayed.

4 Press Scale & Offs et key until SET REF: is display ed .

5 Press the any one of the arrow keys to select SET REF: YES, and press Enter

key.

OFFS: −10.00000 M is displayed, for example.

Ope rati ng Guide 2-25

Chapter 2 Operating Your Frequency Counter

Using the MATH Menu Key s

Note that this value represents the las t m easurement of the input signal rounded to
eleven digits . The Counter uses it as the reference offset value, and reverses the sign
from + to − .

6 Press Run key.

−12* µ (120 µs) is displayed, for example, at the completion of the next me as urement.

This value (−0.00012) is the small difference between the signal being measured and
the reference value (OFFS: −10.00000 M) obtained in step 5.

Using the reference al lows you to observe small differences in the

2

13th–15th di gits which would not be obser vable in the 12-digit dis play.

Overview of Statistics (Stats) Menu

The Stats menu allows you to:

• select which computed statistics you want displayed

(SHOW: STD DEV , MEAN, MAX, or MIN).

• choose between ha ving the actual measu rem ent or statistical result displaye d

(SHOW: MEAS).

• select the number of measuremen ts you want to make for each compute d sta tist ic

(N:).

• enable or disabl e the Stats mode (STATS: ON or OFF).

• enable the Counter to perform statistical computation on only measurements that

are within the user-entered limits; that is, filter data (USE: IN LIMIT), or

• enabl e th e Counter to pe r f orm statis ti cal compu t at io n on al l m e asu r ements,

whether they fall in or out of the user-entered limits (USE: ALL MEAS).

• configure Stop/Single key to initiate a set of N measurements (ON SINGLE: 1
or N).

2-26 Operating Guide

Chapter 2 Operating Your Frequency Counter

Using the MATH Menu Key s

To Use the Stats Menu for Automatic and Continuous Statistical
Analysis

Example Procedure for Computing Stats

For demonstration purposes, let’s say you need to know the mean (average) and
minimum frequency values of a signal. Also, you want th e Counter to make 20
measurements before it performs these statistical computations.

Perform the following procedure to accomplish this task.

1 Connect the signal to channel 1 input, and press Freq Ch 1 key.

2 Press Stats key until N: is displayed.

N: 100 is displayed (100 is the default value).

3Set N to 20 (since you want the Counter to make 20 measurements before

computing the mean and minimum values) by pressing the appropriate arrow
keys.

N: 20 is displayed.

4 Press Enter key.

NOTE BE SURE to press the Enter key to complete numeric entry.

The Counter is now set to make 20 measurements before computing statistics.

5 Press Stats key until SHOW: is displayed.

6 Press any one of the arrow keys until SHOW: MEAN is displayed.

2

Ope rati ng Guide 2-27

Chapter 2 Operating Your Frequency Counter

Using the MATH Menu Key s

7 Press Run key.

Immediately after the Run key is pressed, the Counter momentarily displays DOING
STATS. When the Counter has made 20 valid measurements, it then displays the mean

frequency value of the input signal.

NOTE The Counter will display updated statistics results every 20 measurements.

8 Press Stop/Single key after you have a mean value displayed.

9 To disp lay the minimum frequency valu e, perform the following:

2

a. Press Stats key.
b. Press any one of the arrow ke ys until SHOW: MIN is displa yed.
c. Press Freq Ch 1 key.

CAUTION Pressing the Run key now would clear the present statistics results and calculate a

new set of results after “N” measurements.

Example Procedure for Easy Viewing of Stats

The d and f arrow keys provide a short cut to viewing eac h of the stats (that is, standard
deviation, mean, maximum, and minimum) when the Counter is already displaying a
statistic measurement. These keys allow you to cycle through the different Stats results
and automatically view them.

While th e C ou n t er is dis pl a y in g a sta ti st i cs measurement, press ei t her the d or f
arrow key to cycle through and display each of the four computed statistics, and
the current measuremen t .

NOTE The Display Digits keys (that is, More Digits and Fewer Digits) do NOT affe ct

standard deviation display results.

2-28 Operating Guide

Chapter 2 Operating Your Frequency Counter

Using the MATH Menu Key s

Example Procedure for Filteri ng Data (Using Limits) During Stat s

1 Using the procedure in the previous sub-section titled “Example Procedure for

Computing Stats,” set up the Counter to display the minimum frequency value
of an input signal.

2 Set the upper and lower limits. (Refer to th e section in Cha pter 1 titled “ToSet

Limits of Measurements” if needed.)

3 Press Stats key until USE: is display ed .

4 Press one of the arrow keys to toggle to IN LIM IT state.

USE: IN LIMIT is displayed.

5 Press Run key.

The Counter will now perform the statistica l computations (that is, standard
deviation, mean, maximum, and minimum) on only those measurements that are
within the user-entered limits. The Counter then displays the statistics you picked
(minimum, in this case).

6 Press Stats key until USE: is display ed .

7 Press any one of the arrow keys to toggle to ALL MEAS state.

USE: ALL MEAS is displ ayed.

8 Press Run key.

The Counter will now perform the statistica l computations (that is, standard
deviation, mean, maximum, and minimum) on all measurements, whether they fall in
or out of the user-entered limits. The Counter then displays the statistic you picked
(minimum, in this case).

2

Ope rati ng Guide 2-29

Chapter 2 Operating Your Frequency Counter

Using the MATH Menu Key s

Example Procedure for Configuri ng SI NGLE to Initiate N Measurements

Please re f er to th e p rocedure ti tl ed “To Use the Me asureme nt Co n tr o l Ke y s” on
page 2-7 in th is chapt er for an example use o f ON SINGLE.

Example Procedure for T urning Off Stats Mode

1 Press Stats key until STATS: ON is displayed.

2 Press any one of the arrow keys.

STATS : OFF is displayed.

2

3 Press Run key to return the Counter to its normal operation.

2-30 Operating Guide

Chapter 2 Operating Your Frequency Counter

Using the LIMITS Menu Keys

Using th e LIMITS Men u K e ys

Note tha t M ath and Limits menus are not available for Voltage Peaks measurements.

LIMITS

Uppr &
Lower

Limit
Modes

Overview of Limits Menus

The menu items under the Li mi ts keys allow you to:

• selec t the desired upper and lower measurement limits (UPPR:, LOWR:).

• disable or enable Limit Testing (LIM TEST : OFF or ON)—Note that the Limit

Testing is automatically enabled when you set the upper and lower li mits, or
update any me nu i tem in th e Lim it Mode s menu; th us, t he prim ar y functi on o f the
LIM TEST menu item is to all ow you to turn Limit Testing off.

• set the Counter to stop making measurements when a measurement exceeds the

user-ent ered limits (ON FAIL: STOP). (Stop on limits does not have any effect
if the Co unter is in th e s i ng l e measurement mod e.)

• enable the Coun ter to continue taking measurements after a measurement

exceeds the user-entered limits (ON FAIL: GO ON).

• change the Count er display from numeric to analog graph to quickly visualize
changes in the signal (or to quickly see when measurements are in or out of
limits) (SHOW: NUMBER or GRAPH).

2

Ope rati ng Guide 2-31

Chapter 2 Operating Your Frequency Counter

Using the LIMITS Menu Keys

To Set and Use Automatic Limit Testing

Limits Testing Example 1—Flag and Stop Measurin g On Limits

Automatic limit testing can be used to monito r a test signal to assure that it does not
drift outside of a us er-entered set of limits.

For demonstration purposes, you want to first measure the frequency of a 10 MHz
signal applied to channel 1 of the Counter. Next, you want to set limits that would
cause the Counte r to flag (turn on the Limits annunciator in the front-panel display)
and stop making measure me nts if this signal drifts more than ±1 kHz.

2

NOTE After you enter the value 10.001 MHz, BE SURE to press the Enter key to

1 Connect the 10 MHz input signal to channel 1 of the Coun ter, and press Freq Ch

1 key.

Assume that the frequency measure d is 10 MHz. If the drift is not to be larger than
±1 kHz, th en the uppe r limi t sho uld be set t o 10.001 MHz and the l ower lim it to 9.999
MHz. Let’s se t these values in the following st eps.

2 Press Uppr/Lower key until UPPR: is displ ayed.

UPPR: 0.000000 is displayed (0 is the defa ult value).

3Set UPPR to 10.001 MHz. (Refer to the se ction in Chapter 1 titled “To Set Limits of

Measu r em en ts” if need e d. )

compl et e th e ent r y.

4 Press Uppr/Lower key, if required, until LOWR: is displayed.

LOWR: 0.000000 is displayed (0 is the default value).

2-32 Operating Guide